304奥氏体不锈钢热诱发马氏体相变研究

Thermal-induced martensite transformation in 304 austenitic stainless steel

借助X射线衍射技术,研究了304奥氏体不锈钢热诱发马氏体相变倾向。结果表明:C、Mn、Cr和Ni接近标准规范下限,304不锈钢的稳定性急剧下降,致使液氮内冷却后接近1/3的奥氏体转变为α′或ε马氏体,室温拉伸即形成应变诱发ε和α′马氏体,而且较小的室温变形显著增大随后液氮内冷却的热诱发α′马氏体相变倾向,但随室温预应变增大快速形成应变诱发α′马氏体,致使随后在液氮内发生热诱发α′马氏体倾向下降。此外,研究表明ε马氏体的形成及消失与α′马氏体的累积量有关。

With the help of X-ray diffraction technique, thermal-induced martensite transformation in 304 austenitic stainless steel was investigated. The experimental results show that the lower alloying element contents of C, Mn, Cr and Ni, which approach to low limit of standard specification of AISI 304 steel, resulted in significantly decreasing in stability of 304 stainless steel, approximate third austenite transform to α＇- or ε-martensite after cooling to liquid nitrogen. During room temperature tensile tests, α＇- and ε-martensite formed in the steel with lower limit C, Mn, Cr and Ni content. Room prestrain leads to increase in final amount of α＇-martensite after cooling in liquid nitrogen. Moreover, the formation and disappearance of ε-martensite depend on accumulate amount of α＇ martensite.