Characteristics of Sulfide Stress Corrosion Cracking of High Strength Pipeline Steel Weld

  • 발행 : 2004.04.01

초록

The sulfide stress corrosion cracking (SSCC) resistance of API X70 grade steel weldment has been studied using SSCC test in NACE TM-O177 method A. Also, microstructures and hardness distribution of weldment was investigated. The microstructure of SAW joint composed ferrite, pearlite and some MA constituent. Instead of hardening in CGHAZ, softening on the HAZ near base metal occurred. The low carbon TMCP type steel used for SAW showed softening behaviour in the HAZ adjacent to base metal, which was known to be closely related with the SOHIC (stress oriented hydrogen induced cracking). The SSC testing revealed that the API X70 SAW weld was suitable for sour service, satisfying the NACE requirements. By suppressing softening in the ICHAZ region, the SSCC resistance of low carbon TMCP steel welded joints could be more improved.

키워드

참고문헌

  1. R.A. Camerio, R.C. Ratnapuli, and V. F Cunba Lins, The influence of chemical composition and microstructure of 86 API linepipe steels on hydrogen induced cracking and sulfide stress corrosion cracking, Materials Science and Engineering A, 357, 104 (2003)
  2. L.W. Tsay, Y.C. Chen, and S.L.I. Chan, Sulfide stress corrosion cracking and fatigue crack growth of welded TMCP API 5L X65 pipe-line steel, International Journal of Fatigue, 23, 103 (2001)
  3. S. Endo, Sulfide stress corrosion cracking in welded joints of welded linepipes, ISIJ International, 34(2), 217 (1994)
  4. G.M. Omweg, Effects of welding parameters and H2S partial pressure on the susceptibility of welded HSLA steels to sulfide stress cracking, Welding Journal, June 2003, pp.136S- 144S
  5. ISO 3183-1 : Petroleum and natural gas industries-Steel pipe for pipelines-Technical delivery conditions-, Part 1 : Pipes of requirement class A, (1996)
  6. L.E.Collins, Microstructures of linepipe steels. Canadian Metallurgical Quarterly, 22(2). (1996)