激光选区熔化成形2 GPa级超高强钢及其热处理  

Preparation of 2 GPa ultra-high strength steel by selective laser melting and its post-heat treatment

作　　者：杨天宝 沈鹏 陈雯[1,2] 任英志 黄涛 唐倩[1,2,4] 李坤 YANG Tian-bao;SHEN Peng;CHEN Wen;REN Ying-zhi;HUANG Tao;TANG Qian;LI Kun(College of Mechanical and Vehicle Engineering,Chongqing University,Chongqing 400044,China;Chongqing Key Laboratory of Metal Additive Manufacturing(3D Printing),Chongqing 400044,China;School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China;State Key Laboratory of Mechanical Transmission,Chongqing 400044,China)

机构地区：[1]重庆大学机械与运载工程学院,重庆400044 [2]金属增材制造(3D打印)重庆市重点实验室,重庆400044 [3]郑州大学机械与动力工程学院,河南郑州450001 [4]机械传动国家重点实验室,重庆400044

出　　处：《材料热处理学报》2022年第6期86-93,共8页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金面上项目(51975073);中央高校基本科研业务费(2021CDJQY-024)。

摘　　要：采用激光选区熔化(SLM)技术制备了均匀致密的MS1超高强马氏体模具钢,并对其进行了850℃固溶1 h+550℃时效4 h的热处理,采用扫描电镜、显微硬度仪和万能试验机等研究了打印态和热处理态试样的微观组织和力学性能。结果表明:MS1超高强马氏体模具钢SLM打印态的组织主要由板条状马氏体和奥氏体组成,组织均匀细小,但存在少量微小气孔;热处理后,MS1超高强马氏体模具钢的组织为细小的全马氏体板条,微小气孔缺陷消失;与打印态试样相比,热处理态试样的强度显著增加,塑性有所降低,屈服强度提升超过1倍,抗拉强度超过2 GPa,提升70%以上,硬度提升82%以上,伸长率由10.7%降至5.6%。The uniform and dense MS1 ultra-high strength martensitic die steel was prepared by laser selective melting(SLM) technology, and then it was subjected to solution treatment at 850 ℃ for 1 h and aging at 550 ℃ for 4 h. Microstructure and mechanical properties of the as prepared and heat treated samples were studied by means of scanning electron microscopy, microhardness tester and universal testing machine. The results show that the microstructure of the as prepared MS1 ultra-high strength martensitic die steel is mainly composed of lath martensite and austenite, with uniform and fine grains, but there are a small number of micro pores. After heat treatment, the microstructure of the MS1 ultra-high strength martensitic die steel is fine full martensitic lath, and the micro pore defect disappears. Compared with the as prepared sample, the strength of the heat-treated sample increases significantly, the plasticity decreases, the yield strength increases by more than one time, the tensile strength exceeds 2 GPa, with an increase by more than 70%, the hardness increases by more than 82%, and the elongation decreases from 10.7% to 5.6%.

关 键 词：激光选区熔化 MS1超高强马氏体模具钢 热处理 微观组织 力学性能 

分 类 号：TG142.3[一般工业技术—材料科学与工程]