Special features of the variation of structure and hardness of large-size quenched rolls from steel 9Kh2MF

Abstract

Nonequilibrium phases in the quenched surface layer of cold-rolled rolls decompose in tempering [1] providing the requisite hardness which is the most important parameter of the quality of these parts [2]. The temperature range and the kinetic parameters of the process of the decomposition of the phases are known. However, these characteristics depend considerably on the residual stresses which appear in heat treatment of specimens and parts. A study of a miniature laboratory specimen cannot allow for the effect of this factor on the decomposition of martensite and retained austenite in tempering. It is difficult to simulate the processes which occur in rapid induction heating of large parts for quenching. It has become possible to study the variation of the structure directly in the parts in the process of their heat treatment due to the advancement of the equipment and methods of x-ray diffraction analysis [3, 4].