Abstract Based on the principle of in-situ precipitation strengthening, TA15 powder (Ti-6.5Al-1Mo-1V-1.5Zr) was used as an additive to improve the mechanical properties of 45CrNiMoY alloy steel by pre-laid laser cladding (PLLC) technology. Effects of the content of TA15 powders (0–1.5 wt%) on the microstructure, precipitation mechanism and mechanical property of PLLC 45CrNiMoY alloy steel samples were investigated. Results indicate that TA15 alloy has a significant effect on the microstructure of 45CrNiMoY alloy steel through metallurgical reaction in the laser molten pool. With the increase of TA15 powder content, the granular bainite (GB) microstructure were remarkably refined, the mount of the acicular ferrite (AF) was increased, and in-situ precipitates such as Ti-Y2O3-Zr (TYZ) composite oxide, TiC and ZrC carbide were produced. The 45CrNiMoY alloy steel sample with 1.0 wt% TA15 alloy addition has the best combination of tensile strength (1158 ± 9.7 MPa) and elongation (9.8 ± 0.4%), its microhardness was improved by 25.6% compared with the sample without TA15 powder. The TYZ composite oxides did not only serve as the AF nucleation sites but also spheroidize the detrimental manganese sulfide phase leading to a good elongation of the 45CrNiMoY alloy steel, the TiC and ZrC carbides played a key role in the improvement of the microhardness and tensile strength. The proper addition of TA15 powder can effectively improve the microstructure and mechanical properties of the PLLC 45CrNiMoY alloy steel.

中文翻译：

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激光预熔覆技术制备高力学性能TA15粉末增强45CrNiMoY合金钢

摘要 基于原位析出强化原理，以TA15粉末（Ti-6.5Al-1Mo-1V-1.5Zr）为添加剂，通过预制激光熔覆（PLLC）提高45CrNiMoY合金钢的力学性能技术。研究了 TA15 粉末的含量（0-1.5 wt%）对 PLLC 45CrNiMoY 合金钢样品的显微组织、析出机制和力学性能的影响。结果表明，TA15合金通过激光熔池中的冶金反应对45CrNiMoY合金钢的显微组织产生显着影响。随着TA15粉体含量的增加，粒状贝氏体（GB）显微组织显着细化，针状铁素体（AF）含量增加，Ti-Y2O3-Zr（TYZ）复合氧化物、TiC等原位析出物和 ZrC 碳化物。添加1.0 wt% TA15合金的45CrNiMoY合金钢试样具有最佳的抗拉强度（1158±9.7 MPa）和延伸率（9.8±0.4%）组合，与未添加TA15粉末的试样相比，显微硬度提高了25.6%。TYZ 复合氧化物不仅作为 AF 成核位点，而且使有害的硫化锰相球化，导致 45CrNiMoY 合金钢的良好延伸率，TiC 和 ZrC 碳化物在显微硬度和抗拉强度的提高中起关键作用. TA15粉末的适当添加可以有效改善PLLC 45CrNiMoY合金钢的组织和力学性能。6% 与不含 TA15 粉末的样品相比。TYZ 复合氧化物不仅作为 AF 成核位点，而且使有害的硫化锰相球化，导致 45CrNiMoY 合金钢的良好延伸率，TiC 和 ZrC 碳化物在显微硬度和抗拉强度的提高中起关键作用. TA15粉末的适当添加可以有效改善PLLC 45CrNiMoY合金钢的组织和力学性能。6% 与不含 TA15 粉末的样品相比。TYZ 复合氧化物不仅作为 AF 成核位点，而且使有害的硫化锰相球化，导致 45CrNiMoY 合金钢的良好延伸率，TiC 和 ZrC 碳化物在显微硬度和抗拉强度的提高中起关键作用. TA15粉末的适当添加可以有效改善PLLC 45CrNiMoY合金钢的组织和力学性能。