Formation of an Aluminide Coating on Hot Stamped Steel

Abstract

The degradation of type 1 aluminized coating during hot stamping leads to the coating cracking due to the formation of a brittle Fe AI, intermetallic phase. The formation of an aluminide coating prior to hot stamping was investigated as a method to simultaneously improve the coating ductility and achieve a good hot corrosion resistance of the hot stamped parts. A formable aluminide coating was obtained when the coating alloying was achieved during the pre-heating of the steel and an Fe content higher than 70 atc/o (83 wt%) was reached. The coating was identified as Fe(3)Al phase at room temperature. The formation of this aluminide coating on 22MnB5 hot stamping steel was investigated in detail. The effect of this alternative hot stamping thermal cycle on the room temperature mechanical properties of the steel was also investigated.