热处理工艺对新型轻质奥氏体耐磨钢的组织与力学性能的影响

Effect of Heat Treatments on Microstructure and Mechanical Properties of Novel Light-mass Austenitic Wear-resistant Steel

以新型轻质高锰、高铝的奥氏体耐磨钢为研究对象,利用XRD,OM,SEM,EDS观察显微组织和析出物,研究不同的热处理工艺对新型钢种的组织与力学性能影响。结果表明:该新型轻质奥氏体耐磨钢的最佳优化热处理工艺为1050℃保温1h水韧,550℃时效2h,空冷。在最佳热处理工艺条件下奥氏体基体内弥散析出细小的钙钛矿结构(Fe,Mn)3AlC的κ-碳化物颗粒,不仅强化了奥氏体基体,其力学性能也得到明显改善;最优工艺处理后实验钢的硬度、强度、冲击韧度达到了最佳匹配,其抗拉强度为825MPa,屈服强度为574MPa,冲击韧度值为156J/cm2(V型缺口),硬度为271HB;与只进行水韧处理相比实验钢的屈服强度提高40.0%,硬度提高32.2%。

A novel light-mass high Mn-Al austenitic wear-resistant steel was selected as the research object.The microstructure and precipitates were examined by X-ray diffraction（XRD）,optical microscopy（OM）,scanning electron microscopy（SEM）and energy dispersive spectrometer（EDS）.Effect of heat treatments on microstructure and mechanical properties of the novel steel was studied.Results show that the optimum heat treatment is water toughening at 1050℃ for 1hand aging at550℃for 2h,air cooling.Under the condition of the optimum heat treatment,fine（Fe,Mn）3AlC carbides which have a perovskite structure are found to precipitate within the austenite matrix.The fine carbides not only strengthen the austenitic matrix,but its mechanical properties are also improved significantly.The hardness,strength,impact toughness of the experiment steel under the optimal heat treatment reach the best match with a tensile strength of 825 MPa,ayield strength of 574 MPa,a impact toughness values（V-notch）of 156J/cm^2,a surface hardness of 271 HB.Compared with that of the conventional treatment,the yield strength and hardness increase by 40.0% and 32.2%,respectively.