Method and apparatus for heating steel sheet

Abstract

The invention proposes a method for heating a steel sheet wherein the generation of buckling can be prevented regardless of presence or absence of rolls restraining the steel sheet by antecedently heating the widthwise central portion of the steel sheet with a solenoid type induction heating coil having a convex form projected onto the surface of the steel sheet toward an upstream side in rapidly heating the continuously traveling steel sheet, whereby an isotherm of the steel sheet in the heating is a convex form toward the upstream side, so that a large wrinkle is generated on the steel sheet, and also proposes a heating apparatus used in this method.

Dependencies are inferred from the claim text.