Prevention of oxidation in hot stamping of quenchable steel sheet by oxidation preventive oil

Oxidation in hot stamping of quenchable steel sheets heated in an electrical furnace was prevented by coating the sheets with oxidation preventive oil. A solid film is generated on the surface of the sheet by drying the coated sheet, and the film changes into a liquefied film having an oxidation barrier at elevated temperatures. Hot hat-shaped bending of the coated sheet was performed to examine the properties of the products. For the bent products, the oxidation preventive oil was effective, the shape accuracy was very high and the hardness increased to a level of 1.5 GPa in tensile strength.