STEEL SHEET WITH COAT AND METHOD OF MANUFACTURE OF SUCH SHEETS Russian patent published in 2003 - IPC

FIELD: manufacture of stainless steel sheets; metallurgy. SUBSTANCE: proposed steel sheet has protective coat applied to at least one surface which is stable to delamination at temperature of about 540 C. Protective coat includes internal inorganic part and external organic part. Inorganic part of coat has density no less than 50 mg/sq m and is made in form of chromium-based converted coat no more than 0.02 mm thick. Converted coat includes solid particles of silicon oxide at mass ratio of chromium to silicon oxide of 1: 1 to 1:2. External organic part of coat includes silicon paint coat containing 40-60 mass-% of silicon resin. Silicon paint coat is dried at temperature of not below 300 C during one minute, after which thermoplastic acryl copolymer and lubricating agent or polyolefin is applied. Mass of acryl copolymer includes 5-70 mass-% of lubricating agent at content of polyolefin in lubricant of 90%. Steel sheet with lubricating coat is dried at temperature of 25-120 C for at least one minute for forming film, 0.0005 to 0.020 mm thick at friction coefficient about 0.05 and density of coat of 10 to 5000 mg/sq m. Dried silicon paint coat with lubricating coat which is not adhesive possesses moisture-, oil- and mud-repellent properties. Steel sheet with silicon coat may be easily molded at minimum delamination of dried silicon paint coat with no additional outside lubricant. EFFECT: enhanced heat and corrosion resistance at good adhesion. 12 cl