一、前言 相变超塑性一般是指金属材料在低应力负荷状态进行内部相态变化时,材料的塑性会引起异常提高的现象。在特定试验条件下,可以使钢的延伸率达到百分之几百以上。因而近几年来,日益受到了国内外的重视。目前钢的相变超塑性的研究,主要是侧重于在较高温度进行反复相变过程的超塑性,即在αγ变态温度(A_1,A_3)区间上下进行 First, the preface Phase change superplasticity generally refers to the metal material under low stress load state of internal phase change, the plastic material will cause abnormal increase phenomenon. Under certain experimental conditions, the elongation of steel can reach several hundred percent or more. Therefore, in recent years, it has received more and more attention both at home and abroad. At present, the research on the phase transition superplasticity of steel is mainly focused on the superplasticity of the phase transformation process at a higher temperature, ie, up and down in the αγ metamorphic temperature range (A_1, A_3)