抄録
High speed steel and low alloy steel were bonded by powder sintering processes in order to investigate the effects of carbon content of high speed steel and sintering temperature on the bonding behavior. Two type bonding methods were studied, i.e. the process A in which high speed steel and low alloy steel green compacts were bonded by sintering without a bonding pressure, and the process B in which two-layer powders of the steels compacted and then sintered. The density, microstructure and four-point bending strength of the bonded specimens were examined. It was found in the process A that the two steels were not bonded at lower sintering temperature than the temperature (Ts) at which the relative density of sintered high speed steel reached 98%, and that bonded specimens showed the highest bending strength at higher sintering temperature than the Ts by 20K. In the process B, there was no significant influence of carbon content and sintering temperature on the bending strength, and the maximum bending strength was lower than that of the bonded specimens by the process A. This was considered to be due to both the micro-pores produced at the interface and the residual tensile stress of the bonded specimens.
