粉末特性对30CrMnSiNi2A钢组织和性能的影响

采用水雾化（water atomization，WA）、气雾化（gas atomization，GA）和等离子旋转电极雾化（plasma rotating electrode process，PREP）方式制备30CrMnSiNi2A钢粉，对比分析了不同雾化粉末的特征及其烧结体的组织与性能。结果表明:不同雾化粉末的形貌、粒度分布、氧含量及流动性等特征均存在一定差异，其中水雾化和气雾化粉末中存在空心粉和卫星粉，等离子旋转电极雾化粉末无内部缺陷，具有优异流动性，且氧含量最低。三种雾化粉末的烧结样品组织均为粒状贝氏体，但呈现出不同的原始颗粒边界形貌，随粉末氧含量的降低，原始颗粒边界处夹杂物尺寸减小，成分由富Al氧化物变为富Al、Si氧化物。相比于水雾化和气雾化粉末，等离子旋转电极雾化粉末的烧结样品拉伸性能最优，其拉伸强度和伸长率分别为1310 MPa和11.5%，这得益于良好的粉末质量和低的氧含量。

Effect of powder characteristics on microstructure and properties of 30CrMnSiNi2A steels

The 30CrMnSiNi2A steel powders were prepared by water atomization (WA), gas atomization (GA), and plasma rotating electrode process (PREP) in this paper. The characteristics of the different atomized powders and the microstructure and properties of the sintered products were compared and analyzed. The results show that, the characteristics of the different atomized powders are different, such as morphology, particle size distribution, oxygen content, and fluidity. The hollow powders and satellite powders exist in the WA and GA powders. The PREP powders have no internal defects, showing the excellent fluidity and the lowest oxygen content. The microstructure of the sintered products using the three atomized powders is granular bainite, but the morphology of the prior particle boundary (PPB) is different. With the decrease of the powder oxygen content, the inclusion size at the PPBs decreases, and the composition changes from Al-rich oxide to Al-Si-rich oxide. Compared with WA and GA powders, the sintered product using PREP powders has the best tensile properties with the tensile strength and elongation of 1310 MPa and 11.5%, respectively, which benefit from the good powder quality and low oxygen content.