Abstract
Influence of centerline segregations on hydrogen induced cracking for sour gas line pipe was investigated. As Crack Length Ratio (CLR) mainly depends on centerline segregation in the ease of well-controlled clean steel, it may discuss CLR with centerline segregations. Distribution of centerline segregation grains and P, Mn segregation ratio are represented by the experimental formulae for each casting condition. As a result, effects of casting conditions, soaking conditions and pre-reduction conditions on CLR can be estimated qualitatively, using HIC sensitivity paramenter with those formulae. Estimated CLR corresponds fairly well to measured CLR for several heats.
