A wide variety of mechanical properies is possible in the metal injection molding (MIM) process. However, there still remains the issue of controlling the carbon content and structure in the final product by the difference of powder type. In this paper, MIM process for the 4600 steels has been studied by using prealloyed fine powder (average particle size: 12μm) contained 0.71wt.% carbon.
For the debinding approach, solvent debinding followed by final thermal debinding consisted of heating at 0.066K/s to 1173K produced the homogeneous structure and stiff compact enough for handling. The residual carbon content was mainly controlled by changing the fraction of H₂in gas mixture of H₂ and N₂ during the final thermal debinding. Mechanical properties of the sintered and the heat treated MIM compacts with prealloyed fine powders were inferior to those of the same treated MIM compacts with elemental mixed powders, especially in the ductility. This is due to the insufficient desification of prealloyed fine powder (relative sintered density : 93-94%) and the difference of microstructures.