Acid-washing hot-rolled low-carbon steel without line defects on surface and production method thereof

Abstract

The invention discloses an acid-washing hot-rolled low-carbon steel without line defects on the surface and a production method thereof. The hot-rolled low-carbon steel consists of the following components in percentage by weight: 0.02 to 0.12 percent of C, 0.05 percent or less of Si, 0.10 to 0.60 percent of Mn, 0.015 percent or less of P, 0.010 percent or less of S, 0.10 percent or less of Cu, 0.10 percent or less of Ni, 0.05 percent or less of Cr, 0.010 to 0.070 percent of Als, 0.010 percent or less of Sn, 0.010 percent or less of As, 0.010 percent or less of Sb and the balance of iron; moreover, As plus Sn plus Sb are less than or equal to 0.015 percent, and the ratio of Ni to Cu is greater than or equal to 0.5. The production method of the hot-rolled low-carbon steel includes the following steps: after molten iron desulfurization and converter blowing, a raw sheet billet of the hot-rolled low-carbon steel is obtained, and the raw sheet billet of the hot-rolled low-carbon steel sequentially is subjected to continuous casting, heating, scale removal before rough rolling, rough rolling, finish rolling, laminar flow cooling, rolling, fan cooling and acid-washing. While the mechanical property of the steel is guaranteed by the components of the raw steel, the surface defects of the acid-washinghot-rolled low-carbon steel are reduced, consequently, the surface quality of the steel is greatly increased, and economic loss is reduced.

Description

technical field [0001] The invention relates to the technical field of steel smelting and rolling, in particular to a hot-rolled low-carbon steel with no surface defects after pickling and a manufacturing method thereof. Background technique [0002] With the improvement of users' requirements for steel quality, the requirements for steel surface quality are also getting higher and higher. On the other hand, in order to promote the recycling of steel and reduce the resource consumption of the whole society, steel production enterprises usually add a certain amount of scrap steel when making steel. Since the scrap steel contains a certain amount of residual elements, if the production process is not properly controlled, Will inevitably bring surface quality problems. Especially for low-carbon steel, surface defects like peaks, black lines or dots are more likely to appear on the surface after pickling, which seriously affects the surface quality of the product. economic los...

AI Technical Summary

Problems solved by technology

2) Try to control the time of the slab in the furnace as much as possible. The time of the cold slab in the furnace is controlled at 160-180 minutes.

However, in actual production, it is found that when Cu, Sn, and As are less than 0.02%, hot-rolled low-carbon steel will still produce peak-shaped surface defects after pickling

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