Patent ID: 6159622
Filing Date: 2000-12-12
Classification: C23C,Y10S,Y10T

Abstract:
A galvannealed steel sheet, comprising a base metal and a galvannealed coating, which is formed on the surface of the base metal, wherein the base metal has the following chemical composition on the basis of percent by weight and the average grain size on the surface of the base metal is 7 .mu.m or less:C: up to 0.01%; Si: 0.03 to 0.3%;Mn: 0.05 to 2%; P: 0.017 to 0.15%;Al: 0.005 to 0.1%; Ti: 0.005 to 0.1%;Nb: up to 0.1%; B: up to 0.005%;balance: Fe and incidental impurities;wherein the average grain size on the surface of the base metal is finer than the grain size below the surface of the base metal.