Correlation for Method of Various Weld Cracking

Abstract

The relationships between various weld crack test methods were discussed at the 9th Commission meeting of I.I.W. This article evaluates crack determination methods for slit groove tests, H-type restraint cracking tests, TRC tests, RRC tests and Implant tests, and discusses the intensity of restraint and restraint stress influencing crack prevention preheating temperatures. Finally the relationships between various test methods are clarified concerning cracks caused in first layer. The results are as follows:
(1) The dependence of delayed cracks on colling speed (preheating), intensity of restraint, restraint stress and stress concentration will be explained using 80 kg/mm² high-strength steel.
(2) A nomograph was made up to clarify the relationships between the various test methods by relating the crack prevention preheating temperatures to critical restraint stress and critical intensity of stress in the first layer of 80kg/mm² high-strength steel.