HEAT RESISTANCE COATED ZINC-55% ALUMINUM ALLOY PLATED STEEL SHEET EXCELLENT IN PRESS WORKABILITY

• Main Authors: NAKAMURA TAKAFUMI, SUGAWARA HIROSHI, ISHIKAWA HANJI, OZAWA HIRONORI
• Format: Patent
• Language: English
• Published: 26.05.1998
• Edition: 6
• Subjects: 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; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

PROBLEM TO BE SOLVED: To produce a heat resistance coated Zn-55% Al alloy plated steel sheet in which flaws hardly occur on a plating layer even if volatile press oil having low viscosity is used at the time of press forming. SOLUTION: This heat resistance coated Zn-55% Al based alloy plated steel sheet is formed of a Zn-Al based hot dip plating layer in which grain size is regulated to <=1mm, surface roughness Ra is regulated to 0.1 to 1μm, and hardness HV is regulated to >=100, and the surface of this plating layer is applied with heat resistant film of fluorine base or the like. In the spangles, i.e., crystal grains of the plating layer, the grain size is regulated to <=1mm by rapid cooling treatment immediately after the plating. As for the rapid cooling, an atomizing method of water, a water-air mixture, an aq. soln. of chloride or the like, or a cold air spraying method can be adopted.