Laser & Optoelectronics Progress, Volume. 58, Issue 19, 1914006(2021)
Microstructure and Comprehensive Properties of Laser-Melted Stainless Steel
To explore the influence of the laser melting process on the comprehensive properties of stainless steel (SS) surface, we selected the LDF 4000-40 laser to treat the 0Cr17Ni12Mo2 SS surface and then used the optical and electron microscopes, an energy spectrum scanner, the microhardness and electrochemical analysis testers, and an abrasion testing machine to characterize the microstructure and performance. The results show that owing to the differences in heat transfer and cooling conditions in different regions, the macroscopic morphology of laser-melted SS is wavy at the interface with the matrix, the strengthened zone's surface layer comprises equiaxed crystals, the middle zone comprises equiaxed and columnar crystals, and the edge areas comprise flat crystals. Carbon, iron, and chromium elements are diffused in the strengthened zone. Because laser melting refines the microstructure, the highest microhardness of the strengthened layer is about 1.5 times higher than the highest hardness of the substrate. The strengthened layer has a stronger corrosion resistance than the substrate. However, once the strengthened layer is corroded, its corrosion rate is higher than that of the matrix. Owing to grain refinement and increased microhardness, the friction coefficient of the strengthened layer (0.29) is lower than that of the matrix (0.35), and the wear mechanism of the strengthened layer is abrasive wear.
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Zixuan Wang, Yanjiao Hu, Ming Pang. Microstructure and Comprehensive Properties of Laser-Melted Stainless Steel[J]. Laser & Optoelectronics Progress, 2021, 58(19): 1914006
Category: Lasers and Laser Optics
Received: Nov. 2, 2020
Accepted: Feb. 17, 2021
Published Online: Oct. 14, 2021
The Author Email: Hu Yanjiao (yjhu@cauc.edu.cn)