EFFECT OF AUSTENITISING ON THE STRUCTURE AND PROPERTIES OF LOW-ALLOY Cr-Mo-V STEELS AFTER LONG-TERM OPERATION IN CREEP CONDITIONS FOR THE POWER INDUSTRY

The article concerns the revitalising heat treatment of components of the pressure part of power units operating under creep conditions. The possibilities of “recovering” the structure and functional properties similar to those of the initial state are shown on the example of elbows and straight sections made of 14MoV6-3 steel (13HMF), after long-term operation, significantly beyond the computational working time, with slightly diversified but significant exhaustion. It is possible by selecting the type and parameters of heat treatment depending on the structure class after operation and the corresponding degree of exhaustion. The effectiveness of revitalising heat treatment is shown, especially in relation to the recovery of impact resistance and creep resistance due to the obtained structure corresponding to the initial state. The defined limitation in the operation of revitalising heat treatment of materials after long-term operation in creep conditions is the structure after operation, in which the initiation of internal damages as a result of creep will be revealed.