Hot rolling container steel without punctiform surface defect and manufacturing method thereof

Abstract

The invention discloses hot rolling container steel without a punctiform surface defect, which is characterized in that the hot rolling container steel is manufactured from the following elements in percentage by weight: 0.05-0.20 of C, 0.05-1.00 of Si, 0.2-2.0 of Mn, 0.05-0.20 of P, 0.05-0.60 of Cu, 0.20-0.80 of Cr, 0-0.60 of Ni, no more than 0.010 of S, 0.015-0.060 of Als, no more than 0.020 percent of Sn, no more than 0.020 percent of As, and the remaining is iron and non-avoidable residue. The manufacturing method of the hot rolling container steel is as following: firstly, the raw material steel plate base of the hot rolling container steel is obtained by desulfurization, converting and blowing, and continuous casting of molten iron, and then heating, rough rolling after scaling, primary rolling, refine rolling, laminar flow cooling and coil treating are carried out on the raw material steel plate base. The problems that container steel generates punctiform and salix-leaf-shaped defects on the surface after being heated in a heating furnace for 180 minutes or after being heated in a normal heating condition for 60-180 minutes are solved by the manufacturing method disclosed by the invention.

Description

technical field [0001] The invention relates to the technical field of steel smelting and rolling, in particular to a hot-rolled container steel without point surface defects and a manufacturing method thereof. Background technique [0002] With the development of steel products for containers, the mechanical properties of the products are gradually improving. Since the steel for containers contains more alloying elements such as Ni, Cu, and Cr, surface quality problems are prone to occur in production, and it is these surface quality These problems restrict the improvement of the overall quality of container steel. Among these surface quality problems, the thin strips and point-like oxide scale defects appearing on the surface have become the main defects of container steel. The emergence of defects caused the downgrade and change of judgment of the product, which caused great economic losses to the steel company. [0003] In order to eliminate the surface crack defects c...

AI Technical Summary

Problems solved by technology

However, in actual production, it is found that the steel billet in the heating furnace often waits for a long time (≥180min) in the furnace due to the problem of the equipment in the subsequent process. In this case, the surface of the container steel will produce serious damage. Defects such as surface dots and willow leaves

In addition, when the heating time is short and the rough rolling adopts multi-pass descaling, the container steel containing Cu and Ni will still produce point-shaped and willow-shaped surface defects, especially the residual low-level defects such as Sn and As in the steel. When melting point elements, the problem of point-like and willow-like surface defects is more serious

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