热处理对SLM 18Ni300马氏体时效钢力学性能的影响

Effect of Heat Treatment on Mechanical Properties of SLM 18Ni300 Maraging Steel

为探究热处理对激光选区熔化(Selective Laser Melting,SLM)成形18Ni300马氏体时效钢力学性能的影响,利用激光选区熔化技术制备18Ni300马氏体时效钢试样,分别对成形试样进行时效处理、固溶处理和固溶+时效处理。通过金相显微镜、扫描电镜、硬度计和拉伸试验机,分别测试分析了不同热处理SLM 18Ni300马氏体时效钢的微观组织、显微硬度和拉伸性能。固溶+时效处理后,SLM 18Ni300马氏体时效钢激光熔池消失;组织为均匀致密的板条马氏体,且均有细小析出物弥散分布于晶界和板条间;抗拉强度和硬度显著提高,但延伸率明显下降。此外,固溶+时效处理后材料的强塑积可以得到改善。

In order to explore the effect of heat treatment on the mechanical properties of 18Ni300 maraging steel formed by selective laser melting(SLM),18Ni300 maraging steel samples were prepared by selective laser melting technology,and the formed samples were respectively treated by aging,solid solution,and solid solution+aging.The microstructure,microhardness,and tensile properties of SLM 18Ni300 martensitic aged steel were tested and analyzed by metallographic microscope,scanning electron microscope,hardness tester,and tensile testing machine.After solid solution+aging treatment,the laser melting pool of SLM 18Ni300 martensitic aging steel disappeared,and the structure was uniform and dense lath martensite,with fine precipitates dispersing in grain boundary and lath;the tensile strength and hardness increased significantly,but the elongation decreased significantly.In addition,the strong plastic deposition of the material can be improved after the solution+aging treatment.