高强贝氏体基体钒微合金化TRIP钢的性能

对一种钒微合金化TRIP钢进行冷轧连续退火,研究了钢的组织特征和力学性能。结果表明,贝氏体基TRIP钢的组织由贝氏体/马氏体和少量的残余奥氏体组成。随着贝氏体区等温时间的延长,钢的抗拉强度下降,屈服强度和延伸率提高。残余奥氏体由块状向薄膜状转变,体积分数增加,薄膜状残余奥氏体主要分布在贝氏体板条间,厚度为50-90 nm。在400℃等温180 s连续退火钢板呈现出相对低抗拉强度(960 MPa)、高屈服强度(765 MPa)和高延伸率(22.0%)的特性,而且加工硬化指数(0.20)、各向异性指数(0.94)和强塑积(21120 MPa.%)也较为优良。

Mechanical Properties of High-strength V-microalloyed TRIP-aided Sheet Steel with Bainitic Ferrite Matrix

The microstructural characteristics and mechanical properties of a V-microalloyed TRIP steel after cold rolling and continuous annealing were investigated.The results show that the microstructure of TRIP steel with bainitic ferrite matrix is composed of bainitic/martensite and a small amount of retained austenite.With increasing the bainite holding time,the yield strength and elongation rate of the tested material increase,and the tensile strength decreases.The blocky retained austenites mostly turn into 50-90 nm flims between bainite laths and the volume fraction of retained austenite increases.When holding at 400℃for 180 s,a relatively low tensile strength(960MPa),high yield strength(765MPa) and elongation rate(22.0%) of continuous annealing sheet steel can be obtained,and strain-hardening exponent(0.20), anisotropy exponent(0.94) and tensile strength-plastic performance(21120 MPa.%) are excellent.