采用激光选区熔化技术成形S-04钢试样,研究了热处理前后成形试样的显微组织及力学性能。结果表明,成形试样的致密度最高可达99.791%,热处理前后试样均由α′马氏体和少量γ残余奥氏体构成;热处理前试样具有激光选区熔化技术特有的多层堆积特征,热处理后该特征消失且试样物相主要为束状马氏体;热处理后试样的室温力学性能优于热处理前试样。 S-04 steel samples were formed by laser selective melting and the microstructure and mechanical properties of the formed samples before and after heat treatment were studied. The results show that the compactness of the as-formed sample is up to 99.791%. The samples before and after heat treatment consist of α ’martensite and a small amount of γ-retained austenite. The samples before heat treatment have multi-layer stacking characteristics After heat treatment, the feature disappears and the sample phase is mainly martensite. The room temperature mechanical properties of the sample after heat treatment are better than those before heat treatment.