Preparation and printability of 24CrNiMo alloy steel powder for selective laser melting fabricating brake disc

摘要

Spherical 24CrNiMo alloy steel powder used for selective laser melting (SLM) fabricating highspeed train brake disc was prepared by the vacuum induction melting gas atomisation (VIGA) method. Powder morphology, particle size, flowability and microstructure were measured. Part properties fabricated by SLM were investigated via some modern analysis method. The experimental results showed that powder mean particle size D-50 was 75 mu m, flowability was 16.69 s/50 g and apparent density was 4.71 g cm(-3). 24CrNiMo alloy steel specimen microstructures prepared by SLM consisted of proeutectoid ferrite and granular bainite. Average microhardness was 346 HV, tensile strength was 1223 MPa, extensibility was 13.1% and the product of strength and elongation was 16.1 GPa%. 24CrNiMo alloy steel powder prepared by the VIGA method had good laser printability and huge potential application value for SLM-fabricated brake disc.