Method for estimating operating temperature of austenitic heat-resistant steel containing Cu (copper), method for estimating creep damage life of austenitic heat-resistant steel containing Cu, method for estimating operating temperature of austenitic heat-resistant steel tube containing Cu, and Cu Method for Estimating Creep Damage Life of Heat Transfer Tube Made of Austenitic Heat Resisting Steel Containing Carbon

摘要

In order to provide a creep damage life estimation method which is highly accurate and can easily estimate the operating temperature of an austenitic heat-resistant steel after long-term use or in a high temperature range, a hardened layer 2 is formed on a Cu-containing austenitic heat-resistant steel 5 by cold working, and the relationship between the amount of Cu-rich phase produced in the hardened layer 2 and the Larson-Miller parameter expressed as a function of operating temperature and operating time is determined in advance, after which a heat-resistant steel is subjected to cold working to form a hardened layer 2 on the surface of the heat-resistant steel prior to actual use, and then the amount of Cu-rich phase produced in the hardened layer 2 actually used at high temperature for a certain period of time is measured. The actual operating temperature is estimated from the relationship, determined in advance, between the amount of Cu-rich phase produced and the Larson-Miller parameter, the measured amount of Cu-rich phase actually produced, and the actual operating time. In addition, creep life can be estimated from the estimated operating temperature and actual operating stress, and the relationship, determined in advance, between the operating stress, operating temperature, and rupture time of the heat-resistant steel.