时效处理对Fe-12Mn-8Al-1C-3Cu轻质钢的组织演变和力学性能的影响  

Effect of Aging Treatment on Microstructure Evolution and Mechanical Properties of Fe-12Mn-8Al-1C-3Cu Lightweight Steel

作　　者：刘加晓 胡晓 丁桦 LIU Jiaxiao;HU Xiao;DING Hua(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;Key Laboratory of Lightweight Structural Materials,Liaoning Province,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学材料科学与工程学院,沈阳110819 [2]东北大学辽宁省轻量化用关键金属结构材料重点实验室,沈阳110819

出　　处：《材料研究学报》2024年第5期356-364,共9页Chinese Journal of Materials Research

基　　金：国家自然科学基金(U1760205)。

摘　　要：对中锰轻质钢进行不同时间的时效处理,研究了时效时间对其微观组织演变和力学性能的影响。结果表明,时效处理时间对析出物有显著的影响。时效时间短于30 min时,在奥氏体基体内析出大量调幅分解生成的弥散分布的晶内κ’碳化物。随着时效时间的延长,除了在晶内析出κ’碳化物,在晶间也发生共析反应在晶界处形成κ-碳化物,构成(α-铁素体+晶间κ-碳化物)片层组织。晶内κ’碳化物的生成使钢的强度提高,但是晶间κ-碳化物的析出使其塑性显著降低。与长时时效相比,短时时效使钢的强度显著提高,还使其保持较高的伸长率,使其具有更优异的综合力学性能。时效30 min的钢,其抗拉强度为1031 MPa,屈服强度为784 MPa,伸长率为41.08%,强塑积为42.35 GPa·%。By aging treatment of a medium manganese lightweight steel at 550oC,the evolution of its microstructure and mechanical properties was analyzed.The results indicate that aging treatment has a significant impact on precipitates.When the aging time is less than 30 minutes,a large number of intra-granularκ'-carbides formed by spinodal decomposition,which distributed dispersedly in the austenite ma-trix.As the aging time increases,besides the intragranularκ'-carbides,intergranularκ-carbides are also formed at grain boundaries through eutectoid reactions as a layered structure ofαferrite andκ-carbide.Intragranularκ'-carbides greatly increase the strength,but intergranularκ-carbides significantly reduce the ductility of the steel.Compared with long-time aging,the strength of the steel can be significantly increased by short-time aging,while the steel still maintains a high elongation with better overall mechani-cal properties.Among them,the good performance is achieved for the steel after aging for 30 minutes,namely a tensile strength of 1031 MPa,yield strength of 784 MPa,an elongation of 41.08%,and a prod-uct of strength and elongation of 42.35 GPa·%.

关 键 词：金属材料 轻质钢 时效处理 组织演变 应变硬化 位错滑移 

分 类 号：TG142.1[一般工业技术—材料科学与工程]