Process optimization and microstructure of C250 maraging steel prepared by SLM process

doi:10.13251/j.issn.0254-6051.2023.03.025

Abstract

Abstract: C250 maraging steel was prepared by SLM process. Effect of SLM process parameters on relative density and microstructure of the C250 maraging steel by means of metallographic microscopes (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), electron backscattered diffraction (EBSD), transmission electron microscopy (TEM) and density measurement devices. Morphology and microstructure of the C250 maraging steel prepared by optimizing SLM process were analyzed. The results show that when the energy density is 85-120 J/mm³, relative density is higher than 99.5%, and the microstructure is dense without obvious defects. When the laser power is 270 W, the scanning rate is 700 mm/s, the scanning spacing is 0.11 mm, and the powder layer thickness is 0.03 mm, the density of the C250 maraging steel reaches 100%. Under the optimal SLM process, main phase composition of the C250 steel is martensite, which reaches 97.13%, and its internal grains are extremely fine, about 2.7 μm. In the martensite matrix there are also strengthening phases and dislocations to strengthen the C250 steel.

Key words: maraging steel, selective laser melting, relative density, solidification of metal

CLC Number:

TG142.7

Liu Zaixi, Lu Dehong, Wang Changjun, Liu Yu. Process optimization and microstructure of C250 maraging steel prepared by SLM process[J]. Heat Treatment of Metals, 2023, 48(3): 143-150.

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