Resistance of Welds to Sour Gas Environments

Sour Gas Testing – NACE TM0177 Test Levels II and III, Method A, Solution A, Applied Stress = 100% YS, Material Condition: All Weld Metal, As Welded

Heat Yield Strength (ksi) Coupling Result*
1 62 Coupled to Carbon Steel

Pass

NOT Coupled to Carbon Steel Pass
2 65 Coupled to Carbon Steel Pass
NOT Coupled to Carbon Steel Pass
3 63 Coupled to Carbon Steel Pass
NOT Coupled to Carbon Steel Pass

*Triplicate tests

Sour Gas Testing – NACE TM0198 Slow Strain Rate Tensile, Level VII, Test Environment: 25% NaCl, 500 psi (3.5 MPa) H2S + 500 psi (3.5 MPa) CO2, 401°F (205°C),
Material Condition: All Weld Metal, As Welded

Heat Environment* Time to Failure (h) Elongation (%) R.A. (%) Time to Failure Ratio Elongation Ratio R.A. Ratio Secondary Cracking
1 Air 33.3 47.9 63.5 - - - -
Level VII w/o S 32.1 46.2 61.2 0.96 0.96 0.96 No
2 Air 28.4 40.9 58.4 -   - - -
Level VII w/o S 26.5 38.2 55.7 0.93 0.93 0.95 No
3 Air 28.9 41.6 59.7 - - - -
Level VII w/o S 28.5 41.2 61.0 0.99 0.99 1.02 No

*Air – duplicate tests, Level VII w/o sulfur – triplicate tests
R.A.= Reduction of Area

Sour Gas Testing – NACE TM0198 Slow Strain Rate Tensile, Level VII, Test Environment: 25% NaCl, 500 psi (3.5 MPa) H2S + 500 psi (3.5 MPa) CO2,
Material Condition: All Weld Metal, As Welded, Heat 1

Test Temperature Environment* Time to Failure (h) Elongation (%) R.A. (%) Time to Failure Ratio Elongation Ratio R.A. Ratio Secondary Cracking
350°F (177°C)** Air 35.2 50.7 64.1 - - - -
Test Environ. + Sulfur 34.2 49.3 63.6 0.97 0.97 0.99 No
400°F (204°C)*** Air 35.8 51.5 63.1 - - - -
Test Environ. + Sulfur 34.5 49.6 56.1 0.96 0.96 0.89 No
500°F (260°C)*** Air 33.7 48.5 64.3 - - - -
Test Environment 33.7 48.6 61.0 1.0 1.0 0.95 No
550°F (288°C)** Air 34.1 49.1 65.7

-

-

- -
Test Environment 32.2 46.3 61.7 0.94 0.94 0.94 No

*Air – single test; Test Environment - **duplicate tests, ***triplicate tests

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