Author(s)

Suiyuan Chen, Ruixue Wang, Jing Ma, Jing Liang, Tong Cui, Changsheng Liu

Corresponding Author

Suiyuan Chen

Abstract

12CrNi2Re alloy steel powder was used as raw material, 12CrNi2Re alloy steel with rectangular(10mm thick) was prepared by laser additive manufacturing. Effect of scanning speed on microstructure and properties of 12CrNi2Re alloy steel were studied by OM, SEM, XRD, micro hardness tester and tensile test.The results show that the phases composition of 12CrNi2Re alloy steel are bainite and carbide (Cr,Fe)7C3. Thermal accumulation was led due to thermal cycling during the preparation of samples by laser additive manufacturing, the heat loss was much lower than the laser input energy, the cooling rate was slow and bainite transformation happened during the preparation of 12CrNi2Re samples. The scanning speeds increased from 3mm/s to 7mm/s, the laser energy input decreased accordingly, the thermal accumulation temperature decreased when 12CrNi2Re alloy steel samples prepared by laser additive manufacturing, the isothermal transformation time of granular bainite was shorter, the size of the granular bainite became smaller as the scanning speed increased. When the scanning speed was 5mm/s, the hardness, tensile strength, yield strength, elongation and contraction rate of sample are favorable, and it has good application value.

Keywords

laser additivemanufacturing technology, Bainite transformation, 12CrNi2Re alloy steel, nuclear power emergency diesel generator crankshaft.