激光直接堆积成形2Cr13不锈钢的组织与力学性能分析

Microstructure and tensile strength property of 2Cr13 stainless steel formed by laser direct metal deposition forming

对2Cr13不锈钢粉末进行激光直接堆积成形,得到一定高度的长方体成形件。使用SEM、XRD检测直接金属堆积(DMD)成形件的显微组织、物相组成,使用显微硬度计测试成形件的硬度,并对成形件进行拉伸性能和抗汽蚀性能测试。结果表明:DMD成形件的显微组织以树枝晶生长方式为主;XRD分析结果显示,DMD成形件组成相为单一的Fe-Cr合金相,堆积层硬度分布在300～350 HV0.2,与调质态相比提高43%;拉伸实验显示,DMD试样平均抗拉强度为932 MPa,比调质态提高了75%,但试样延伸率明显降低。抗汽蚀实验结果表明,DMD成形件的抗汽蚀性能是调质态的1.77倍。因此,可以看出激光DMD成形技术在汽轮机部件的修复上有着良好的应用前景。

Direct forming 2Cr13 stainless steel powder were studies experimentally by laser direct metal deposition（DMD） forming.The microstructure and phase component were studied by using SEM,XRD and the microhardness was measured by microhardness tester.The tensile property and cavitation resistance property were also studied.The test results show that microstructure of the DMD forming sample composed of thin Fe-Cr phase dendritic crystal,the harnesses of the specimens distributed in 300-350 HV0.2 which increased 43% than quenched and tempered 2Cr13.The XRD results show that the DMD component has the single Fe-Cr phase.The tensile strength of the DMD component achieves to 932 MPa,increasing by 75% than substrate.But the extensibility is decreased obviously.And the cavitation resistance of the DMD forming components is increased to 1.77 times of the quenched and tempered steel,which proves that laser direct metal deposition forming has a good potential for repairing the stream turbine components in the future.