Patent ID: 9551057
Date: 2017-01-24
CPC Classifications: B32B,C21D,C22C,C23C,Y10T

Claim:
1. A galvannealed layer formed directly on a surface of a base steel sheet, wherein the average amount of Fe in the galvannealed layer is in a range of 8.0 to 12.0%; and wherein the absolute value of a difference (ΔFe) between the amount of Fe at a position of 1/8 of the thickness of the galvannealed layer and the amount of Fe at a position of 7/8 of the thickness of the galvannealed layer in the galvannealed layer, the thickness being from an interface between the galvannealed layer and the base steel sheet to the external surface of the galvannealed layer, is in a range of 0.3 to 3.0%, wherein the base steel sheet comprises a volume fraction of 10-50% bainitic ferrite and/or bainite.