Steel plate for bottle cap, manufacturing method thereof, and bottle cap

Abstract

An object of the present invention is to provide a steel plate for bottle caps having excellent workability and a method for producing the same, and a bottle cap formed by molding a steel plate for bottle caps, which eliminates the problems of poor shape and insufficient compressive strength of the bottle caps. Steel sheets for bottle caps contain: C: 0.0005-0.0050%, Si: 0.020% or less, Mn: 0.10-0.60%, P: 0.020% or less, S: 0.020% or less, Al: 0.01-0.10%, N: 0.0050% or less , Nb: 0.010-0.050%, and the remainder is composed of Fe and unavoidable impurities, the average r value is 1.30 or more, and YP is 450MPa-650MPa. The steel billet is subjected to hot rolling with a billet reheating temperature of 1150°C or higher and a finishing temperature of 870°C or higher, then coiled at a coiling temperature of 600°C or higher, and after pickling, cold-rolled once to recrystallize at a temperature above and Annealing is performed at an annealing temperature of 790° C. or lower, and then secondary cold rolling is performed at a rolling reduction of 10% to 50%, thereby obtaining a steel plate for bottle caps.

Description

Technical field [0001] The present invention relates to a steel plate for bottle caps, which is excellent in shape uniformity during forming of bottle caps used in beer bottles and the like, and a manufacturing method thereof, and a bottle cap. Background technique [0002] In recent years, from the viewpoint of reducing environmental load and cost, the steel plate for bottle caps used in beer bottle caps and the like has been promoted to be thinner. Generally speaking, there are the following two types of thinner steel plates. That is, they are SR (Single Reduce) materials that are subjected to temper rolling followed by hot rolling, cold rolling, and annealing, and DR (Double Reduce) materials that are subjected to secondary cold rolling. In the case of steel plates for bottle caps, the demand for steel plates with a thickness of 0.20 mm or less is increasing, and it is expected that a DR that implements secondary cold rolling that can compensate for the reduction in compressi...

AI Technical Summary

Problems solved by technology

In the case of a steel sheet with low workability, there may be a shape defect in which the wrinkle shape becomes uneven

Bottle caps with uneven wrinkle shape have the following problems: even if they are capped on the bottle, the compressive strength cannot be obtained, and the content will leak, and the function as a bottle cap cannot be performed.

In addition, even if the wrinkle shape is uniform, if the strength of the steel plate is low, there is a risk that the cap will fall off due to insufficient compressive strength.