3D打印18Ni300模具钢的显微组织及力学性能

Microstructure and Mechanical Properties of 3D Printing 18Ni300 Die Steel

通过选区激光熔化(SLM)技术3D打印制备了18Ni300模具钢棒状试样,并对其进行了840℃固溶+490℃×6h时效热处理,分别对热处理前后试样的显微组织及力学性能进行了研究。结果表明:3D打印18Ni300模具钢的致密度高,相对密度接近100%;未经过热处理的3D打印试样显微组织由细小的板状马氏体和残余奥氏体组成,抗拉强度和屈服强度较低;经热处理后试样的显微组织形貌呈均匀分布的长条状,抗拉强度、屈服强度和硬度明显升高,塑性降低。

18Ni300die steel rod samples were prepared by selective laser melting（SLM）3D printing technology,and then the prepared samples were heat treated by process of 840 ℃solid solution and 490 ℃ ×6h aging.The microstructure and mechanical properties of the 3D printing samples before and after heat treatment were studied.The results show that the 3D printing 18Ni300 die steel had high density and the relative density was close to 100%.The microstructure of 3D printing sample without heat treatment composed of martensite and retained austenite,and the tensile strength and yield strength were relative low.The microstructure of 3D printing sample after heat treatment showed uniform trip morphology,and the tensile strength,yield strength and hardness increased obviously and the plasticity decreased.