Effect of heat treatment on microstructure and mechanical properties of SLM 316L stainless steel spiral microwire

doi:10.13251/j.issn.0254-6051.2021.07.020

Abstract

Abstract: Effects of different heat treatment parameters on the structure and mechanical properties of the spiral micro-diameter wire (SS316L-HMDW) made by laser melting (SLM) were analyzed through microscope observation, tensile test and microhardness test. The results show that after heat treatment, microstructure of the SS316L-HMDW specimen changes significantly, and the laser melt pool disappears, which reduces the anisotropy and contributes to the improvement of mechanical properties. Under different holding time, the grain size of the SS316L-HMDW specimen increases in different degrees with the holding time; with the increase of heat treatment holding time, the yield limit and tensile strength of the SS316L-HMDW specimen decreases, the elongation increases, and all of the fracture surfaces of tensile test specimens are ductile fracture, and the dimples become larger. After heat treatment at 1200 ℃ for 2 h, the microstructure and mechanical properties of the SS316L-HMDW specimen change significantly. The tensile strength decreases from 585 MPa to 398 MPa, the yield strength decreases from 40 MPa to 25 MPa, and the elongation significantly increases to 268%. The plasticity and toughness of the specimens are enhanced.

Key words: selective laser melting, helical micro-diameter wire, heat treatment, microstructure, mechanical properties

CLC Number:

TG166

Li Bin, Dong Xiuping, Huang Mingji. Effect of heat treatment on microstructure and mechanical properties of SLM 316L stainless steel spiral microwire[J]. Heat Treatment of Metals, 2021, 46(7): 103-107.

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