Abstract
Although remarkable progress has been made in the techniques of metal injection molding (MIM) process, application of MIM process to wide variety of alloy steel powders is necessary to fully extend this novel mass production technique. In this paper, MIM process for the Cr-Mo steels has been investigated by using prealloyed fine powder (average particle size : 12μm) contained 0.17wt% carbon. The results were summarized as follows:
1) By using continuous process which went on through the thermal debinding and the sintering, the compacts were considerably densified to a relative density of about 95%.
2) In the case of using the hydrogen and nitrogen gas mixture as the final thermal debinding atmosphere, residual carbon content was little in the sintered compacts. However, the residual carbon content was widely controlled by adjusting the carbon monoxide gas content during the thermal debinding.
3) Heat treated SCM415 MIM steels showed a tensile strength of 1200 MPa, which is equivalent to those of the powder forged steels.
