Microstructure evolution and mechanical properties of a hot-rolled directly quenched and partitioned steel containing proeutectoid ferrite-猫眼课题宝

含先共析铁素体热轧直接淬火配分钢的组织演变及力学性能

DOI：

10.1016/j.msea.2014.04.030

发表时间：

2014-06

期刊：

Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing

影响因子：

6.4

通讯作者：

中科院分区：

材料科学1区

文献类型：

作者：

Zhiping Hu;Fei Peng;Di Wu;Guodong Wang

采用热轧直接淬火配分（HDQ&P）工艺对一种低碳钒微合金化钢进行了热处理。显微组织为多边形先共析铁素体和板条马氏体，并伴有块状和薄膜状残余奥氏体。与现有的不含铁素体的HDQ & P钢相比，这种HDQ & P钢具有较低的屈强比和相似的抗拉强度和延伸率。设计了不同时间的分配工艺，以优化残余奥氏体的特性并控制其稳定性。通过对比HDQ&P板和TRIP板的显微组织和力学性能，研究了HDQ&P板的组织-性能关系、残余奥氏体的稳定性和相变诱发塑性（TRIP）行为。结果表明，先共析铁素体的引入在保证材料较低屈服强度的同时，加剧了未转变奥氏体中碳、硅分布的不均匀性。特殊的元素分布导致大量的块状残留奥氏体位于铁素体/马氏体边界或铁素体包围的某些区域。HDQ&P钢的高抗拉强度是由于其主要的马氏体组织、铁素体中的含V析出相和残余奥氏体的TRIP效应。HDQ&P钢综合了双相钢、TRIP钢和Q&P钢的优点，具有良好的强度、屈强比和塑性的综合性能，具有很大的应用潜力。

A low carbon V microalloyed steel was treated by hot-rolling direct quenching and partitioning (HDQ&P) processes. The microstructures were characterized by polygonal proeutectoid ferrite and lath martensite accompanying with both blocky and film-like retained austenite. This kind of HDQ&P steel possesses a lower yield ratio and similar tensile strength and elongation when compared with the existing HDQ&P steel without ferrite. Partitioning processes with different time were designed to optimize the characteristics of the retained austenite and to control its stability. The microstructure–properties relationship, the stability of the retained austenite, and the transformation-induced plasticity (TRIP) behavior were investigated by comparing the microstructures and mechanical properties of the HDQ&P sheets with those of the TRIP sheets. The results show that the introduction of proeutectoid ferrite can ensure the low yield strengths of the materials and simultaneously intensify the inhomogeneous distributions of carbon and silicon in the untransformed austenite. The particular element distributions result in a considerable amount of large blocky retained austenite locating on the ferrite/martensite boundaries or in some regions surrounded by ferrite. The high tensile strength of the HDQ&P steel can be attributed to the major martensitic structure, the V-bearing precipitates in ferrite and the TRIP effect of the retained austenite. The outstanding combination of strength, yield ratio and ductility, which synthesizes the advantages of dual-phase (DP) steel, TRIP steel and Q&P steel, indicates that the HDQ&P steel has a great potential for practical application.