Impact and Fatigue Properties of Injection Molded Fe-Ni-C System Low Alloy Steels

摘要

Fe-NiC system low alloy steels have been developed to enhance the mechanical properties of Fe-Ni system which is a popular steel for Metal Injection Molding (MIM) process. Although the assessment of dynamic failure properties such as impact and fatigue strengths are important, there are few reports about the dynamic properties of injection molded Fe-NiC system low alloy steels at the present time.In this study, the behavior of dynamic properties (impact and fatigue strengths) and carbon control by solvent debinding followed by thermal debinding for Fe-2 percent Ni0.7 percent C low alloy steels produced by MIM process was investigated. Retained carbon contents was precisely controlled to 0.7 mass percent by continuous process of thermal debinding and sintering. Dynamic properties of the injection molded steels were superior to those of the conventional PIM steels with the same composition, since the pore structure of the former was finer and more spheroidized as compared to that of the latter.