粉末冶金马氏体-奥氏体复合钢的组织与性能研究

Microstructure and properties of powder metallurgy martensitic-austenitic composite steel

近年来,汽车、建筑等领域对高强度-高塑性金属材料的需求日益增长,为了获得高强度-高塑性的金属材料,粉末冶金技术发挥着越来越重要的作用。通过放电等离子烧结技术(SPS)烧结质量比为2:1的马氏体钢和奥氏体钢混合金属粉末,复合钢的奥氏体相均匀分布于马氏体相当中,试样致密度高达95.5%,并通过后续的热轧处理,提高复合钢的烧结质量,致密度提高至98.9%。热轧后复合钢的屈服强度、抗拉强度、均匀伸长率和总伸长率分别为960 MPa、1529 MPa、6.7%和6.7%。在热轧的基础上引入冷轧+短时间高温回火处理,粉末冶金复合钢性能进一步提高。其中冷轧30%/500℃回火5 min的复合钢,屈服强度、抗拉强度、均匀伸长率和总伸长率分别为1899 MPa、1964 MPa、9.2%和10.0%。

In recent years,the demand for high-strength-high-plasticity metal materials in the fields of automobiles and ships has been increasing.In order to obtain high-strength-high-plasticity metal materials,powder metallurgy technology plays an increasingly important role.In this study,the mixed metal powders of martensitic steel and austenitic steel with a mass ratio of 2:1 were sintered by spark plasma sintering(SPS),and the austenite phase was uniformly distributed in the martensite phase.The density of the sample is as high as 95.5%,and through the subsequent hot rolling treatment,the sintering quality of the composite steel is improved,and the density is increased to98.9%.The yield strength,tensile strength,uniform elongation and total elongation of the clad steel after hot rolling are 960 MPa,1529 MPa,6.7%and 6.7%,respectively.On the basis of hot rolling,cold rolling+short-time high temperature tempering treatment is introduced,and the performance of powder metallurgy composite steel is further improved.Among them,the clad steel cold-rolled at 30%-500℃and tempered for 5 min has yield strength,tensile strength,uniform elongation and total elongation of 1899 MPa,1964 MPa,9.2%and 10.0%,respectively.