Influence of preliminary heat treatment of heat resistant steels of pearlite class on the tendency of welded joints to fractures in reheating

The effect of the initial state of steels 12Kh1MF and 15Kh3m1F on their trend toward failure on second heating is studied. Annealed steel specimens have been subjected to various kinds of heat treatment. The dependence is established of the kinetics of dissolution of carbides in nonequilibrium welding heating on the properties of the alloys and the welding regime. As the activation energy of diffusion of the elements forming the carbide increases, the rate of solution sharply reduces, and the temperature of complete dissolution of the carbide increases. A reduction in the initial size of the carbide particles decreases the time of their dissolution and increases the probability of their complete dissolution under given welding conditions