材料期刊网

目前的TRIP钢由于Mn、Si含量较低，室温条件下仅保留约10%的残余奥氏体，结果使变形过程中材料产生的相变诱发塑性量有限，不能满足一些要求产生更大相变诱发塑性场合的需要。研究表明：提高钢中Mn、Si含量并辅以适量其它合金元素(如铬和镍)是提高材料相变诱发塑性的有效途径。研究了Fe-17Mn-5Si-10Cr-4Ni合金在不同应变速率下的变形特性，结果表明：该合金经1100℃×1h正火处理后具有单相奥氏体组织，在1.1×10-4~5.5×10-2 s-1的应变速率内对其进行变形，真应力随真应变的增加而线性增大，且应力的增加与变形速率基本无关。变形速率为1.1×10-2 s-1时，材料的抗拉强度为750MPa，伸长率为49%。该合金在拉伸变形过程中产生如此大变形量的主要原因是发生了奥氏体→ε-M相变，应变速率增加，材料的相变诱发塑性量变化不大，但材料中的ε-M量却逐渐减少。

Conventional transformation induced-plasticity (TRIP) steels only contained about 10% retained austenite at room temperature due to low contents of Mn and Si, therefore, low TRIP effect during deformation greatly limited their applications in industry. Increasing the amount of alloying elements, especially Mn and Si, was proved to be a powerful method of increasing the TRIP effect of the materials. Accordingly, deformation characteristics of the Fe-17Mn-5Si-10Cr-4Ni alloy were investigated under different strain rate. It revealed that the alloy consisted of single austenite after normalizing at 1100℃ for 1h. Its true-stress linearly increased with an increase in true-strain under the strain rate between 1.1×10-4 s-1 and 5.5×10-2 s-1. Moreover, the alloy showed tensile strength of 750MPa and total elongation of 49% at the strain rate of 1.1×10-2 s-1. Great TRIP effect for the alloy was caused by phase transformation of austenite→ε-M, and the plasticity due to TRIP effect almost no changed, however the amount of ε-M decreased with an increase in strain rate.