ABSTRACT In order to improve the manufacturing efficiency, the high power SLM technology was used to fabricate the 24CrNiMoY alloy steel. Effects of laser energy volume density (EVD) and tempering temperature on the microstructure and properties of HP-SLM 24CrNiMo steel were studied. Results show that as the EVD increases, the grows direction of lath martensite microstructure changes to disordered. When EVD is 120 J mm−3, the UTS of HP-SLM 24CrNiMoY steel reaches 1125 ± 15 MPa. High UTS is benefit from the fine martensite lath and high density of dislocations. Additionally, tempering treatment can reduce the dislocation density in martensite and promote the precipitation of ϵ carbides. After tempering at 500°C, the EL of HP-SLM 24CrNiMoY steel increased to 7.5% and the product of strength and plasticity increased by 37.8%. This study provides a technical reference for HP-SLM technology to prepare the high-performance 24CrNiMoY alloy steel.

中文翻译：

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不同激光能量密度和回火温度下高功率SLM 24CrNiMoY合金钢的组织与性能

摘要 为了提高制造效率，采用大功率SLM技术制造了24CrNiMoY合金钢。研究了激光能量体积密度(EVD)和回火温度对HP-SLM 24CrNiMo钢组织和性能的影响。结果表明，随着EVD的增加，板条马氏体组织的生长方向变为无序。当EVD为120 J mm−3时，HP-SLM 24CrNiMoY钢的UTS达到1125±15 MPa。高 UTS 受益于精细的马氏体板条和高密度的位错。此外，回火处理可以降低马氏体中的位错密度，促进ϵ碳化物的析出。500℃回火后，HP-SLM 24CrNiMoY钢的EL增加到7.5%，强度和塑性乘积增加了37.8%。