Steel for hard tinplate bottle caps and production method thereof

Abstract

The invention relates to steel for bottle caps and a preparation method thereof, especially to steel for hard tinplate bottle caps and a production method thereof. The invention mainly solves the technical problems of unstable rolling, high hole ratio for pickling-rolling and poor surface quality of each process during pickling-rolling production of present steel for bottle caps. The technical scheme provided by the invention is as follows: the steel for hard tinplate bottle caps comprises the following chemical components of: by weight, 0.045-0.088% of C, Si being less than or equal to 0.1%, 0.30-0.50% of Mn, P being less than or equal to 0.020%, S being less than or equal to 0.020%, 0.010-0.060% of Alt, N being less than or equal to 0.0060%, and the balance Fe and some unavoidable impurity elements. The production method comprises four steps of steeling-making, hot rolling, pickling-rolling and continuous annealing, and is characterized in that hot rolling is controlled in the way: tapping temperature is 1200+/-30 DEG C, finishing temperature is 880+/-30 DEG C and coiling temperature is 580+/-30 DEG C; cooling mode is forepart cooling; pickling-rolling and continuous annealing are controlled in the way: RTF section temperature is 610+/-15 DEG C and SF section temperature is 610+/-15 DEG C. Hardness of the obtained tinplate finished product is HR30T63+/-3. The production method provided by the invention is mainly used for production of steel for bottle caps.

Description

technical field [0001] The invention relates to a steel for bottle caps and a preparation method thereof, in particular to a steel for bottle caps with a hard tin-plated substrate and a production method thereof. Background technique [0002] Tinplate is a cold-rolled low-carbon thin steel plate or steel strip coated with pure tin on both sides. It is an important raw material for making various packaging containers such as food cans and beverage cans. [0003] Theoretical research shows that: during the equilibrium solidification process of Fe-C alloy, the steel that undergoes peritectic reaction is called peritectic steel, that is, steel with a mass fraction of carbon between 0.09 and 0.53, peritectic steel, especially sub-peritectic steel. High sensitivity to surface cracks. At present, most bottle cap steels are made of T5 material. Since the C content of this type of hard tinplate is in the sub-peritectic region, the surface quality of the slab is poor. Different from...

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Problems solved by technology

[0004] The purpose of the present invention is to produce a steel for hard tin-plated substrates for bottle caps and its production method, which mainly solves the problems of unstable rolling, high porosity in acid rolling and various problems encountered in the acid rolling production of bottle cap steel. Technical problems with poor process surface quality

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