Partial resistance tempering of hot-stamped components made of 22MnB5 for subsequent bending

Abstract The manganese-boron alloy 22MnB5 is particularly used for structural and safety-relevant parts in the automotive industry. Parts made from this are usually produced using hot forming process. Here, sheet heated to over 950 °C an industrial roller hearth furnace. then simultaneously formed quenched a cooled tool with temperature gradient of more than 27 K/s. This leads formation martensitic microstructure hardness value 450 HV10 elongation at break less 6%. small strain potential such components makes them difficult form after hot-stamping. Due high gradients resistance heating, can be heat-treated locally without large transition zone. soften already hot-stamped subsequent operations as bending. Within scope paper, heating 22MnB5+AlSi stripe 3 mm width. could consequently bent angle 90° cracking substrate.