Study On M32PM HSS Rotary Swaging Forging And Heat Treatment

Powder metallurgy high speed steel with high hardness, high wear resistance, red hardness and other excellent properties, is widely used in cutting tool industry. Especially in recent years due to the difficult cutting material (such as high temperature alloy, titanium alloy, high strength steel) application expands unceasingly, makes the demand for high performance of high speed steel is more and more big. Compared with the traditional casting-forging high speed steel, powder metallurgy method to eliminate the defect of carbide segregation, can be prepared in high speed steel material with excellent comprehensive properties. The preparation of PM high speed steel most mature, most widely used industrial method is hot isostatic pressing (HIP), the utility model has the advantages of stable and excellent performance, shortcoming is complex process, high cost, high power consumption and the blockade of foreign technology. This paper hopes to use water atomized M32high-speed steel powder with relatively cheap price by extrusion and hot rotary forging, last modified make excellent PM high speed steel by heat treatment. Study on rotary forging and heat treatment process of M32PM high speed steel, for the future of rotary forging process and heat treatment process of high speed steel to provide reference.Scanning electron microscope, X-ray diffraction, particle size analyzer, metallographic microscope, analytical balance, universal testing machine, Rockwell hardness tester and other equipment for the test and analysis system of the sample of M32high speed steel powder, high speed steel of rotary forging and different heat treatment process. This study uses water atomized M32high speed steel powder prices relatively cheap, powder morphology was irregular shape, its average particle size of powder is120μm.After rotary forging, the M32PM high speed steel pore and carbide have uniform distribution, the main organization for the body-centered is cubic lattice martensite, in addition a small amount of residual face-centered cubic austenite and carbide. The hardness, flexural strength, density ratio of high speed steel by rotary forging is better than extrusion without the rotary forging process. With the increase of rotary forging deformation, mechanical properties of high speed steel gradually improve.Through the study of heat treatment find that:when rotary forging temperature is1100℃, the quenching temperature is1190℃, the carbide of M32PM high-speed steel is granular, small and dispersed in the matrix of tempered martensite, pores were round or oval, the size of most pores is less than2μm. M32PM high speed steel mechanical properties under this condition make excellent performance. Hardness of 66.4HRC, red hardness up to63.4HRC, bending strength was4906.14MPa, flexural strength reached the level of ultra high strength steel. The study also find that macroscopic mechanical properties of M32PM high speed steel has a close relationship with microstructure structure, pore size and shape, carbide shape and size.