MIM 42CrMo4 is a versatile low alloy steel and commonly used in the forging industry. Its properties can be varied with a tailored hardening and tempering treatment over a wide range of strength|ductility combinations. Its high ductility is beneficial for gears, connecting rods, crankshafts, pistons and other automotive and machinery components. This makes that steel grade also attractive for the Metal Injection Molding and Additive Manufacturing industry. Therefore, MIM 42CrMo4 hardened was chosen as third material – after MIM 8620 case-hardened and MIM 100Cr6 hardened – for the internal high cycle fatigue and notch sensitivity study. As presented in the years before, two different injection molding methods and resulting weld line positions were compared. Moreover, the mean stress sensitivity, notch sensitivity, scatter and further s-N line parameters were discussed and compared with the previously characterized MIM steel grades. Its response on a variety of tempering regimes was investigated too.
