Fracture toughness and fatigue crack growth properties of the base metal and weld metal of a type 304 stainless steel pipeline for LNG transmission

The fatigue crack growth rate and CTOD tests on type 304 stainless steel an d weld metal were studied over the temperature range -162 degreesC to room temperature. The girth weld metal specimens were fabricated using a combina tion of gas-tungsten-arc-welding and shielded-metal-arc-welding. The seam w eld joint was made by submerged are welding. Fracture toughness was evaluat ed through CTOD tests with three point bend specimens. The fatigue crack gr owth rate tests were conducted using compact tension specimens in accordanc e with ASTM E647. The CTOD values were affected by crack orientation with r espect to the rolling direction, but orientation had no influence on the fa tigue crack growth rates. The fatigue crack growth rates and the CTOD value s decreased with decreasing test temperature. (C) 2001 Elsevier Science Ltd . AU rights reserved.