基于激光直接沉积技术的增减材复合制造核用304L不锈钢接头性能研究

Research on joint performance of 304L stainless steel for unclear via an additive and reductive hybrid manufacturing based on laser direct deposition technology

针对3D打印技术设计自由、几何柔度高和成形复杂结构的技术优势,结合传统制造加工成本低、效率高的工艺特点,以核用304L奥氏体不锈钢为研究对象,基于激光直接沉积(DLD)技术开展了传统轧制与选区激光熔化(SLM)3D打印成形304L零部件增减材复合制造工艺研究,对304L核用不锈钢进行了DLD工艺参数验证,包括显微组织、拉伸和冲击力学性能、以及晶间腐蚀性能测试。研究发现,DLD成形的核用304L不锈钢具有高的性能稳定性,平行样品之间离散小,材料拉伸强度、塑性延伸率、冲击韧性及晶间腐蚀性能均满足材料验收性能要求。采用验证后的DLD工艺对SLM材料和传统轧板进行连接,连接部位熔合良好,无影响接头性能的显微裂纹及沉淀物析出,材料表面无损检测满足验收要求。基于DLD技术的传统工艺与SLM增减材复合制造工艺,综合了传统工艺与3D打印的工艺技术优势,性能满足验收要求。

In this study,taking advantages of free design,high geometric flexibility and forming complex structure combining of the 3D printing technology,combining with the traditional manufacturing process features of low cost and high efficiency,and using 304L austenitic stainless steel for nuclear as the object of study,an additive and reductive hybrid manufacturing procedure combining with traditional rolling and selective laser melting(SLM) is used for 3D printing forming of 304 L stainless steel parts based on direct laser deposition(DLD) technology. The DLD technological parameters of 304 L stainless steel for unclear are verified,including microstructure,mechanical properties and inter-granular corrosion resistance tests. The result shows that 304 L stainless steel processed by DLD technology has high performance stability,small dispersion between parallel samples,and good tensile strength,high impact property and excellent corrosion intergranular corrosion resistance property, which all meet the acceptance requirements. The verified DLD proce-dure is used to join the SLM material and the traditional rolling plate,the joint part is well fused with no micro-cracks and precipitation affecting the joint performance and the nondestructive testing on the sample surface also meets the acceptance requirements. Based on DLD technology,the additive and reductive hybrid manufacturing procedure combining with traditional manufacturing and SLM process has the technical advantages of traditional procedure and 3D printing,and the material performance meets the acceptance requirements.