Abstract
The effects of carbon (C) addition and debinding temperature on sintering behavior of Cr-Mo steel compacts shaped by metal injection molding were invetigated to carry out the control of C content of the sintered compacts. The specimens were made of SCM415 steel powder and additional C powder with polyamide binder. The amount of C addition was varied from Og to 0.6g per 100g of metal powder. The specimens were debound in air at temperatures ranging from 553K to 603K for 7.2ks, and were sintered in argon gas at 1623K for 7.2ks. The relationship between carbon (C) and oxygen (O) contents of debound compacts versus those of sintered compacts was analyzed by introducing a parameter, ΔCd=Cd-aOd (a=C/O atomic weight ratio) which represents the stoichometric ratio of C and O contents of debound compacts (Cd and Od, respectively). The obtained results showed that the reaction MxO+C→xM+CO (M=Metal element) is dominant for reducing oxides during sintering process and the excess or shortage of C reducing oxides in compact can be estimated successfully by ΔCd introduced in this study.
