High-temperature damage evaluation method for austenitic heat-resistant steel

摘要

PURPOSE:To evaluate a degree of damage of austenitic heat resistant steel in a shorter time than a breaking test with the same precision as it. CONSTITUTION:In a high temperature damage evaluation method of austenitic heat resistant steel, surfaces of mechanical component are polished, etched, metal metal structure is observed with a replica method or a direct observation method. Minute cavities produced in a grain boundary of certain area of the observed metal structure and length in the direction of the grain boundary of grain boundary deposit are measured. Said individual measurement values are added, a total value of the minute cavities produced in the certain area and the length of the grain boundary deposit is divided by the certain area or another total value of the length of the grain boundary in the certain area, and a grain boundary damage linear density and a grain boundary damage rate are found. Said measurement values are fit in a relative chart of the grain boundary damage linear density previously found in a laboratory or the grain boundary damage rate and a lifetime consumption rate for the purpose of obtaining the lifetime consumption rate of heat resistant steel.