一、引言 近年来,对非平衡组织奥氏体化的研究表明,如果慢速加热、高速加热或在Ac_1~-～Ac_3~-点之间低温侧保温再加热到Ac_3~-稍上的温度,都会发生“组织遗传”。即使在较低的奥氏体化温度下,也会“复原”原始奥氏体晶粒的尺寸。只有在适宜的中速加热条件下才可避免组织遗传,鉴于工业生产中很难满足避免组织遗传要求的加热条件, I. INTRODUCTION In recent years, the research on the austenitization of non-equilibrium structure has shown that if slow heating, high-speed heating or reheating to a little above Ac_3 ~ - on the low temperature side between Ac_1 ~ - ~ Ac_3 ~ , Will occur “tissue genetic.” The original austenite grain size is “restored” even at lower austenitizing temperatures. Only in the appropriate medium-speed heating conditions can avoid the genetic heritage, in view of industrial production is difficult to meet the genetic requirements to avoid the heating conditions,