Patent ID: 8440323

Claim:
A coated steel stamped product, comprising: a strip of base steel having a first side and a second side; and a coating on at least one of said first side of said strip of base steel and said second side of said strip of base steel, wherein said coating results from the interdiffusion between said base steel, and aluminum or aluminum alloy pre-coating, and wherein said coating comprises, proceeding from the base steel outwards, an Interdiffusion layer having a hardness HV50 g between 290 and 410 (HV50 g designating the hardness measured under a load of 50 grams), an Intermediate layer having a hardness HV50 g between 810 and 1100, an Intermetallic layer having a hardness HV50 g between 522 and 715, and a Superficial layer having a hardness HV50 g between 810 and 1100, and said entire coating comprises, in surfacic fraction, less than 10% of porosities.