RUST PREVENTIVE STEEL SHEET FOR AUTOMOBILE FUEL TANK EXCELLENT IN WELDABILITY AND CORROSION RESISTANCE

• Main Authors: FUDA MASAHIRO, MAKI JUN, OKADA NOBUYOSHI, ISAKI TERUAKI
• Format: Patent
• Language: English
• Published: 17.02.1998
• Edition: 6
• Subjects: APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; METALLURGY; PERFORMING OPERATIONS; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; SPRAYING OR ATOMISING IN GENERAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING

PROBLEM TO BE SOLVED: To obtain a rust preventive steel sheet for a fuel tank having press workability and corrosion resistance in the environment of organic matter without using Pb by applying resin chromate coating film having specified thickness to the surface of an aluminum-plated steel sheet and remarkably improving its weldability. SOLUTION: This steel sheet is the one in which one side or both sides of a hot dip aluminum-plated steel sheet contg., by weight, 2 to 13% Si and in which the coating weight is regulated to <=50g/m per side are applied with resin chromate coating having 0.1 to 2μcoating thickness. As for Si, in the case it is not >=2%, the effect of reducing the alloy layer is thin, and in the case it is >13%, the effect saturates, and Si is electrochemically easy to form into a cathode to deteriorate the corrosion resistance of the plating layer. As for the coating weight of the plating, the upper limit is set for securing its weldability. As for the coating thickness of the resin chromate coating, in the case of <=0.1μ, the coating sound as resin can not be formed, and on the other hand, in the case of >2μ, its resistance value is made too high, the conduction between the electrode and the steel sheet or between the steel sheets is disturbed, and welding can not be executed.