m32高速钢粉末包套热挤压工艺及组织性能分析.docx

Abstract
High speed steel is widely used in cutting tool, cold and hot work mould, other high wear-resisting, high temperature resistant cutting materials and structure parts field, which has high hardness, wear resistance, toughness and high cutting toughness. High speed steel can be manufactured according to the melting method, but the materials contain carbide segregations and the defect of abnormal grain growth. Compare to this traditional method of manufacturing, powder metallurgy high speed steel can eliminate or decrease these defects and bination property of materials. In order to solve the defects of powder metallurgy high speed steel manufacture such plex process, difficult plastic process, thick carbides and inferior performances, this article manufactured bars for M32 powder metallurgy high speed steel by employing the numerical simulation, powders canned hot-extrusion and follow-up heat treatment technology routes.
Water-atomized M32 steel powder, sample of extrusion and different treatment process were systematically characterized by the X-ray diffraction (XRD), scanning electron microscope (SEM), and particle-size analyze (PAS), optical metallographic microscope (OM), analytical balance (AB) and universal electronic test machine (UTM).
First, M32 HSS powder canned hot extrusion was analyzed by using the DEFORM-2D finite element numerical simulation technology. This two dimensional finite element analysis can not only qualitative analyze HSS powder flow law and the distribution of the field of hot extrusion process, the covering powder hot extrusion forming law was revealed, but simulate the effects of different sheath size on extrusion effect. The simulation results show that powders canned hot-extrusion effect is in the most ideal condition when sheath bottom and wall thickness are 5mm.
Water-atomized M32 high speed steel powder used in this study was irregular in shape. The average particle size of the powder is 98μm. The irregular powder partic