A STUDY OF REHEAT CRACKING WITH THE IMPLANT METHOD-ASSESSED THE REHEAT CRACKING SUSCEPTIBILITY OF 14MnMoNbB,BHW38,AND 15MnVNCu PRESSURE VESSEL STEELS

In this paper an implant reheat cracking test by stress relaxation was introduced and a comparison of the reheat cracking susceptibility of three pressure vessel steels, namely 14MnMoNbB,BHW38,and 15MnVNCu,was made.The study of suscep tibility was based on two rupture criterions:the minimum initial critical stress and the minimum rupture time shown on the "C"-shaped curve of reheat cracking.The test results revealed that the coarse grained overheated region of 14MnMoNbB steel was more susceptible to reheat embrittlement than that of BHW38 steel,while 15MnVNCu steel,being practically free from reheat cracking,was the one least susceptible.