15MnB钢强韧化新工艺及其机理研究

本文研究了15MnB 钢强韧性随淬火温度的变化规律;并通过一系列微观分析,探讨了强韧化机理.研究表明:15MnB 钢冷拔后直接进行临界点及其附近双相区淬火,强韧性优于常规淬火,在低温回火后尤为显著;低温淬火马氏体组织具有较高的强韧性主要归因于晶粒细化作用;铁素体对复相组织性能的影响取决于两相间变形的协调性,它受控于铁素体的形态与体积分数、两相强度、加载方式等多种因素.

STRENGTHENING-TOUGHENING PROCESS OF 15MnB STEEL AND ITS MECHANISM

An investigation is made on the variation of mechanical properties with quenching temperatures in 15MnB steel.Microstructure analysis is conducted systematically to eluci-date the mechanism of strengthening-toughening. The results show that strength and toughness obtained by critical or sub-critical point hardening are superior to those obtained by conventional heat treatment.High strength and toughness resulting from low temperature quenching are mainly attributed to the fine grains.The influence of ferrite on mechanical properties depends on deformation accom-modation of ferrite and martensite,which is controlled by many factors,such as volume fraction and morphology of ferrite,tempering temperature,loading state,etc.