fabrication and processing of grade 91 material

5/26/2018 Fabrication and Processing of Grade 91 Material

1/

INTERNATIONAL WORKSHOP ON

FABRICATION & PROCESSING OF

GRADE 91 MATERIAL

2526 February 2011

Tiruchirappalli

INDIA

Organised by


2/

PROGRAMME SCHEDULE

February 25, 2011

SESSION 1 GRADE 91 MATERIALSTUBES, PIPES

Introduction to Grade91, Applications of Grade 91,

chemical composition, mechanical and creep

properties, long term micro-structural evolution

Mr. Stefano Caminada

Tenaris, Italy

Production of tube and pipes, covering heat

treatment, linked to metallurgy of this grade and long

term properties and non destructive tests. The reason

of the recent evolution of ASTM regarding hardness.

V&M experience regarding influence of several post

welding heat treatment on base material and some

metallurgical recommendation concerning PWHT.

Mr. Bruno Lefebvre

V&M, France

SESSION 2 WELDING OF GRADE 91 MATERIALSPROCESSES, CONSUMABLES

Introduction to welding of Grade 91, Requirements on

Filler metal, Optimal welding parameters and heat

cycle, welding practice, filler metals for USC power

plants

Mr. Amitabha Bhattacharya

Bohler Welding Group India

Pvt. Ltd, Mumbai, India

Welding consumables for Grade 91 applications;

Special controls in chemistry; PWHT versus creep

properties; Difference between - B9 and -9Cb; Tips

for successful welding of P91 steel

Mr. Minoru Otsu

Kobe Steel, Japan

Dissimilar Welding of Grade 91 material with other

materials; Critical issues in welding

Dr. Raghvendra Srivastava

Metrode Products Limited

UK

SESSION 3 FABRICATION AND IN SERVICE BEHAVIOUR OF GRADE 91 MATERIALS . 1

Fabrication welding of 91 grade material The

special care that needs to be taken - Alstom

Experience

Mr. Robert Browning

Alstom, USA

Field welding of tubes and pipes in 91 grade material

Issues; experiences

Mr. G S Ravishankar

Tata Consulting Engineers

Bangalore, India

Performance of P91 weldment -- Type IV Cracking,

Site Welding Repairs; Dissimilar Weld Issues in

service

Mr. Perrin

Alstom, USA


3/

PROGRAMME SCHEDULEFebruary 26, 2011

SESSION 4 FABRICATION AND IN SERVICE BEHAVIOUR OF GRADE 91 MATERIALS . 2

New Generation compact induction heating

equipment for local Heat Treatment facilities for

Grade 91 material

Mr. C. N. Kumar

BHEL, Bangaluru, India

NDE of Grade 91 materials and weldment

RLA of Grade 91 Materials(after 15 years in service)

Mr. R. J. Pardikar

BHEL, Tiruchirappalli

Mr. P. Nagamanickam

BHEL, Tiruchirappalli

SESSION 5 GRADE 91 MATERIALSCASTINGS AND FORGINGS

Development of castings in supercritical steels

CFFP Perspective

Mr. V. K. Agarwal

BHEL, Haridwar, India

Development of fittings and forgings of F91

materialIndian Experience

Mr. N. D. Makkar

Flash Forge, Vizag, India


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BACK


35

V&M Experience in T/P91 Tub

Technica


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2

FAB 91 WorkshopTiruchirappalli - February 2011

Summary

Introduction on T/P 91

Tubes and Pipes Production

- Pre-material

- Hot rolling

- Heat treatment

- Mechanical properties on V&M products

- NDT

Focus on hardness

Focus on welding and PWHT


37

3


History of T/P 91

1950 Low alloy CrMo steels

1960 First super 9%Cr steel (EM12 = 9%Cr- 2%Mo- Nb-

1970 Development of 12%Cr, X20 in Germany

1982 Knoxville conference : Presentation of a 9Cr-1Mo s

1983-84 ASTM approves modified 9Cr-1Mo in A213 (T9Introduction of T91/P91 in ASME code.

1989: First V&M deliveries of T91 and P91

2000-2010: Large worldwide experience of the grade focritical and combined cycle boilers:

More than 300 000 tons of T/P91 delivered by V&M


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4


Main advantages of T/P 91Good mechanical characteristicand creep resistance up to 600C

Significant reduction of WTcompared to T/P22

Allow use at higher temperature

Good thermal conductivity

Low thermal expansionT/P22T/P22

(10Cr-Mo9-10)

Steam severe conditions

550 C - (1,020 F)

250 bars - (3,600 psi)

Reduct

T/P22T/P22(10Cr-Mo9-10)

Steam severe conditions

550 C - (1,020 F)

250 bars - (3,600 psi)

Reduct

T/P 91 is widely used in all sub-critical or super-critica

Super heater and reheater tubes

Headers

Main Steam piping and hot reheat piping


39


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6


Tubes and Pipes Production


41

7


Integration of our production process

Scraps, Iron Ore,Coke, Charcoal

Steel Making

Steel bar or ingot

Hot Rolling

Hot Finished Tubes and Pipes

Tubes and PipesManufacturing


42

8


V & M Steel and Tubes Works


43

9


Steel plant process for production of T

4 - A bowtype continuouscasting plant has replaced

the old vertical rotary caster

1 - Furnace loading 2 - Melting in the ultra-highpower electric furnace

3

6 - Ham5 - Cooling bed4 - A bowtype continuouscasting plant has replaced

the old vertical rotary caster

1 - Furnace loading 2 - Melting in the ultra-highpower electric furnace

3

6 - Ham5 - Cooling bed


44

10


Plug mill

Conti Mandrelmills:

MannesmannCross

Rolling

Piercing Elongation

PFPRotaryHearthFurnace

WalkingBeamFurnace

SoakingPitFurnace

Heating

Hot Rolling Process inside V&M

Mannesmann

Cross roll

piercing

Press

Drawing


45

11


Continuous Mandrel Mills

Outside diameters: 26.9 to 180 mm (1.1 t

St-Saulve

Mlheim


46

12


Main Process at Continuous Rolling

Billet Storage Billet saw

Piercing Mill Continuous mandrel Mill


47

13


Pierce and Draw Process

Outside diameters: approx. 300 to 1,500 m

WT : 20 to 150mm

Reisholz


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Production Steps in Reisholz

for Pipes up to 1500mm OD and 150mm

Ingot Vertical Piercing Press H

Heat Treatment

Boring

Straightening

Turning


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Photo of the Main Production Steps in

Vertical Piercing Press Ho

Heat TreatmentExternal grinding


50

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Example of P91 products

Dimensional range :

OD from 31.8 to 1500mm

WT from 3 to 150mm


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Heat Treatment:

a key point for the properties o


52

18


Heat treatment: a key point for quality

Batch furnace at Rath

Depending on the product size, heat treatment is pe

Batch furnace

Walking beam furnace

Tunnel furnace


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CCT Diagram of T/P91

AC1 : betdepend o

temperatu

Ms= mart

inter

Mf = mar

cooling p

Martensitabove 40of thick p


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Tempering curve of T/P91

Tempering at 750C / 780C optimum range for tensproperties


55

21


T/P91 Industrial Heat Treatment

730 to 800C

1040 to 1080C

ASTM

A 213 / A 335

7Tempering

10Normalizing

X10

Heat

TreatmentTemperature

Normalizing

Tempering

1050C - 1080C

750C - 780C


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Microstructure of T/P91

500:1 (etchantV2A)

Tempered martensite microstructure

Light optical microscopy Transmission e

Fine microstructutempered ma

M23 C6 M

MX M =


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Influence of the Pipe Wall Thickness o

Tensile Strength

P91 Tensile Strength

400

500

600

700

800

900

20 40 60 80 100 120

Pipe Wall Thickness

TS(MPa)

It is very important to well master the heat treatment proceproperties even for the whole range of thickness

Average data from different furnaces and diffe


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Mechanical Properties at Elevated Tem

on V&M Products in T/P91

Tens

0

100

200

300

400

500600

700

800

900

0 200

T

YS(MPa)

Yield Strength

0

100

200

300

400

500

600

700

800

0 100 200 300 400 500 600 700 800

Temperature C

YS(MPa)

minimum EN10216-2


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Creep tests: V&M data package

10

100

1000

1 10 100 1 000 10 000

Time [h]

CreepRuptureS

tress[MPa]

550C/1020F

600C/1100F

650C/1200F

More than 4 millions hours of test, with individual tests lonBased on tests from V&M industrial produ


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26


Non Destructive Tests:

a way to increase reliability of

products


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Non Destructive Test:

what is requested by the standards ?

Leak tigh

Hydros

Electromagneti

(Eddy current

A

Ultrasonic

Hydrostatic test

OR

Non Destructive Electric Test:

E 213 Ultrasonic examination

or

E 309 Eddy current

or

E570 Flux leakage

EN102

X10CrM

ASTM A 213 / A 335

T/P91


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V&M strategy for NDT

The V&M NDT concept ensure:

NDT adapted to the product and the productionprocess for an optimal defect detection

Full length NDT of all tubes and pipes

Automatic verification of Pipe Dimensions

Grade verification and Full Traceability


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Ultrasonic Test: essential for T/P91 to

rolling defects and cracks

Detection of :

Internal & External defects

Longitudinal & transverse defects

Lamination

WT measurement along the full length


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Other Non Destructive tests

Eddy Current complementary to UT for OD up to 180

To check the tube tightness

Thanks to multi-frequency EC also detects tranlongitudinal defects

Positive Material Identification (spectrotest) to chec

Magnetic Particle Inspection for large OD pipes or headbecause it requests a very fine surface preparation

Hydro-test: possible but really not necessary


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Non Destructive Tests mainly applie

V&M for T/P91

OD < 180mmEddy current: Multi-frequency E.C

Ultra Sonic Test (UT) to check:longitudinal defectsWall thickness

PMI: to check the grade

OD > 180 mmUltra Sonic Test (UT) to check:

Longitudinal defectsTransverse defectsLaminationWall thickness

PMI: to check the grade


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Focus on Hardness


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Hardness Requirement in Standards

New requirements on hardness for T/P91


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Where is this requirement coming from

Further to problems observed on 91 made components in seaction plan has been launched in order to determine easily thdefine criteria

Field Hardness testing of Grade 91 with portable devices hasas method linked with microstructural analysis on replicas. (1data points, 7 different units, 6 different fabrication shops, 3 dcontractors,)


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Link with the Microstructure

The final structure will consist in Tempered Martensite

A minimum hardness of 190HB is considered as a reliable

indication to get tempered martensitic structure without ferrite


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How to Measure Hardness on Tubes an

The hardness measurement is not basically well defined anit with the customer

Measurement on specimens or measurement on surface w

Example of measurement on thick pipes

Quadrant - Testing

In total,

9 Readings

Average value 190HB


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Critical Hardness Measurement on Sur

Measurement directly on surface (and not on sample) mdue to different reasons:

- Decarburization layer

- Surface hardening, by machining- Accuracy of portable devices

- Surface preparation

- Operator experience levels

- Etc


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Focus on Welding

Typical heating cycle

What is the influence of several PWHT What are the risks regarding PWHT


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Typical heating cycle for Welding P91

760C

400C

Preheating

200C

Slow heating

PWH

730 -76

Temperature

Necessary cooling down to RT after welding

Temperature range 20 / 100C

Welding Interpass

200 / 300C

200C

100C

760C

400C

Preheating

200C

Slow heating

PWH

730 -76

Temperature



Welding Interpass

200 / 300C

200C

100C

760C

400C

Preheating

200C

Slow heating

PWH

730 -76

Temperature



Welding Interpass

200 / 300C

200C

100C


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40


Influence of several PWHT on base ma

55C/4 h780C55C/h55C/4 h760C55C/h

CoolingHolding timeHolding

temperatureHeating rate

Test condition for 1 cycle


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41


Influence of several PWHT on hardnes

1 x

4h-780C

1 x

4h-760C 3 x

4h-760C

2 x4h-780C

2 x

4h-760C


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42


Influence of several PWHT on tensile p

Several PWHT are possible even if the mechanical prop

It is not necessary to specify too high value on base mat

But be careful with too high PWHT temperature

3 x

4h-780C1 x

4h-760C3 x

4h-760C

2 x

4h-780C

2 x

4h-760C

1 x

4h-780C3 x

4h-780C1 x

4h-760C3 x

4h-760C

2 x

4h-780C

2 x

4h-760C

1 x

4h-780C3 x

4h-780C

3 x

4h-780C1 x

4h-760C

1 x

4h-760C3 x

4h-760C

3 x

4h-760C

2 x

4h-780C

2 x

4h-780C

2 x

4h-760C

2 x

4h-760C

1 x

4h-780C

1 x

4h-780C

1 x

4h-760C 4h

2 x

4h-760C

1 x

4h-780C

1 x

4h-760C

1 x

4h-760C 4h4h

2 x

4h-760C

2 x

4h-760C

1 x

4h-780C

1 x

4h-780C


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43


What are the risks regarding PWHT:

Overheating

Influence of PWHT temperature on hardness

0

50

100

150

200

250

300

350

400

450

740 760 780 800 820 840 860 880 900

Tempering or PWHT temperature

HardnessHB

Transition

temperature AC1


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44


Short over-heating during PWHT

Influence of PWHT temperature on hardness

0

50

100

150

200

250

300

350

400

450

740 760 780 800 820 840 860 880

Tempering or PWHT temperature

HardnessHB

Transition

temperature AC1

Risk o

Sho


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45


Influence of Chemical composition on

Be careful !

AC1 is strongly influenced by Ni + Mn content

Take into account the chemical composition of


80

46


Conclusion

Thanks to a successful experience of 20 years in grade 91, V&M production and process control to fulfill the market evolution:

- High level of quality to get reliable products (creep qualificat- Broad dimensional range to supply the specific sizes of sup- Large quantity increase.

Even if T/P91 is used in most of the power plants in the world, the

demonstrated that damage could occur if manufacturing is not pe

Heat treatment and PWHT have a direct influence on microstructuproperties.

ASTM has recently introduced a minimum hardness requirement.reliable indicator to get the proper tempered martensitic microstru

Hardness measurement on sample in laboratory is more represeproperties than surface measurement with portative device.

Temperature of PWHT has to be carefully defined and mastered, chemistry of the consumable.


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Globa

Welding

Bhler Welding Grou

Am

Bohler W

IIM Trichy- FEB 20111

-


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Plant Hamm


Bhler Schweisstechnik Deutschland GmbH


83

Welding of P91

Content

Introduction

Optimal welding parameter and heat cycle

Welding practice

Filler metal for USC power plants



84

Tendency of development of the main steam parameters forPower plants

Japan USA Europ

25 MPa 27 MPa 28-30 MP

Near

future

630C 620C/ 28 MPa 600C / 62

(650C) 28- 30 MP25 MPa

Target2014/15

~ 700C 760C 700C / 72

35 MPa 35 MPa35 MPa



85

T/P91 (X10CrMoVNb9-1)A new steel ?

First new Power Plant Main steam col lector Power Plant

First application: 1992Start up: 1994

Main steam s stem

First application P91 1989Pipe delivered by Mannesmann

Filler metal deliver by Bhler (Thyssen)


Welding

Today operation time >180. 000 hours


86


-


87

The Development of Matching Filler Metals

Development of basicmaterial and welding

ConfirmationLong-term evaluation

Optimweld

Super 304 H, HR3C,

VM12

(347 HFG), Alloy 617

First use Base material ma er a

2007

2007

X10CrWMoVNb9-2 (P92)

7CrMoVTiB10-10 (P24)

X11CrMoWVNb9-1-1 (E911)

(1997) 2007

2000

2000

-

WB36

X20CrMoV12-1

14MoV6-3

1970

1965

1960

n. e.

10CrMo9-10

13CrMo4-4

15Mo3

1940

1940

1930

n. e.

n. e.

. .



88/

Working in Partnership

TNO

Siempelkamp P

a zg

Forschun

BWI

(Netherlands Organisation

for Applied Scientific Research)

res

Materialpr

Universit

Stahlinstitut VDEh(Verein deutscher Eisenhttenleute)

FDBR(Fachverband Dampfkessel-,

Behlter- und Rohrleitungsbau)

Institut fr W

Technische Univ

Fraunhofer InInstitut fr Fertigungs-technik (Universitt Graz/A)

VALLOUREC & MANNESMANN

TUBES



89/

-150

Inconel 617

100

E 911 / P 92

X8CrNiMoNbV16-13

50 P 22P 91

X3CrNiMoN17-13

0

X20CrMoV12-1X6CrNi18-11

Ni-base alloysaustenite

ferrite

500 550 600 650 700 750

Temperature [C]


- -for superheaters and reheaters in fossil fired powe


90

X10CrMoVNb 9-1 min. 0,08 8,0 770 C

after PWHT at 760 C (1,400 F) / 2 h;

YS

MPa KSi

TS

MPa KSi

Elongation

%

530 (77) 620 (90) 17


Requirements for P 91 all weld metal


92

Weldingprocess

Type

[mm]C Si Mn Cr Mo Ni V

Chemical composition; wire and all weld metal [wt-%]

SMAW Thermanit Chromo 9 V 3,2 0,09 0,23 0,65 9,1 1,0 0,76 0,2

GTAW Thermanit MTS 3 2,4 0,09 0,15 0,43 9,2 1,0 0,75 0,2

Thermanit MTS 3flux: Marathon 543

, , , , , , , ,

Mechanical propert ies at + 20C after PWHT at 760C/2h

process

Type[mm]

[MPa)

[MPa]

[%]

SMAW Thermanit Chromo 9 V 3,2 621 729 19,4 6

, ,

SAWThermanit MTS 3flux: Marathon 543

3,0 581 738 20,0 6


em ca compos on an mec an ca properof SMAW, GTAW and SAW filler metals for P91


93

Chemical composition [weight-% ]

Weld

metal

C Si Mn Cr Mo Ni Nb V

No. 1 0,10 0,26 0,68 9,39 1,05 0,39 0,055 0,21

No. 2 0,10 0,25 0,64 9,05 1,05 0,76 0,054 0,20

Ni: 0,76%

CV

N[J]

Ni: 0,39%

0 5 10 15 20-5Test temperature [C]


n uence o e -con en o e oug nessThyssen Chromo 9 V


94

120

C Si Mn Cr Mo Ni Nb V0,10 0,16 0,51 9,20 1,03 0,76 0,07 0,22 0

100

60CVN

[J]

PWHT: 760C/2h

20

40

0,05 0,06 0,07 0,08

C-content [%]


Influence of the C-content to the toughnessof Thermanit MTS 3 / Marathon 543


95

0 1

0,12C- content [%]

0,08

3

0,04

,

anit

M

T

hon

54

3

0

0,02

Ther

Mara

w re , , , ,

Basicity acc. Boniszewski


Influence of the flux basicity to the C- burn- o


96

Temperature [C]

800

900

Ac1b= 810C

Austeni tising: 30 min/1050CPrior austenite grain s ize: ASTM 10 and 3

F + C

500

600A + C Au

F + C F

A+C

Ms

Ms M

s200

300

Mf

M

103 104 105 106

te

10 101 102

410 409 406 395 181 149409 409 409

10 100 1000

1 10 100

[min]

[h]Time

100001


Continous cooling tranformation-diagram of T / P 9


97

1000

800 760C

600

rature[C]

Heating rate80 - 120C/h

-

200

400

Te

mpe

250 - 300C

< cool

slow

cooling rate

020 - 100C

preheating necessary cooling down after welding

Timeandsoaking

or soa ng


; ea con ro ur ng we ng an - co


98/

100720

SMAW: Thermanit Chromo 9 V

60

80

J]

740

760

780

40CV

N

0

20

Holding time [h]


-

to the toughness of matching fil ler metal to P9


99

300SMAW: Thermanit Chromo 9 V; : 4,0 mm

280

V10]

240rdness

[H

220Ha

0 2 4 6 8 10 12 14

Holding time [h]

200


-

(temperature / time) on the hardness at + 20C


10

CVN [J] CVN

70

50

30

10

Toughness at + 20C in relation to the weld build

. . . .


a we me a or


10

P91; Control Preheat-, Interpass- and PWHT- Temperature



10

Endcrater cracks at SMA wecan be avoid by current slop

If not, grinding the end crate



10

Chemical composi tion all weld metal for P 91

C Si Mn P S Cr Mo Ni V

0.10 0.21 0.68 0.008 0.008 8.91 1.05 0.81 0.21

CVN (ISO

J

A4

%

TS

MPa

YS

MPaHeat treatment

ec an ca proper es a we me a a a er quenc ng emper ng:

127 / 124 / 206935481070 C / 30 min. +

118 / 121 / 237015481050 C / 30 min. +

760 C / 2 h

Welding parameter SMAW: El-: 4.0 mm; TPreheat = 200 C; TInterpass = 250 C; IS = 1


SMA weld metal Thyssen Chromo 9 V quenched + t


10

P91 root electrode for application where purging is not possibl

Without PWHT PWHT: 760C (different locations at the halfpipe)

T t lt t RT ft PWHT)2067 2068

Test results at RT after PWHT):Ys: 476 MPa; Ts: 663 MPa; Location of fracture: BMCVN: 40 / 35 / 38 J; Hardness: 254 HV10 max


P91- girth weld; root with Thermanit Chromo T91; verticawelded at Bechtel)


10

Thermanit Chromo T91

P 91: SMA - root we91: SMA root we



10

Filler metal for new i e and tube steels

for USC power plants; P92 and VM12-S



10

Materials for Headers

X20CrMoV11-1-

X11CrMoWVNb9-1-1 (P X10CrWMoVNb9-2 (P92Alloy 617

Selection of Creep Rupture Strength for PipinMaterials

300N/mm

2 Mean Creep Rupture Strength 100.000 h

200

250

- P 92

Al loy 617

Al loy 6

50

100


480 500 520 540 560 580 600 620 640 6

Temperature in C

0


10

735 C

Temperature Limits of Headers and Piping Systems used byHPE under the Aspects of Design Temperatures according EN

12952

625 C*

(* 635 C HR-Systems)

600 C

X10CrWMoVNb9-2

Alloy 617

580 C

X11CrMoWVNb9-1-1

E911

(P92)Considering th

properties:

Strengths

Oxidation in SteCreep Strength

High-Temperatu


X10CrMoVNb9-1


10

Matching fi ller metals (FM) for thebase metals (BM) P91, P92 and VM12-SHC

BM FM C Si Mn Cr Mo Ni V Nb W

Chemical composi tion all weld metal

P91

, , , , , , , ,

FCW 0,10 0,19 0,68 8,85 1,00 0,43 0,21 0,041

GTAW 0,098 0,25 0,74 8,81 0,99 0,46 0,19 0,061

* , , , , , , , ,

P92

SMAW 0,107 0,23 0,76 8,58 0,45 0,60 0,19 0,044 1,69 0,0

FCW 0,092 0,17 0,86 9,31 0,46 0,57 0,21 0,046 1,47 0,0

, , , , , , , , , ,

SAW* 0,095 0,24 0,81 8,50 0,44 0,53 0,17 0,067 1,74 0,0

VM12-SHCSMAW 0,126 0,26 0,63 11,32 0,31 0,83 0,22 0,058 1,39 0,0


, , , , , , , , , ,

* Flux BB 910 / Marathon 543


11

Matching fil ler metals (FM) for the

base metals (BM) P91, P92 and VM12-SHC

BM FM

mmPWHTC/h

YSMPa

TSMPa

Elongation%

CVN(ISO-

Mechanical properties all weld metal at RT

P91

, ,

FCW 1,2 760/2 633 761 19,0 36 / 41

GTAW 2,4 760/2 682 795 16,4 170 / 171

* , ,

P92

SMAW 4,0 760/2 647 774 17,8 46 / 47

FCW 1,2 760/4 637 743 18,2 43 / 50

, ,

SAW* 3,2 760/4 638 761 19,6 70 / 77

VM12-SHCSMAW 4,0 770/2 610 792 14,4 42 / 46


, ,

* Flux BB 910 / Marathon 543


11

Base

metalHAZ

Weld

metalHAZ


P911 / SMAW Thermanit MTS 616; 650C, 70 MPa, 42


11

265l

ine

line

-

235

245

[HV10]

fusion

fusion

70 MPa, 650C, 4295 h

reface

205

215

ardn

ess

fractu

165

175

185

Base metal Weld metalHAZ HAZ

Hardness rofiles of cree sam les

0 10 20 30 40 50 60 70 80

Length of specimen [mm]


welded joint (P92 / Thermanit MTS 616)


11

Requirement of t ime limit between welding and PWHT of

martensitic steels P91, P92 und VM12-SHC:

NO, if adherence of the fol lowing conditions :

stress free storage and stress free transport

Avoidance of extreme environmental influence hi h air mois

air atmosphere)

weldments for PWH-treatment without time climate.



11

Power Plant

Main influence:

Pre heating temperature

Interpass temperature

Heat input

Weld built up

Thickness of layers

Bevel preperation

Geometry of joint

Weld process

Welding parameter

-

demands most exact settings and highly-qualified

staff.

Parameters


A good weld metal on its own does not guarantee a sound joint , if you do not care for


11

Conclusions

- Filler metals for P91 have been developed sometime now . Als-

new power plants in Germany, Europe and also in other co

-

especially CVN values have been discussed.

- The developed filler metals ful fil l the required creep strength at

tem erature, which can onl be uaranteed with conservative

consuming creep rupture tests.



11

Welding of P91

THANK YOUBohler Weldin Grou India Pvt. Ltd

B 201,Universal Business ParkOff Chandivili Farm Road, Sakinaka

Mumbai 400 072;India

Tel: 022 2857 4448/4458

E-mail: [email protected]



11

Welding of P91 matWelding of P91 mat

KOBE STEEL, LTD.Welding Business

Technical Development Dept.


11

Transition of steam conditionTransition of steam condition

for power generationfor power generation

Service starting yearService starting year

Steam PressureSteam Pressure

(16.6)(16.6)

(24.1)(24.1)

450C450C

483C483C485C485C

538C (1,000F)538C (1,000F)

566C (1,050F)566C (1,050F)

(31.0)(31.0)Steam TemperatureSteam Temperature

55

1010

1515

2020

2525

600600

550550

500500

450450

400400

SteamTemperature

(

SteamTemperature

())

SteamPressure(

SteamPressure(M

Pa

M

Pa))

(4.1)(4.1)

5555 6060 6565 7070 9090 99

3030

~

~

593C (1,100593C (1,100

HekinanHekinan

TechibanaTechibana--Bay No.1Bay No.1610C (1,130F)610C (1,130F)

Higher efficiency


11

Transit ion of heatTransit ion of heat--resistant lowresistant low--alloy steel for poweralloy steel for power

boilers in conjunct ion with improvement of creepboilers in conjunction with improvement of creep

rupture strengthrupture strength

2.25Cr-1Mo 2.25Cr-1.5WVNb

ASME T22 ASME T23

9Cr-1MoVNb 9Cr-0.5Mo-1.

12Cr-0.5Mo-2W

ASME T91 ASME T9

ASME T1


12

Coefficient of thermal expanCoefficient of thermal expan

cenothmaenon

Temperature oC)


12

Development of Steels for Power GenerDevelopment of Steels for Power Genera

P22(2.25Cr-1Mo) P91

(9Cr-1Mo-V-Nb

Condition : TemperaturMax. serviceInner diame


12

KOBELCO welding consumables for heat resistance loKOBELCO welding consumables for heat resistance lo

ACUS-12CRS/PF-200S

DCUS-12CRSD/PF-200S(D)

AC/DC

CR-12S

P/T92

P/T122

ACUS-90B9/PF-200S

DCUS-90B9/PF-90B9

AC/DC:US-9Cb/PF-200S

AC/DC

CM-96B9AC/DC

CM-9Cb

P/T91

SAW

(Wire/Flux)SMAWSteel type


12

B9 grade for P91 SteelB9 grade for P91 Steel

Mn+Ni: Max.1.50wt.%PWHT: 7451576015 AWS A5.5-2006AWS A5.23-2007

AWS A5.2


12


12

Chemical Composition of deposited mTrade

DesignationProcess

AWS B9 00.989.110.520.700.240.10TG-S90B9GTAW00.928.800.460.820.200.09

PF-200S

/US-90B9SAW

01.019.200.450.770.260.10CM-96B9SMAWMoCrNiMnSiC

Mechanical Properties ofPWHT

Condition

Trade

DesignationProcess

---Min.585Min.415ASME Gr.91

2228097067602hrTG-S90B9GTAW1116925577604hrPF-200S

/US-90B9SAW

62J743MPa603MPa7604hrCM-96B9SMAWvE20T.S.0.2%Y.S

Welding Consumables of B9 grade for ASME GWelding Consumables of B9 grade for ASME G

C.R.S.600 1000hr Creep Rupture StrengthC.R.S. of Gr.91 is estimated from PVP2006-ICPVT11-93350


12

Relationship betweenRelationship between

PWHT condition and creep rupture properties of CMPWHT condit ion and creep rupture properties of CM--96B996B9

:550 :600 650 : Creep rupture test result of deposited metalDotted linePredicted creep rupture strength for Welding Joints (T91/P91Solid lineCreep rupture strength forT91/P91Base Metal (NIMS CREEP DA

PWHT760 2hr PWHT

Max. PWHT Temperature of -B9 : 780Max. PHWT Temperature of -9Cb: 760

Stress(MPa

)

Stress(MPa

)

Rupture time (h) Rupt


12

Welding Consumables for ASME Gr.91 SteelWelding Consumables for ASME Gr.91 Steel

Chemical Composition of deposited Trade

DesignationProcess

0.988.860.381.290.270.08MG-S9CbGMAW

0.908.970.680.990.160.07TG-S9CbGTAW

0.888.310.551.580.120.06PF-200S

/US-9CbSAW

1.069.110.941.510.310.06CM-9CbSMAW

MoCrNiMnSiC

1206985687408hrMG-S9CbGMAW

Mechanical Properties ofPWHTCondition

TradeDesignation

Process

---Min.585Min.415ASME Gr.91

>2607777017408hrTG-S9CbGTAW957095847408hrPF-200S

/US-9CbSAW

129J756MPa593MPa7505hrCM-9CbSMAWvE20T.S.0.2%Y.S

C.R.S.600 1000hr Creep Rupture StrengthC.R.S. of Gr.91 is estimated from PVP2006-ICPVT11-93350


12

200300400500600700800900

1000

640 670 700 730 760 790 820Temperature of PWHT ) 4h

0.2%YS.&TS.(MPa)

WM :A (Mn+Ni=2 .49 )

A335 Gr.P91TS.585MPa

A335 Gr.P91

0.2%YS.415MPa

Ac1A

0.

T

Ac1B

Difference between B9 an- PWHT temperature vs. TS Y

-9Cb Mn+Ni = 2.49%


12

0

50100

150200

640 670 700 730 760 790 820Tempe r a tu re o f PWH T ) 4

vEJ -9Cb (Mn+Ni=2.49%)

Ac1A Ac1B

-B9 (Mn+NAverage of 3 piece

Difference between B9 an- PWHT temperature vs. IV-


13

Ac1

Ac3

A

B

C

Rate of =AB/AC100

Dilatation

(m)

Temperature () 20406080100

700 750 80Temperat

R

setaomao

Ac1 A Ac1 B

-9Cb(Mn+Ni=2.49%)

Transformation rate while h

Difference between B9 an- PWHT temperature vs. transformat


13

0

40

80

0 300 600 900Tem perature )

Daoum

-9Cb Mn+Ni=2.49%)Top temperature760Ac1+30

Ac1Heating

Cooling

Changes of dilation during cooling process should be

Cooling rate 2/minHolding time at the top tem

400Freshmartensite 0

40

80

0 30Temp

Diaoum)

-B9 MnTop temperature

Difference between B9 an- -B9 vs. -9Cb on temperature-dilation


13

PWHT temperature760Ac1+30

-9Cb Mn+Ni2.49%)

Tempered martensite +

Fresh martensite

-B9 Mn+

PWHT t820

Tempered ma

Difference between B9 an- -B9 vs. -9Cb on microstructur


13

10

100

1000

10000

100000

600 700 800 900

PWHT Temp.)4H

CretmetoruueH)

Stress:

147MPa

Ac1

A

Stress:108MPa

10

100

1000

10000

100000

600 70

PWHT

CretmetoruueH)

Str

147M

Difference between B9 an- PWHT temperature vs. Creep rupture-9Cb -B9


13

Examinations of proper PWHProper PWHT temperature versus Ac1

Ac1 of -9Cb 733Ac1 of B9 785

Adequate weld

may not b

PWHT temp. shouldnt be determined fro

Proper PWHT temp. versus mechanical

Proper PWHT temp. versus precipitation

Parti

Creep rupt


13

10

100

1000

27.0 29.0 31.0 33.0

T.P.=(273+T)(Logt+31.2)/1000

Stress

MPa

Min. Creep rupture strength records of

Gr.91 steel weld joints

(According to Report of PVP2006)

-9Cb Mn+Ni=2.49% Ac1:733

Max

T:Test temperature () tTime to rupture

Creep rupture strength of -9Gr.91 weld joints


13

10

100

1000

27.0 29.0 31.0 33.0

T.P.=(273+T)(Logt+31.2)/1000

StressM

Pa

Min. Creep rupture strength records of

Gr.91 steel weld joints

(According to Report of PVP2006)

-B9 Mn+Ni=1.38% Ac1:785

T:Test temperature () tTime to rupture

15

Max

Creep rupture strength of B9weld joints


13

Examinations of proper PWH

Creep rupture performance reduces steep

For weld metal B, when PWHT temp. exceed

PWHT temp. should be lower than its A

No steep descent in the creep rupture strengthCreep rupture strength is equal to or high than

For -9Cb, even PWHT temp. is 760 exceed

Precipitation should be investigated to confirm

As WeldFresh martensite

After PWHTempered mart

Microstructure

schematicM23C6

MX

PWHT


13

670

790

TEM micrographs of -9Cb for inPWHT temp.


13

Analysis results of extractedof -9Cb

0.00

0.25

0.50

0.75

1.00

650 700 750 800 850PWHT temperature ( )

Cr

0.00

0.05

0.10

0.15

650 700

PWHT

0.01

0.02

0.03

0.04

650 700

PWHT

0.04

0.06

0.08

0.10

650 700 750 800 850

PWHT temperature ( )

V

Extractedresidues(wt

%)

Extractedresidues(wt

%)

Extractedres

idues(wt%)

Extractedres

idues(wt%)

Ac1 A

AAc1


14

Tips for Successful WeldTips for Successful Weld

P91 SteelP91 Steel1. Remedies to cold or delayed c

Preheating and Inter-pass temp. to 250Reduction of Cooling Rate for reduction of ten

strength of weld metal.

Postweld heating by 250-300oC for 30-6Conduction before PWHT

For removing the diffusible hydrogen

Re-Drying before use welding consumaFor SMAW and SAW flux

SMAW: 350oC for 1hour

SAW flux: 250oC for 1hour


14


P91 SteelP91 Steel2. Preventing hot or solidification

Selection of Optimum Welding ConditioExcessively high welding currents should be a


14


P91 SteelP91 Steel3. Proper PWHT temperature

710-760oC for -9Cb710-800oC for B9


14

Thank you for your atteThank you for your atte


14

Measuring methods and resuMethods

Measuring quantity Longitudinal

strain

Diametrical

strain

Measuring device LVDT LED beam

Atmosphere N2 High-vacuum

Heating rate 10/s (RT-6005/m i n

Receiving

light

Test specimen

Displacement

detector

Probe

MethodMeasurement oflongitudinal strain by LVDT

Test

specimen

Method Measurediametrical strain by


14

-9Cb

(Mn+Ni=2.49%)696 733

-B9

(Mn+Ni=1.38%)758 785

Carbon steel 699 732Remarks

Oxide film

generated

Oxide film did

the specim

Measuring methods and resuMethods

Measuring quantity Longitudinalstrain

Diametricalstrain

Measuring device LVDT LED beam

Atmosphere N2 High-vacuum

Heating rate 10/s (RT-6005/m i n


14

A Lincoln Electric Company

Metrode Products Limited, UK

Dr. Raghvendra Srivastava


14

LINCOLN

METRODE

History

1963

2007


14

Location

Chertsey, SurreyUK

Near Heathrow Airport


14

Products


15

Product Range


15

Products

UKs leading manufacturer of alloyed welding consumables

Largest ranges of consumables from a single source


15

Sales Profile by Industry Sector

Offshore

Power

Petrochem

Standard Rangeinc R&M

Industries


15

Sales Profile by region

Europe & UK

Americas

Far East

Africa

China

Middle East

India/Pakistan

Presence


15

Dissimilar Welding of - P91 Steel


15

P91

Dissimilar combinations


15

Standards


15

CASE 1 P91 to Low Alloy Steel


15

CASE 1 AWS Recommendations


15

CASE 1 BS Recommendations


16

CASE 1 Industrial Practice


16

Critical Welding Parameters - P91/P22


16

PWHT - P91/P22A Compromise


16

Critical Joints - P91/P22

PWHT720/1-3hr


16

Recommendations - P91/Low Alloy


16

CASE 2 - P91 to Austenitic/higher alloys


16

CASE 2 - P91 / Austenitic/higher alloys


16

PWHT - P91/Austenitic


16

PWHT - P91/Austenitic

AsWelded


17

CASE 2Issues & Alternative Material P87


17

IssuesP91 /Austenitic/higher alloys

Microfissuring


17


Thermal Expansion


17


Carbon

Migration

Filler Metal Denuded Zone


17


CarbideFormation


17

New MaterialP87

P87

METRODE EPRI


17

P87Microfissuring

Elemental controlto eliminate

Microfissuring


17

P87Microfissuring

Microfissuring

Reduction


17

P87Thermal Expansion

Thermal Expansion

P87

7.5


17

P87Carbon Migration

P87 Ni-Base

1040C/2hrs + 980C/2hrs + 620C/4400hrs


18

P87Carbide Formation

Carbon Migration

Carbide formation


18

P87Carbide Formation

4500 hrs620 C


18

P87Mechanical Properties Ambient Temp.

P91 @ 68 (20C)

UTS = 85 Ksi (586)

YS = 60 Ksi (414)


18

P87Mechanical Properties Ambient Temp.


18

P87UTS vs. Temperature


18

P87YS vs. Temperature


18

P87Creep Properties

Gr.91 Min.Gr.22 Min. 304H Min.

P87


18

P87Creep Properties

100-5500 hrs, 677-732C

Failure: Base Metal


18

P87Welding Consumable


18

CASE 3 - P91 to P92

P91


19

Conclusions

P22(P11) /9CrMo

PWHT720/1-3hr

P91 +Austenitic/higher

Ni-Base (182)

P87

P91P91 +

P92

PWHT760/1-3hr


19

Critical Welding Parameters - P91/P22

BACK


19

Alstom

Indoctrination for the

Fabrication and Assembly of Gr

91 Material and Hardness Testi

Rev. 2, August 6, 2010


19

- - P 2

Alstom Grade 91 Indoctrination

The specifications and cautionary notes contathis indoctrination represent requirements tha

supplement those contained in the ASME BoilPressure Vessel Code Section I and Power Pip

These rules are necessary to ensure the satisfserviceability of any component fabricated by Alstom Power, Inc.


19

- - P 3


No welding of Grade 91 material shall take plathe fabricator has been indoctrinated to these

requirements.

Training shall be conducted by Alstom personpresented to the fabricators management, suwelding engineers, welding instructors, and qpersonnel.

The fabricator shall train their welders to this sprior to the start of Grade 91 pressure part we


19

- - P 4


The fabricator shall include a hold point in the

Manufacturing Quality Plan (MQP) for First ArtInspection (FAI).

Alstom personnel shall witness the First ArticInspection (FAI) at the start of Grade 91 presswelding.


19

- - P 5


Thispresentationis to help you

understandtheimportance offollowingAlstoms

Standards 2-2004-10 toavoid suchweld failures.


19

- - P 6


What Alstom requires in the fabrication and assembly Grade 91 components.

Welders shall be qualified to ASME Section IX Minimum preheat for GTAW 300F (150C)

Minimum preheat all other processes 400F (20

Interpass temperature 750F (400C) maximum

Hydrogen bake welds over 16 mm thick and O115mm after welding is completed

I.D purge with 100% argon for at least 2 passe

Post-weld heat treatment 1350-1425F (730-775per inch of thickness, 30 minutes minimum

Hardness test results shall be documented

Records are maintained


19

- - P 7


Permitted Welding Processes GTAW - Gas Tungsten Arc Welding

SMAW - Shielded Metal Arc Welding

SAW - Submerged Arc Welding

GMAW/FCAW - Gas Metal Arc Welding/Flux Cored Arc Weldinpermitted for welding Grade 91 or attachments to Grade 91 wheAlstom. See Slides 11 and 12 for acceptable welding consuma

Welding consumables shall conform to ASME Code Section II PaEN Standards.

Actual material certifications are required for all electrodes & wirecertificates will be accepted.


19

- - P 8


Documents required to be reviewed by Alstomwelding

Fabricator/assembler shall submit Welding Procedure Spwith Procedure Qualification Records, which shall be sig

welding engineer. The PQR shall be signed by the NotifiePED and Competent Authority for IBR projects.

Fabricator/assembler shall follow the WPS for purging of100% Argon gas shall be used, no mixed gases permitted

Fabricator/assembler shall submit welding material contprocedure.

Fabricator/assembler shall submit post-weld heat treatinwhich includes heating and cooling rates.

Fabricator/assembler shall submit non-destructive testinprocedures.

Work shall not proceed until Alstom personnel has approdocuments.


20

- - P 9

Welders Performance Qualification

All welders shall have passed a weld test in accordanceCode Section IX, EN 287 or IBR as applicable. The weldbe witnessed by the Notified Body for PED and Competefor IBR projects.

Confirm that welders have been working within the initiaqualification. This shall be confirmed every six month oassigned to production welding for each process. If thewelder has not been engaged in welding in the past 3 momust be retested. Check continuity records.

Welders continuity records shall be the fabricators/asseresponsibility and shall be available for review by Alstom



20

- - P 10


BE CERTAIN THAT

YOUR

WELDERS ARECERTIFIED

FOR THE POSITIONTHEY

ARE WELDING.


20

- - P 11


Filler Metal

Filler metal permitted for welding Grade 91 to

for ASME and IBR Codes:

ER90S-B9- GTAW

E9015,16 or 18-B9- SMAW

ER90S-B9- GMAW

E91T1-B9- FCAW EB9- SAW


20

- - P 12


Filler Metal

Filler metal permitted for welding Grade 91 to for EN Standards:

W CrMo91 141-GTAW

E CrMo9 B 42 H5 111-SMAW

Cormet M91 (MCW) 131-GMAW

Metrode Supercore F91 137-FCAW

S CrMo91 12-SAW


20

- - P 13


Filler Metal for Welding Grade 91 to 91

All welding filler metal shall be purchased with the cnickel and manganese content not exceeding 1.2% a

nitrogen content shall be at least (0.5 x Aluminum c0.03)%.

Actual material chemistry certs for all Grade 91 conshall be submitted to Alstom personnel for review.

Any deviations from these requirements will requireapproval.

G Grade welding consumables are not acceptable


20

- - P 14

Procurement

Storage

Control



20

- - P 15


Welding Material Control System

Fabricator/Assembler shall have a documented proced

procurement/storage of filler metals. Purchase only welding electrodes that are approved by

Section II Part C or equivalent EN standards.

Purchase coated electrodes in sealed containers.

Store low hydrogen electrodes in a clean dry area.

Store open containers in stabilizing or portable ovens atemperature between 250F - 350F (120-175C).

Damaged or wet electrodes must be destroyed.


20

- - P 16


Welding Material Control System

Identify all production welds with their appropriate filler

Filler metal to correspond to pressure parts being welde

Dispense filler metal from a restricted and controlled are

Issue a functional portable storage oven to welders wheelectrodes.

One or two types of filler metal with the same suffix maya welder at a time. Example: GTAW/SMAW, suffix B9.

Unused electrodes shall be returned to the dispensing aof the work period.

All dispensed filler metal shall be documented in a log.


20

- - P 17


Eliminate poorhousekeepingof weld rodstubs on theshop floor and

open box ofrods on beam.


20

- - P 18


Welding Preparations

All surfaces to be welded shall be free of anycontaminants (paint, loose rust, oil, grease, di

and moisture).

Grit blasting, if employed, shall be performed silica media.

For field welds, the welding area shall be proterain, wind, and other weather related elementwelding, inspection and post weld heat treatm

activities have been completed.


21

- - P 19


All welding machines shall be calibrated

Ground cables from welding machines shall b

directly to the part being welded. Pay close attwelding leads to prevent them from arcing agaGrade 91. Welding leads or electrical cords shrun across the Grade 91 materials.

A safe and preventative practice is to ensure w

leads, electrical cords, and lights, are up and oway, and secured with a non-conductive mate


21

- - P 20


Arc Strikes

It is imperative that all Arc Strikes be avoided.

If for any reason the base material is subjectedstrike, or accidentally welded upon, a NonconReport (NCR) shall be issued to Alstom immed

No further work shall be performed on the comuntil dispositioned by Alstom personnel.

It is generally advised that the base material athe work area should be wrapped with fire-retabarriers to avoid accidental arc strikes.


21

- - P 21


Fit-up Bridges

If bridges are used for fit-up, they shall be mad

Grade 91 material and welded with Grade 91 fi

Any weld areas associated with these bridgescontained within boundaries prescribed for prand post weld heat treatment.

All bridges that are tack welded on the OD of tshall be inspected with either MT or PT after twelds have been removed.


21

- - P 22


Preheating

Preheat shall be applied using electric resistance elemecontrolled, measured and monitored over the entire soadefined by the relevant code or 3 (75mm) on either sidewhichever is greater. Results of preheat shall be docum

Flame preheating may be used, provided the following cmet:

Only low temperature, neutral flame is permitted with a

with propane gas. Monitoring shall be provided at all t

At no time shall the metal temperature at any location e

1400F (760C). Cutting torches are prohibited.

The preheat temperature shall be a minimum of 300F (15gas tungsten arc welding process and shall be a minimu(205C) for all other processes.


21

- - P 23


Preheat maintenance

Preheat shall be maintained throughout the enwelding cycle, including tack welds and fit-up Preheat may only be interrupted provided all o

following conditions are met: A minimum weld material deposited in the weld g

3/8 (10mm) or 25% of the weld joint thickness, wgreater.

A hydrogen bake shall be performed immediately

A visual examination for cracks is performed prio

resuming welding. The required preheat is re-established prior to re

welding.

Results of preheat shall be documented.


21

- - P 24


Interpass Temperature

Interpass temperature shall not exceed 750F (

The interpass temperature shall be measured monitored at the last deposited weld bead of tjoint.

The interpass temperature shall be measured of temperature indicating crayons, optical pyrthermocouples with calibrated chart recorders

potentiometers or an equivalent method that dharm the base material or deposited weld met

Result of the interpass temperature shall bedocumented.


21

- - P 25


Fabrication of Complex Componen

Preheat segment or entire component to be we400F (205C), depending on quantity of joints be

welded. The completed welds shall be maintained at 20

until all welding on the entire component is com

Care shall be to minimize any loads to the combefore hydrogen bake or post weld heat treatm

been performed.

If post weld heat treatment is delayed for more hours, perform the hydrogen bake.


21

- - P 26


Suggested Welding Sequence (6 p

Preheat to 400F (205C) and weld joints 1, 2,

following the Welding Procedure Specificat Complete welds 1, 2, and 3.

Let cool to below 200F (95C) and post weldwelds 1, 2, and 3 prior to drilling.


21

- - P 27


Drilling of Component

Move header to drilling machine, mark and drill holes

Preheat to 400F (205C) and weld joints 4, 5, and 6 folWelding Procedure Specification.

Complete welds 4, 5, and 6.

Maintain welds 4, 5, and 6 at 200F (95C) after weldingpost weld heat treatment.


21

- - P 28


Continue Welding

Rotate header to 1G position to optimize welderaccess.

Preheat to 400F (205C) and weld joints 7, 8, and 9following the Welding Procedure Specification.


Maintain welds 7, 8, and 9 at 200F (95C) after welduntil post weld heat treatment.


22

- - P 29


Continue Welding

Rotate header to 1G position to optimize welderaccess.

Preheat to 400F (205C) and weld joints 10, 11, an

following the Welding Procedure Specification.


Maintain welds 10, 11, and 12 at 200F (95C) afterwelding and until post weld heat treatment.


22

- - P 30


Hydrogen Bake

Maintain entire component at 200F (95C) until post wheat treatment.

If post weld heat treatment is delayed for 8 hours or

more and 200F (95C) cannot be maintained, performhydrogen bake on the entire component, see figure slide 34.

If 200F (95C) has been maintained until PWHT, hydrbake is not required.


22

- - P 31


Hydrogen Bake

After all welds are completed on large components, or acompletion of a single weld, the welds shall be cooled ibelow 200F (95C) prior to hydrogen bake.

If it is not possible to perform post weld heat treatmenthours after the completion of the weld, a hydrogen bakeperformed on the weld joint. Tubes and pipes with the odiameter up to 4.5 (115 mm), inclusive, and wall thickn5/8 (16 mm) are exempt from hydrogen bake, see figur

Hydrogen bake shall NOT be interpreted as a post-weldtreatment.


22

- - P 32


Hydrogen Bake

Hydrogen bake shall be either by furnace or lo

heating. If localized heating is used, electric reelements shall be used as the heat source covinsulation.

The temperature shall be raised to 500-750F (2and held for one hour per inch of thickness, upmaximum of four hours, but in no case less tha

minutes and then allowed to cool in still air to temperature.


22

- - P 33

Hydrogen Bake

Hydrogen bake shall be monitored by thermococalibrated chart recorders, optical pyrometers otemperature indicating crayons.

Results of Hydrogen bake shall be documentedFigure 1, next slide.



22

- - P 34


Hydrogen Bake with PWHT at Later Time

0

200

400

600

800

1000

1200

1400

0 (1) Weldment may be cooled below 200F (95C) only if kept in clean dry environment.

Temperature-F

(1)

Figure 1

95C 95C

260-400C

Welding


22

- - P 35

Hydrogen Bake

Following any hydrogen bake, the componentkept dry until post weld heat treatment has beperformed.

Dry means that at no time shall the weld comecontact with liquids, including atmosphericcondensation (water). If this is not possible, tcomponent shall be maintained at a temperatu200F (95C).

Electric resistance elements shall be used to ecomponent remains dry.



22

- - P 36


External and Transport Loads

The weldment shall not be subjected to any aploads in the as-welded condition.

Do not use come-a-longs, air bags, wedges, hanything to move this material for fit-up.

Do not lift ground assembled parts into positiounit before post weld heat treatment has beenon the welds on the ground.

Care must be used to limit any stresses on wetransport prior to post-weld heat treatment


22

- - P 37


Post Weld Heat Treatment

If localized post weld heat treatment is utilized

resistance pads shall be wrapped completely entire circumference of the component and shcovered with insulation.

Direct flame heating for post weld heat treatmnot be permitted.

Calibrated recording devices shall be used to time at temperature during all PWHT, includingheating and cooling cycles. See Figure 2, nex


22

- - P 38

PWHT Immediately After Welding and Cooling

0

200

400

600

800

1000

1200

1400

TemperatureF

Figure 2

95C

730-775C

Welding


23

- - P 39



Post weld heat treatment shall consist of heating to theof 1350-1425F (730-775C) for one hour per inch of thickno case less than 30 minutes and allowed to cool in stil

All thermocouples shall be insulated from direct contacelectric resistance elements with thermocouple putty opads.

Refer to Alstom Standard 2-2004-10 for additional post treatment for Grade 91 material welded to other materia


23

- - P 40



The temperature of the weldment shall not exc(775C) for any reason during the Post Weld HeTreatment.

If the temperature exceeds 1425F (775C) for ana deviation from contract requirement shall beAlstom immediately.

No further work shall be performed on the comuntil dispositioned by Alstom personnel.


23

- - P 41



After the initial post weld heat treatment of oninch of thickness for the Grade 91, additional wmay be necessary to complete the component

If additional welding is required, such as seal socket welds or other attachment welds of .37or less, the weldment shall be post weld heat tthe temperature of 1350-1400F (730-760C) for a

of 30 minutes.


23

- - P 42



All P-15E Group No. 1, Grade 91 components tbeen welded shall not be subjected to any forcadjust or straighten before a post-weld heat tre

been completed. Headers that are completed and subject to stra

prior to tube-to-header welding, shall be givenPWHT at 1350-1400F (730-760C) for one hour pthickness, but in no case less then 30 minutes


23

- - P 43



The heating for aligning, adjusting shall be usin

resistance elements controlled by thermocoupare not permitted.

When heating is performed the metal temperatukept below 1425F (775C) and documented.

Any straightening operation shall be document


23

- - P 44


Weld Inspection

If radiography, ultrasonic testing, magnetic patesting or liquid penetrant testing is performedpost weld heat treatment, a hydrogen bake shperformed prior to performing any testing.

If liquid penetrant testing or ultrasonic testingperformed prior to post weld heat treatment, ttype method shall be used in lieu of water-solumethod.

It is important that all residue be removed fromcomponent after the testing is completed.


23

- - P 45


Weld Inspection

All root and final weld passes shall be 100% visually insp

As a minimum, 10% of all completed butt welds shall be eRT or UT.

100% of all completed attachment welds shall be examinPT.

Personnel performing NDT inspection shall be certified tor CP-189 or EN standards.

Acceptance criteria for defects shall be as outlined in ASEN standards.


23

- - P 46

Lifting Devices

Lifting devices used for Grade 91, such as slinchokers shall be fabricated from non-abrasive

nylon or mesh is acceptable. If wire rope slings are used, precaution shall b

prevent slippage and gouging of the material.

No lifting device or portion of a lifting device, slugs, are to be welded to any Grade 91 materia



23

- - P 47


Field Subassembly

For all Grade 91 welding performed on the grofield, the component shall receive a full post wtreatment in accordance with standard 2-2004-lifting the subassembly into place for final ass


23

- - P 48


After Painting and/or Prior to Shipp

All Grade 91 completed components shall be swith the words:

GRADE 91 MATERIAL

DO NOT STRIKE ARC

Use bright contrasting paint color for stencilin


24

- - P 49



24

- - P 50


Weld weave

bead shall

not exceed6 times core wire

diameter.


24

- - P 51


Weld weave

bead shall

not exceed

6 times core wire

diameter.


24

- - P 52

Proper support is always required.


24

- - P 53

Agenda

Hardness Presentation Outline

1st Topic Need for Hardness T

2nd Topic Precautions During T

3rd Topic Portable Devices Ev

4th Topic General Testing Pro

5th Topic Hardness Testing Su


24

- - P 54

Need for Hardness Testing

Grade 91 steel Very sensitive to processing Detailed fabrication procedures must be develo These procedures must be followed carefully

If Grade 91 processing sensitivity not recogni Failure of boiler components Possible injury and loss of life

Hardness testing Can be used to help assure procedures were fo

Nominally non-destructive Relatively inexpensive

Difficulties with Grade 91 Componen


24

- - P 55

Precautions During Testing

As with welding, anyone who thinks that hardtesting is simple has not attempted it

Hardness testing device usage Requires an understanding of operating princip

Device limitations

Ability to recognize device malfunctions Requires skill

Manual dexterity

Developed only through practice

Hardness Testing is not Simple


24

- - P 56


Surface preparation

Material sampled is very small, testing is very sensitsurface condition

Unrepresentative material must be removed

Paint and oxides

Decarburized layer

Hardness Testing is not Simple


24

- - P 57


Smoothness

Must be in accordance with procedure requireme

The lower the testing device load, the smoother tmust be

Some devices use very low loads and surfaces malmost shiny

Flatness Testing devices require at least two measuremen

area Test areas must be flat or measurements will be

varying depths

Hardness Testing is not Simple, (Contin


24

- - P 58

Portable Devices Evaluated

Pin Brinell

Based on standard Brinell machine principles Simple and robust, no electronics Relatively high load, minimizes surface condition ef Cannot be used on thin sections, fillet welds, or limi

areas Considered best device for general usage

MIC 10

Based on ultrasonic contact impedance principles Relatively low load, significantly influenced by surfa

Must be calibrated using calibration block having sacomposition, microstructure, and hardness as test a

Considered best where Pin Brinell cannot be used

Few Portable Devices Suitable for Boiler App


25

- - P 59


Equotip, TIME, and similar devices Based on Shore Schleroscope (indenter reboun

principles Relatively low load, significantly influenced by

condition

Significantly influenced by test area mass and Cannot be used on thin sections Considered unsuitable for boiler applications

Computest SC Based on standard Rockwell machine principle Uses very low load, significantly influenced by

condition Has large footprint, requires that welds be grouand limits access

Must be held very steady during operation to preadings and indenter damage

Considered unsuitable for boiler applications



25

- - P 60


TIV (Through the Indenter Viewing)

Based on standard Vickers machine principles

Relatively low load, significantly influenced by condition

Has large footprint, requires that welds be grouand limits access

Very difficult to hold steady on curved surfaces Considered unsuitable for boiler applications



25

- - P 61

General Testing Procedure

Select areas for test

Location dependent on component Number dependent on prior performance of vendor

issue being addressed

Rough grind

Welds only need to be smoothed to remove solidificand other gross irregularities

Base materials usually need 1 to 2 mm of metal remassure test areas are below decarburized layers

Depth of grinding must be reasonably uniform over enough to accommodate all anticipated hardness in

Final polish

Used to smooth, not reshape, test areas Grit size will depend on load of testing device

Total Effort must be Systematic and CarExecuted


25

- - P 62

General Testing Procedure

Take measurements at each test area

Two if using Pin Brinell

Maximum and minimum diameters of individual imust not differ by more than 0.1 mm

Brinell hardness values must not differ by more points at any test area

Five if using MIC 10

Running average used to evaluate individual tes

Individual test values that differ from running avemore than 30 HV points must be discarded

Total Effort must be Systematic and CarExecuted


25

- - P 63

Hardness Testing

Summary

Hardness testing is not simple

Testing is important to help assure safety and reliabilitycomponents

Testing must be performed by skilled personnel

Suitable devices must be used

Testing procedures must be followed

For hardness acceptance criteria, see Alstom Standard


25