Deformation of material in punching of slanted fine hole in SUS304 sheets with fine-grained microstructure

It is necessary to understand behaviors of the material in worked sheet to reduce troubles of punch fracturing in the punching of slanted fine holes in austenitic stainless-steel SUS304 sheets. The behavior of the material is estimated as the follows by the map of Vickers hardness in the cross-section of worked sheet. The material flow changes the complexity of what as a result of the influence of work hardening or transformation to strain-induced martensite. Then, the direction and magnitude of the pressure applied to the punch also change such inn a complex manner. However, the worked material almost flows into the die hole. Then, the punch is carried into the hole by this material flow.