Method for improving low-carbon aluminum killed steel blank hot cracks by adopting low-voltage pulse current

Abstract

The invention discloses a method for improving low-carbon aluminum killed steel blank hot cracks by adopting low-voltage pulse current, belonging to the technical field of improving the steel blank hot cracks. According to the method disclosed by the invention, when a low-carbon aluminum killed steel blank is cut by a continuous casting machine, pulse current is applied to the low-carbon-aluminumkilled steel blank; the pulse current parameters are as follows: the pulse voltage is 21-35 V, the pulse current is 35-100 A and the pulse frequency is 20-50 Hz; and low-carbon aluminum killed steel is the aluminum killed steel with omega[C] which is less than 0.25%, wherein omega[Al] is more than or equal to 0.01% and less than or equal to 0.40%. According to the method disclosed by the invention, the low-voltage pulse current is adopted, microcosmic tissues of the low-carbon aluminum killed steel blank are changed, and the high-temperature mechanical property of a casting blank is improved,so that the hot cracks of the casting blank are effectively reduced; and the normal production is not influenced by the method, the existing production process does not need to be changed, alloy elements do not need to be added, temperature-reduction treatment does not need to be carried out on the casting blank, no pollution to the casting blank and equipment is generated, and no harms on workers are formed, so that the method is an environment-friendly, safe and new technology for reducing defects of the casting blank.

Description

Technical field [0001] The present invention is a technical field that improves the cracks of casting blank heat. More specifically, it involves a method that uses low -voltage pulse current to improve low -carbon aluminum sedation steel casting blanks.The steel casting blank micro -organization and high temperature mechanical performance, the present invention is particularly suitable for the steel species that are prone to the cracks of casting blanks (red -send) cracks. Background technique [0002] The twenty -century oil crisis has a huge impact on the world's large energy consumption. In order to save energy, metals and funds, developed countries have successively developed various energy -saving technologies, bringing a lot of changes in production processes.Among them, the heat -delivery process of the Lianhuang blank can not only greatly reduce energy consumption, shorten the product production cycle, but also reduce the area of the factory building. This technology has ...

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Problems solved by technology

However, these methods also have certain limitations: ① adding alloy method, this method will increase the production cost, if the steel type has strict requirements on the composition, it cannot be used; ② molten steel composition control method, this method is difficult to control in actual production, If the steel type has strict requirements on the composition, it cannot be used; ③ high-temperature billet hot charging method, which is currently difficult to realize in actual production; ④ cast billet cold charging method, which is easy to operate and is currently the most commonly used method, but reduces production efficiency. And after the slab is cooled, the temperature will be raised again, the heat will be lost in vain, and the production cost will be relatively high; It is quite difficult, and currently only a few steel plants in foreign countries are using it, and because the surface of the slab needs to be cooled, there is still a certain loss of slab heat

In addition, the problem of hot delivery cracks in low-carbon aluminum-killed steel slabs in the prior art needs to be solved urgently to improve the quality of slabs

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