研究目的
Investigating the effect of laser power on the gradient microstructure and mechanical properties of low-alloy steel samples fabricated by laser melting deposition.
研究成果
(1) The microstructure on cross-section of low-alloy steel samples formed by LMD is gradient. The surface microstructure is a mixture of martensite and lower bainite. The microstructure of the interior is mainly tempered martensite. With the increase of laser power, the size of martensite and lower bainite increases and the tempered martensite gradually coarsened. (2) From surface to interior of the samples built by LMD, the ultimate tensile strength and hardness decreases, the plasticity increases. (3) With the increase of laser power of the samples built by LMD, the ultimate tensile strength of both the surface and interior reduces, and the plasticity of both the surface and interior gradually increases. Hardness of interior of the samples decreases with the increase of laser power. (4) With the increase of laser power from 1500W to 2500W, the percentage of surface thickness to sample thickness increases from 34% to 70%.
研究不足
The study focuses on the effect of laser power on the microstructure and mechanical properties of low-alloy steel samples fabricated by laser melting deposition. The limitations include the range of laser powers tested (1500 W to 2500 W) and the specific chemical composition of the low-alloy steel used.
