Method of determining if an alloy article has any remaining working life

摘要

A method of determining if an alloy article (28) has any remaining working life comprises taking a sample from an alloy article (28) and removing all metal matrix material from the sample to leave the carbide particles. The carbide particles are analysed using x-ray diffraction to determine the ratio of the amount of the M23C6 carbide phase to the amount of the MC carbide phase. This ratio is compared with a database, containing the ratio of the amount of the M23C6 carbide phase to the amount of the MC carbide phase as a function of temperature of heat treatment and time of heat treatment, to determine the temperature of heat treatment and the time of heat treatment of the sample of the alloy article (28). This is compared with a database of heat treatment temperatures and associated heat treatment times corresponding to the full working life of the alloy article (28) to determine if the alloy article (28) has any remaining working life.