一、绪言用 AI 进行晶粒度调整的钢的奥氏体晶粒粗化温度因热处理而变化是人所共知的事实。而热处理对奥氏体晶粒粗化温度(以下简称晶粒粗化温度)的作用主要是根据AIN 的观点进行研究的,认为使 AIN 微细而均匀地弥散析出的热处理提高了晶粒粗化温度。不仅是 AIN,一般处于过饱和 I. INTRODUCTION It is well-known fact that the austenitic grain coarsening temperature of steel with grain size adjustment by AI changes due to heat treatment. However, the effect of heat treatment on austenite grain coarsening temperature (hereinafter referred to as grain coarsening temperature) is mainly based on the viewpoint of AIN. It is considered that the heat treatment for finely and uniformly dispersing AIN increases the grain coarsening temperature . Not only AIN, generally over-saturated