METHOD OF PRODUCING AN ALUMINUM-ZINC ALLOY COATED FERROUS PRODUCT TO IMPROVE CORROSION RESISTANCE

摘要

METHOD OF PRODUCING AN ALUMINUM-ZINC ALLOYCOATED FERROUS PRODUCT TO IMPROVE CORROSION RESISTANCEAbstract of the DisclosureThis invention relates to an aluminum-zinc alloycoated ferrous base product which exhibits improved atmos-pheric corrosion resistance, and to the process whereby suchimproved corrosion resistance may be realized. The processis characterized by the steps of heating such coated productto a temperature within the single phase region for thecomposition corresponding to the aluminum and zinc of saidcoating, defined as a in the FIGURE in the accompanyingdrawing, preferably at a temperature between about 650°F(343°C) to 750°F (399°C), for a period of time to solutiontreat the aluminum-zinc alloy coating overlay, and coolingslowly to at least 350°F (177°C). The resulting product ischaracterized by improved atmospheric corrosion resistanceas a result of the combination of an aluminum-zinc alloycoating overlay having a structure comprised of a finedispersion of beta-zinc within a matrix of alpha-aluminum,and a thin intermetallic layer interposed between saidoverlay and said ferrous base.-1-