奥氏体化温度对Fe-17Mn-0.05C钢组织和拉伸性能的影响

Effect of Austenitizing Temperature on the Microstructure and Tensile Properties of Fe-17Mn-0.05C Steel

对一种热轧态高锰减振结构钢进行不同温度的热处理,研究了奥氏体化温度对其组织和拉伸性能的影响.结果表明:在600℃条件下,逆转变得到的全奥氏体组织只发生回复过程,冷却时ε马氏体含量比热轧态高,此时的拉伸强度和加工硬化率也较大.当奥氏体化温度为800℃或更高时,奥氏体发生完全静态再结晶.原始奥氏体晶粒尺寸和ε马氏体含量随着温度的升高而增加,但钢的力学性能随之变差.在1 200℃下奥氏体化处理后,组织中ε马氏体板条十分细碎;在拉伸时由于奥氏体晶粒尺寸太大,实验钢发生了沿晶断裂.

The effect of austenitizing temperature （tA） on the microstructure and tensile properties for a hot-rolled high-Mn structure steel with excellent damping capacity after heat treatment with different tA has been investigated.The results show that when the tA is up to 600℃, the only recovery occurs in the reversed austenite,and the ε-martensite amount, tensile stress and work hardening rate of the treated steel are higher than those of the rolling state one.When the tA is over 800℃, the completely static recrystallization of austenite can be observed.Moreover, the austenite size and ε-martensite amount of the steel increase with the tA, which results in the deterioration of its tensile properties.Furthermore, after treated at tA=1200℃, the ε-martensite plate becomes very thin,and the fracture along grain boundary is also observed during tensile test owing to the over-sized austenite grains.