Metallurgical Study on the Reheat Cracking in the Weld Zone of Steel (Report 2)

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

Abstract

As the purpose that reheat cracking testing method of steel by the stress relaxation test is to be a much simpler and highly reproducible, the present study is check up on the testing condition for the reheat cracking test of steel by conducting an examination with the test specimen for the synthetic weld thermal cycle.
Also, the evaluating method of the sensitivity of steel to reheat cracking with the test specimen for the synthetic weld thermal cycle was discussed.
The results of the study 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 remakable. The sharper notches or slower heating rate lead to the liability of cracking. Consequently, it is necessary to make these factors being constant in Evaluating the sensitivity to reheat cracking.
2) As compared the results of the reheat cracking test with the test specimens for the synthetic HAZ and the weld reinforced test specimens, there was a good consensus between cracking phenomenon and cracking sensitivity of both test specimens.
3) The reheat cracking test with the test specimen for synthetic HAZ is simple and highly reproducible. Moreover, by use of amount of the plastic deformation (Δlp') at the time of occurrence of the cracking, it is possible to evaluate the sensitivity of steel to its cracking.