Carbide formation in the niobium-microalloyed 15Kh2MFA steel during heat treatment

Despite the results already achieved in this field of research, interest in the transformation phase of the 15Kh2MFA steels remains high, which is due, in the first place, to the long-term operation of important products manufactured from this steel and the need for evaluation of their service life. The stability of the carbide phases in steels of this type, alloyed with niobium, after undergoing various modes of basic and post-welding heat treatments, is reviewed. It is shown that an increase in the duration and temperature of post-welding tempering stabilizes the phase composition and, therefore, increases the stability of the structure during operation.