Method for manufacturing ring-type pull top and use of steel plate provided with protective layer for ring-type pull top

摘要

The present invention relates to the use of a steel plate provided with a protective layer for producing a ring-type pull top or a can equipped with a ring-type pull top. Steel sheets are produced by non-alloy or low alloy steel materials with a carbon content of less than 0.1% by weight and related processes. The problem of using a conventional steel sheet with a protective layer, that is, the problem of providing a steel sheet for producing a ring-type pull top having a weak peeling force due to a constant residual wall thickness of a notch line is 75 K / s or more. It is achieved by a steel sheet that has been recrystallized and annealed at a heating rate, cooled at a cooling rate of at least 100 K / s after the recrystallization heat treatment, and subsequently coated with a protective layer. [Selection] Figure 1