A Study of the Susceptilility for HESCC and It's Evaluation in Duplex Stainless Steel Weldaments

Analytical Evaluation of Hydrocen Embrittlemanl Type SCC and It's Mechanism in Duplexs Stainless Steel Weldments

Abstract

In this paper the authers discussed the effect of microstructure and residual stress on the susceptibility to HESCC in TIG and EBW duplex stainless steel weld metals. It was found that weld metal has a remarkable susceptibility to HESCC than base metal because of the ferrite content increasing in weld metal and the discontinuous precipitation of austenitic phase in ferritic phase in TIG and EBW weld metal, which results in the decreasing of keying effect of austenitic phase on crack propagation. Crack growth rate in EBW weld metal was found to be faster than that in TIG weld metal, although their threshold stresses were almost the same. In addition to that, the existence of residual stress increased the susceptibility to HESCC in welded joint, especially in the welded joint of cold worked material.