Study on Microstructure and Properties of 18Ni300 Steel Fabricated by Selective Laser Melting
Author of the article:CHEN Shuai;TAO Fenghe;JIA Changzhi
Author's Workplace：Shijiazhuang Branch, Army Engineering University, Shijiazhuang 050003, China
Key Words：selective laser melting 18Ni300 steel microstructure property
Abstract：
The 18 Ni300 steel samples were fabricated by selective laser melting(SLM) technique. The influence of laser energy density on relative density and microhardness was analyzed, and the internal relationship between microstructure and properties was investigated. The results show that the central area of molten pool is a uniform cell structure, the transition zone is a small cell structure, and the heat affected zone is a coarse cell structure or a flat structure. The microhardness of the transition zone is higher than that of the central zone under the same laser energy density. With the decrease of the laser line energy density, the pore defects of the sample increase and the microstructure is not uniform,resulting in the decrease of its relative density and microhardness. When the laser line energy density is too large, the microstructure is too coarse, and the relative density and microhardness will decrease. When the laser line energy density η is 543 J·m^-1, the microstructure is uniform and the relative density is the highest, reaching 99.76%, and the microhardness is the highest. The central area and transition area of the molten pool are 351 HV and 355 HV, respectively.
