Stainless Europe

Grade

22-05

This grade complies with: Stainless Europe Material Safety Data Sheet n°1

(European Directive 2001/58/EC). European directive 2000/53/EC on end-of-life vehicles

and later modifications. NFA 36 711 standard “Stainless Steel intended for use

in contact with foodstuffs, products and beverages for human and animal consumption (non packaging steel).”

Elements C Si Mn Cr Ni Mo N

% 0.02 0.3 1.8 22.8 5.5 3.1 0.17

The principal features of 22-05 are: An excellent corrosion resistance, with a minimum PREN

value of 35,0 Twice as high yield strength as our grade 18-9 E (1.4301,

Type 304) Service temperature range: - 40 °C to 300 °C

Equipment and piping for the chemical industry, oil and gas industries and desalination plants

Heat exchangers

Forms: sheet, blank, coil, strip, tubeThicknesses: 0.6 - 7 mm ( >7 mm on demand)Width: up to 1500 mm (depends on thickness)Finishes: hot rolled, cold rolled

The grade 22-05 is a stainless steel of the austenitic-ferritic group, whose structure is composed of a mix of ferritic (α) and austenitic (γ) phases. The dual phase structure of the alloy makes it possible to obtain elevated yield strength values whilst still maintaining sufficient ductility. The hardening is indeed provided by the ferritic phase, whereas the austenitic lattice enables to preserve both ductility and toughness.

The mixed structure confers a good resistance to stress corrosion cracking to grade 22-05 and also makes it insensitive to intergranular corrosion. Its high chromium and molybdenum content makes it resistant against both pitting and uniform corrosion.

Continuous use of 22-05 at temperatures above 300 °C is not recommended for the following reasons: - between 350 and 550 °C: loss of ductility by embrittlement of the ferritic phase due to the formation of a so-called α’ phase, possibly accompanied by other embrittling phases; this is a classical phenomenon encountered with ferritic stainless steels, more commonly referred to as “475 °C embrittlement”.- between 600 and 950 °C: embrittling sigma phase precipitation, related to the high chromium and molybdenum content.

Applications

Product range

Metallurgical propertiesChemical Composition

General Characteristics

European designation

X2CrNiMoN22-5-3/1.4462 (1)

American designation

UNS S32205(1) According to EN10088-2.

Typical values

Duplex stainless steel

Microstructure of 22-05 (dark areas represent the ferritic phase)

Temperature °C

1000

900

800

700

600

500

400

3001 2 4 6 8 10 20 40 60

Time (minutes) 2 4 10 20Time (hours)

Sigma

475 °C

Cold rolled and annealed sheet.

In annealed conditionAccording EN 10002-1 (July 2001), test piece perpendicular to rolling direction.

Test piece:Length= 80 mm ( thickness < 3 mm).Length= 5,65 So (thickness ≥ 3 mm).

At high temperatures

Mechanical properties

Condition Rm(1)

(MPa)Rp0,2

(2)

(MPa)A(3)

(%) HRB

Cold Rolled* 840 620 29 98

Temperature 50°C 100°C 150°C 200°C 250°C

Rp0,2(MPa) ≥ 420 ≥ 360 ≥ 335 ≥ 315 ≥ 300

Rm(MPa) ≥ 640 ≥ 590 ≥ 570 ≥ 550 ≥ 540

* Typical values.1 MPa= 1 N/mm2.(1) Ultimate Tensile Strength (UTS). (2) Yield Strength (YS). (3) Elongation (A).

This grade is particularly recommended under severe corrosion conditions, where it can replace highly alloyed austenitic stainless steels.

Corrosion resistance

20

15

10

Physical Properties

21

20

19

18

17

16

15

0 200 400 600

22-05

304

Values given for information only

Uniform corrosion

Resistance of 22-05 according to chloride and fluoride content and pH

8

8

33

yes

*

*Thermal expansion 25% lower than that of 316, comparable with carbon steel

ρ

α

ρ

CCCCononononccccententententrrrration % Hation % Hation % Hation % H2 2 2 2 SOSOSOSO4444T° CT° CT° CT° C10101010 20202020

20202020

30303030

30303030

40404040

40404040

50505050

50505050

60606060 70707070 80808080 90909090 98989898

316 L317 L22-05

Limiting service conditions of 22-05 in sulphuric acid (maximum corrosion rate= 0,2 mm/year)

P

Chloride concentration (g/l)

Fluoride concentration (ppm)

1 5

0 400 1000 0 400 1000

pH

6

4

2

1

316L

UNS S32550

Ti/Ni

22-05

ρ

BendingFor thicknesses below 0,8 mm, a minimum bending radius of 0,5 x thickness is recommended. For heavier gauges, the bending radius must be at least 1,5 x thickness.

This grade can generally be used for forming applications. Since its yield strength is about double that of 1.4301, Type 304, the use of presses or section rolling equipment with suitable power is required. The aptitude for stretch forming is determined by the dome height of the Erichsen test, whereas the deep drawing ability is defined by the limiting drawing ration (LDR).

Forming

Gradedesignation

European designation

ASTM A240

Erichsen cup test*

(mm)

Limiting Drawing

Ratio* (LDR)

22-05 1.4462 UNS S32205 9.5 1.9-1.95

*Valid for 0.8 mm sheet

0.09

0.18

0.27

0.36

10 50 100

316 L22-05

Corrosion rate (mm/year)

0.5

1

1.5

2

2.5

3

3.5

Formic acid

Oxalic acid

Acetic acid

Corrosion rate (mm/year)

22-05316 L304 L

Limiting yield strength

20

40

60

80

100

20 °C 60 °C

316 L22-05

Pitting potential (mV/SCE)

316 L

22-05

0

10

20

0.1

0.2

0.3

0.4

0.5

0.6

0.7

316 L 22-05

60 °C

24 °C

Corrosion rate (mm/year)

400

800

1200

30 50 70 ° C

22-05

316 L

Maximum chloride content (ppm Cl )-

Resis

tanc

e of

22-

05 in

a c

aust

ic en

viro

nmen

t lo

aded

with

sul

phur

com

poun

ds a

t 170

°C (K

raft

ce

llulo

se p

rodu

ctio

n pr

oces

s)

Resis

tanc

e of

22-

05 in

acid

org

anic

envi

ronm

ents

Resis

tanc

e of

22-

05 in

the

NACE

TM

01

-77.

NaC

I 5%

+ C

H 3 C O

OH

0,5%

en

viro

nmen

t H2S

pre

ssur

e: 1

atm

osph

ere

at 2

5 °C

, pH 3

Resis

tanc

e of

22-

05 in

P20

5 (tr

ansp

orta

tion

of p

hosp

horic

acid

). M

axim

um c

hlor

ide

cont

ent a

ccor

ding

to te

mpa

erat

ure

(for

in

dust

rial a

cid) 5

4%P 20

5-H 2S

O4<

4%-F

<1

%-H

F<0,

2%

Stress corrosion crackingDue to its dual phase structure, 22-05 is hardly sensitive to stress corrosion cracking. It shows adequate resistance in acid gas environments (C02 + H2S).

Influ

ence

of t

empe

ratu

re o

n no

n-cr

ackin

g lim

iting

yie

ld s

tren

gth

afte

r 720

hou

rs, i

n NA

CE e

nviro

nmen

t TM

01-

77, p

H 2S: 1

bar

.

Pitting corrosionGiven its higher chromium, molybdenum and nitrogen content, our 22-05 exhibits very good resistance against pitting corrosion. Its performance is in fact superior to that of both 304L and 316L. The pitting corrosion resistance ranking of stainless steels is generally established by means of the PREN (Pitting Resistance Equivalent Number= %Cr+3,3*%Mo+16*%N) formula. 22-05’s value typically lies around 35,7 compared to 24,1 for the 1.4401, Type 316 grade or 18 for the 1.4301, Type 304 grade.

Crevice corrosion22-05 resists well to this type of corrosion characterized by the depassivation pH, which is measured by electrochemical methods. The lower the pH (acid), the higher the performance of the alloy. At 30 °C, the pH of 22-05 is about 1, whereas it lies around 1,8 for a molybdenum alloyed austenitic grade (316) or 3 for a ferritic grade (430).

Pitt

ing

pote

ntial

in a

erat

ed N

aCI 3

0 g/

I at

70°

C

Crev

ice c

orro

sion

resis

tanc

e :

depa

ssiv

atio

n pH

Criti

cal c

revi

ce te

mpe

ratu

re o

f INC

O ty

pe

spec

imen

s in

a 1

0% F

eCl 3,

6 H 2O

env

ironm

ent

Pitt

ing

pote

ntial

in a

erat

ed N

aCI 3

0 g/

I acc

ordi

ng to

tem

pera

ture

Intergranular corrosionDue to both its low carbon content and its dual phase structure, 22-05 resists well to intergranular corrosion.

Pitting potential (mV/SCE)

304 L

316 L

22-05

200

400 1000

500

316 L

22-05

Pitting potential (mV/SCE)

20 40 60 °C

Cl-(g/l)

(% Rp0,2)

17-4 Mn

22 - 05

316 316 316 316 LLLL

304304304304 LLLL

301301301301

430430430430

1111

2222

1,1,1,1,5555

2222,,,,5555

-

+

pHpHpHpH

Welding

Weldingprocess

No filler material With filler material

Shielding gasTypical thickness Thicknesses

Filler material

Rod Wire

Resistance: Spot, Seam < 2 mm

TIG < 1.5 mm > 0.5 mm Modified “4462”ER 22.09

Modified “4462”ER 22.09

Argon (1)Argon + Helium (1)

PLASMA < 1.5 mm > 0.5 mm Modified “4462”ER 22.09

Argon Argon + Helium

MIG > 0.8 mm Modified “4462”ER 22.09

Argon + 2 % CO2Argon + 2 % CO2 + Helium

S.A.W > 2 mm Modified “4462”ER 22.09

Electrode Repairs E 22.09

Laser < 5 mm Helium + Nitrogen (25%)

Heat treatment After cold forming, an annealing treatment of a couple of minutes at 1050 +/- 25°C, followed by air cooling restores the structure and eliminates internal stresses. After heat treatment, pickling followed by passivation must be carried out.

Heat treatment and finishingPickling By acid mix (20% HNO3 + 2% HF) at room temperature or at 60 °C .By sulphuric-nitric bath (10% H2SO4 + 0,5% HNO3) at room temperature or at 60 °C. Pickling pastes for welds.PassivationNitric acid bath (10 – 25 %) at 20 °C.Passivating pastes for welds.Size range

Head offi ceArcelorMittal ParisStainless Europe1-5 rue Luigi Cherubini93212 La Plaine Saint-Denis Cedex

InformationTel. : (33) 1 71 92 06 52Fax : (33) 1 71 92 07 97www.arcelormittal.com/stainlesseuropestainless.europe@arcelormittal.com

Width (mm)

1500

1250

1000

3.5

Thickness (mm)Hot Rolled HRAP 1DHot Rolled HRAP 1DHot Rolled HRAP 1DHot Rolled HRAP 1D Consult usConsult usConsult usConsult us

2 2,5 3 654 7 10

2000 Width (mm)

1500

1250

1000

Thickness (mm)Cold Rolled 2BCold Rolled 2BCold Rolled 2BCold Rolled 2B Consult usConsult usConsult usConsult us0,4 0,5 1 32 4 5

22-05 is an austenitic-ferritic alloy of which the chemical analysis and heat treatment have been optimized in order to obtain a ferrite content in the base metal of between 38 et 55 %. In the case of welding without filler material, local fusion followed by rapid cooling takes place. Primary solidification starts with the ferritic phase, while the too rapid cooling prevents the regression of the ferrite into austenite, which leads to ferrite contents up to 90 % in the case of welding without particular care. The structure of the HAZ (Heat Affected Zone), having also undergone the welding thermal cycle, will be enriched in ferrite too, compared to the initial structure. An excess of ferrite (above 75 %) reduces both corrosion resistance and ductility.

Recommendations: in all cases, welding energy should be sufficiently high (> 2,5 kJ/cm) in order to avoid too rapid cooling. The energy must not be too high (< 20 kJ/cm) however, in order to ensure sufficient cooling to avoid the risk of precipitation of intermetallic phases in turn. The use of a top/bottom shielding gas is recommended. Nitrogen must be added in the case of welding without filler metal or adapted to the filler metal in the other case. Pre- and post heating must be avoided.

Weld properties: the austenitic-ferritic structure of 22-05 (primary solidification of the ferritic phase) eliminates the risk of hot cracking. If welded under the wrong conditions, this alloy can become sensible to cold cracking. To avoid all risks, no hydrogenated gas must be used for the purpose of welding and all filler materials must be correctly dried (temperature above 250 °C in most cases). Post weld heat treatment is not required in any form. The welds must be mechanically or chemically descaled and subsequently passivated (decontaminated).

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Plates

Thickness 5 to 150mm3/16" to 6"

Width Up to 3300mmUp to 130"

Length Up to 12000mmUp to 472"

Consult Industeel for other sizes including 4100mm (161.4") wide plates and clad plates

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