22MnB5 Performance as Surface Protection Mask Under Harsh Forging Conditions and its Wear Insight

Herein, the applicability and performance of 22MnB5 steel sheets as protective masks over hot forging dies has been analyzed. Two masks were obtained following two different approaches; by heat treatment of flat sheets in cooling conditions similar to the process of hot stamping and hot stamping on the axial geometry of a cylindrical part. In both processes the sheets were austenitized at 1100° C for 7 min and to obtain bainite microstructure, they were maintained at temperatures higher than 700°C. The flat and axial masks have been subjected to 100 forging cycles for each geometry and positioned on the lower surface of hot forging dies. Surface integrity has been analyzed from microhardness profiles, roughness tests, thickness measurements, optical and electron microscopy. Wear mechanisms have been observed in both masks which was more expressive in the axial mask. Abrasive wear and plastic deformation have been actively observed in both masks; however, they have shown firmness for application as masks.

Keywords:
Protective mask; Tool live; 22MnB5; hot stamping