Method for Evaluating the Sensitivity of Steel to Reheat Cracking by the Synthetic Weld HAZ

Abstract

In order that the reheat cracking testing of steel by the stress relaxation test may be made in a much simpler and highly reproducible, the present study has probed into the testing conditions for the reheat cracking test of steel with the use of test specimens for the synthetic weld thermal cycle. Also, a method of evaluating sensitivity of steel to reheat cracking with the test specimen for the synthetic weld thermal cycle is also discussed.The results obtained are summarized as followes:(1) The effects of the notches in steel and the heating rate on the sensitivity of steel to reheat cracking are remarkable. The sharper notches or slower heating rate lead to the liability of cracking. Consequently, it is necessary to make these factors constant in evaluating the sensitivity to reheat cracking.(2) Comparison of the results of the reheat cracking test between the test specimens for the synthetic HAZ and the weld reinforced test specimens, shows good correspondense in the cracking phenomenon and cracking sensitivity between the two test specimens.(3) The reheat cracking test with the test specimen for synthetic HAZ is simple and highly reproducible. Moreover, from the amount of plastic deformation at the time of crack initiation, it is possible to evaluate the sensitivity of steel to cracking.