一、绪言一般,金属材料的强度和韧性是两个互相矛盾的性能,但晶粒超细化处理是使强度和韧性能得到改善的一种手段。目前,可用许多方法获得超细晶粒,其中之一就是Grange等人发明的快速循环热处理法,既将钢快速加热到较低的奥氏体化温度,进行快速冷却,反复循环两次以上的超细化方法。这种方法的超细化程度受原始 I. INTRODUCTION Generally speaking, the strength and toughness of metal materials are two conflicting properties. However, the grain refinement treatment is a means to improve the strength and toughness. Currently, many methods are available to obtain ultrafine grains, one of which is the rapid cycle heat treatment invented by Grange et al., Which both rapidly raises the steel to a lower austenitizing temperature, performs rapid cooling, and recycles more than twice Superfine method. The degree of refinement of this method is influenced by the original