Effect of Cr, Mo, and V Elements on the Microstructure and Thermal Fatigue Properties of the Chromium Hot-Work Steels Processed by Selective Laser Melting

Metals

Yan Wu¹  Bo Liang²  Mei Wang²  Xianhui Gao³  Wei Li³  Qingsong Wei³  Bo You⁴ 

[1] Institute of Advanced Integration Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China;Rongcheng College, Harbin University of Science and Technology, Rongcheng 264300, China;School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China;School of Mechanical and Power Engineering, Harbin University of Science and Technology, Harbin 150080, China;

关键词: selective laser melting (SLM);    chromium hot-work steels;    alloying elements;    high-temperature properties;    thermal fatigue;   

DOI  :  10.3390/met12050735

来源: DOAJ

【 摘 要 】

Thermal fatigue is the main failure mode for chromium hot-work steels. In this study, pre-alloyed chromium hot-work steel powders with three different Cr, Mo, and V addition levels (low content (LH), medium content (MH), and high content (HH)) were used for selective laser melting (SLM). The microstructure and thermal fatigue properties of these SLM-processed materials were investigated. After thermal fatigue tests, LH possessed the lowest hardness (approximately 573 HV₅) and longest crack length, MH possessed the highest hardness (approximately 688 HV₅) and HH (with the hardness of approximately 675 HV₅) possessed the shortest crack length. It can be concluded that the increase of V content in MH is the main reason for the refined grains which result in an enhanced hardness and thermal fatigue resistance compared to LH. The further increase of the Cr and Mo content in HH leads to the grain coarsening and hardness decreasing, which is supposed to degrade the thermal fatigue resistant properties according to the conventional theory. However, HH exhibited an enhanced thermal fatigue resistance compared to MH. That is because the higher stored energy in MH deteriorated its thermal fatigue resistance compared to HH.

【 授权许可】

Unknown