[T6] AM Beam Based Technologies

[15B-T6-11] The Microstructure and Tensile Properties of Selective Laser Melted Dievar Hot Work Tool Steel

*M.-W. Wu¹, Z.-S. Shih¹, M.-H. Ku¹, S.-H. Chang¹, Y.-L. Tsai¹, C.-L. Li² (1.National Taipei University of Technology, Taiwan, 2.Voestalpine Technology Institute (Asia) Co., Ltd., Taiwan)

Keywords:selective laser melting, hot work tool steel, microstructure, mechanical property

Selective laser melting (SLM) is the dominant additive manufacturing (AM) process of metallic materials to date. The objective of this study was to investigate the effects of heat treatment on the microstructure and tensile properties of SLM Dievar chromium-molybdenum-vanadium alloyed hot work tool steel. The hardening treatment followed by two tempering processes was applied for the steel. The microstructure was analyzed by scanning electron microscope, energy dispersive spectrometry, X-ray diffractometer, and electron backscatter diffraction. The results show that the yield strength (YS), ultimate tensile strength (UTS), and tensile elongation of as-built steel were 1142 MPa, 1799 MPa, and 10.4 %, respectively. The YS, UTS, and tensile elongation of heat-treated steel were respectively 1472 MPa, 1622 MPa, and 10.4 %. The heat treatment obviously increased the YS, but decreased the UTS. The correlations between the heat treatment, microstructure, tensile properties, and fracture are discussed in this study.