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-aluminum killed 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 invention belongs to the technical field of improving cracks in casting slabs during hot delivery, and more specifically relates to a method for improving cracks in hot delivery of low-carbon aluminum-killed steel slabs by applying a low-voltage pulse current. Steel billet microstructure and high-temperature mechanical properties, the invention is especially suitable for steel types that are prone to cracks in hot casting (red feeding). Background technique [0002] The two oil crises in the 20th century had a huge impact on the world's steel, which is a major energy consumer. In order to save energy, metals and funds, industrially developed countries have successively developed various energy-saving technologies and brought about many changes in production processes. Among them, the continuous casting slab hot delivery and hot charging process can not only greatly reduce energy consumption, shorten the product production cycle, but also reduce the...

AI Technical Summary

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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