Abstract
Resistance testing of steel to Sulfide Stress Cracking (SSC) can be performed according to the four methods given in NACE standard TM0177. However, for SSC testing of low alloyed line pipe steel for longitudinally submerged-arc welded (SAWL) large-diameter pipes of a grade up to X65 it is well established to conduct four-point bend tests according to the new NACE TM0316 standard on machined test specimens with reduced thickness. SSC testing was performed using transverse full-size four-point bend specimens with a thickness up to 35 mm, machined from base material and longitudinal weld, at loads up to 90 % of the actual yield strength of the pipe material. Finite element simulations have been made in order to analyze the stress distribution in the full-size four-point bend specimen under the high load present during the test.
The NACE TM0177 Method D “Double Cantilever Beam” (DCB) corrosion test is frequently used for the determination of the fracture toughness of higher strength steels such as Oil Country Tubular Goods (OCTG) in sour environments, which is represented by the KIssc value. In this study DCB testing was performed on X52 SAWL line pipe steel and the results are reported with regard to the requirements of the test method.
