Patent ID: 6767652
Filing Date: 2004-07-27
Classification: C23C,Y10T

Abstract:
A galvannealed steel sheet superior in workability and comprising a steel sheet plated with an alloy zinc plating, whereinthe steel sheet is characterized by containing silicon in an amount no less than 0.8 mass % and retained austenite in an amount no less than 3% in terms of packing factor; and the alloy zinc plating is characterized by containing Znâ€”Fe alloy crystal grains which exist in its surface layer and have a specific crystal grain size such that the longer side of a crystal grain is no larger than twice the shorter side of the crystal grain and the number of crystal grains with an average particle size no smaller than 4 &mgr;m is no more than 5 per 70Ã—50 &mgr;m.