Laser additive manufacturing of M2 high-speed steel

Abstract

M2 high-speed steel samples were fabricated by laser additive manufacturing and tempered at different times at a temperature of 560°C. The microstructures of deposited samples were characterised by fine equiaxial grains, dendrites and inter-dendritic network-shape eutectic carbides and were composed of supersaturated martensite, retained austenite and M2C-type carbides. The content of retained austenite gradually decreased with increasing tempering times. Meanwhile, the micro-hardness of deposited samples was 688 ± 10 HV, while the first, second and third tempering times were 833 ± 13 Hv, 710 ± 6 Hv and 740 ± 7 Hv, respectively (standard deviations).Wear resistances of all samples showed an adhesive wear mechanism, and M2 HSS without tempering had a lower friction coefficient with an average of 0.52. M2 HSS after tempering twice at 560°C/2 h had a larger wear volume loss than others.

Rapid Solidification Microstructure and Carbide Precipitation Behavior in Electron Beam Melted High-Speed Steel

“…Up until now, there have been few publications on high-speed steels fabricated by SLM [13][14][15][16][17] and blown powder AM. [18] The carbon content in those steels (including M2, [13,14,18] M50 [16] and a high-strength Fe85Cr4Mo8V2C1 [15] ) were all below 1.0 wt pct, except for a very recent work on an SLM M3:2 steel. [17] With the increasing carbon content, higher hardness and wear resistance can be achieved, but this poses challenges for processing due to material susceptibility to cracking.…”

Additive Manufacturing of a Cold‐Work Tool Steel using Electron Beam Melting

“…Another positive side effect is the possibility of reducing post‐processing costs and lead‐time in the fabrication of the tools. Reports from both SLM and EBM‐processed maraging and tool steels can be found in the literature . Mainly hot‐work tool steels have been attempted by EBM .…”

Fabrication of Ultrafine Grained High Speed Steel with Satisfactory Carbide Dissolution by Electropulsing Treatment

“…5,24,25) While the grain size of laser additive manufactured or laser treated HSSs ranges from 2-15 μm. 26,27) However, formation of network eutectic carbides and coarse dendrites is inevitable during the solidification of laser melted zone, probably deteriorating the toughness and ductility of HSSs. Thus, EPT is a promising way to ultra-refine the grain size of HSSs unaffected by reticulated eutectic carbides.…”