Patent ID: 7906220
Filing Date: 2011-03-15
Classification: B23K,B32B,C22C,C23C,F28F,Y10T

Abstract:
1. A steel/aluminum welded structure comprising: a hot-dip Al-coated steel sheet having a coating layer, consisting of, by mass, 3-12% Si, 0.5-5% Fe and the balance being Al except inevitable impurities, and an Al—Fe—Si ternary alloy layer formed at an interface between a steel substrate and the coating layer; and an aluminum or aluminum alloy sheet spot welded to the Al-coated steel sheet; wherein an area ratio of an Al—Fe binary alloy layer to a whole of an Al/Fe joint boundary is controlled to 90% or less, and an Al—Fe alloy free region exists between the Al—Fe binary alloy layer and the Al—Fe—Si ternary alloy layer, and wherein the coating layer is formed on a steel substrate containing 0.002-0.020% N, and the coating layer is formed on a N-enriched surface of the steel substrate, N concentration of the N-enriched surface being 3.0% or more, by atom.