Abstract
The effects of sintering temperature on the mechanical properties of high speed steels were investigated. The test specimens were formed by injection molding techniques using SKII51 water atomized powders mixed with organic binder. After thermal debinding under vacuum condition, the specimens were sintered at the temperatures between 1518K and 1538K for 3.6ks under the reduced pressrure at 400 Pa of nitrogen gas, then quenched and double tempered at 833K for 5.4ks. The following results are obtained :
1) The density of sintered specimen is increased with the sintering temperature. The density is also saturated at 1528K.
2) Vickers hardness and transverse rupture strength are increased with the sintrering temperature, and the specimen sintered at 1528K showed the hardness of 820Hv and the strength of 3630MPa. The strength is decreased above the sintering temperature of 1533K because of the precipitation of coarse carbides at the grain boundaries.
