hobart self-shield wire presen

8/12/2019 Hobart Self-shield Wire Presen

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Self Shielded Flux Core Pipeline

Welding

ITW Hobart Brothers, Troy, OH


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Fundamentals of Self Shielded

FCAW


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Porosity Formation

Oxygen & Nitrogen

Carbon Monoxide (CO)

Nitrogen solubility in liquid iron (0.045%)

> solid iron (0.012%)


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Preventing Porosity

Generate sufficient shielding gas

Fix the Oxygen & Nitrogen through the

formation of stable oxides and nitrides


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Shielding Gas Generation

Flux ingredient (Carbonates & Fluorides)

CaCO3and MgCO3 decompose at 350 - 900C

and provide CO2

Metallic Oxide contributes to slag volume

Generates spatter during decomposition reaction

BaCO3& Li2CO3


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Shielding Gas Generation

Fluorides produce shielding gas & slag

Shielding gas produced through either

vaporization or dissociation of fluorides

CaF2used to scavenge O2, N, H2and reduce

sulfur & phosphorous

LiF2reduces nitrogen


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De-oxidation and De-nitriding

Al, Ti, Zr, Mn, Si, Mg


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Stub Loss


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Parameters F/S 81N1, 5/64" E7010, 3/16"

A. Wire/Electrode Unit Cost 1.00 1.00

B. Deposit Efficiency 75% 50%

C. Labour Cost $/hr 10 10

D. Deposition Rate lbs/hr 4.10 3.50E. Operating Factor 50% 30%

F. Material Cost Unit/lb = A/B/(1-H) 1.40 2.67

G. Labour Cost $/lb = C*((1/D)/E) 4.88 9.52

H. Stub Loss/ Waste 5% 25%

Total Unit Cost Per Lb 6.28 12.19

Self Shielded FCAW vs SMAW


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New Generation

Self Shielded Wires

Low Spatter Level

Excellent Slag Detachability

Excellent Properties

Improved

Quality

Productivity

Overall Fabrication Cost


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E71T8-Ni1 in market

Slag


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New Generation Wire

NO SLAG


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E71T8-Ni1 in Market

Large and high

spatter level


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New Generation Wire

Small and low

spatter level


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Quantitative Spatter Generation

Comparison

0

5

10

15

20

25

%

SpatterGene

rated

200 A 250 A

Current

a

a

b

c b c

a - Current Wire

b,c - New Wire


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Recommendations

X65, X70 E71T8 - K6 FS 71K6

X65, X70: E71T8 - Ni1 FS 81N1

X80: E81T8 - Ni2 FS 81N2


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CVN Transition Curve

050

100

150

200

250300

350

400

450

-120 -100 -80 -60 -40 -20 0

Testing Temperature (F)

C

VNToughness(Ft-Lbs)


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Historical Tensile Strength Data

500005250055000

575006000062500

650006750070000

72500

7500077500

80000

Samples

T

ensileStrength(psi)


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Historical Impact Toughness

0

50

100

150

200

250

300350

400

450

500

Samples

Avg.C

VNValues@-40F(ft-lbs)


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China Pipeline Bureau

State owned Company responsible for oil and gaspipeline construction in China as well as overseas.

Used E6010 (EN) for root run and Self ShieldedFCAW (EN) for remaining passes - processdeveloped in late 80s


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West East Pipeline Project

4000 km (2500 miles) main pipeline to transport gas from

Xinjiang gas field, North-West China to Shanghai, East

coast of China.

API 5LX-70, 67 Joules impact, 1 meter diameter, 15 to

25mm wall thickness, 12lb of weld metal per joint.


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West East Pipeline Project

China Pipeline Bureau welding X-70 Pipe for the first

time.

New wires excellent CVN impact toughness exceeded

requirements and was the first wire to be qualified for the

project !!!

New wire preferred due to low spatter level and easy slag

removal over competitive wire !!!

China welders complete approximately 250 joints per day

for a 50 man welding crew.


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Shanghai


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China Pipeline


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China Pipeline


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China Pipeline

ITW Companies supplied over 1000 tons of Self Shielded Flux


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Shanghai

ITW Companies supplied over 1000 tons of Self Shielded Flux

Core Wire in 2002 !!!

hobart self-shield wire presen

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