A Heating Process for Avoiding Surface Defects of Steel Plate

Abstract

The invention relates to a heating process for avoiding surface defects of steel plates. The specific process flow is as follows: continuous casting machine produces slabs, slabs are cut and sprayed, slabs are heated in a heating furnace, slabs are initially rolled, slabs are finished rolled, coiled Take the package and cut the finished product; before the slab is heated in the heating furnace, the temperature of the slab is controlled. The specific reaction conditions are as follows: control the surface temperature of the slab to be higher than the Ar3 temperature or control the surface temperature of the slab to be lower than the Ar1 The temperature is higher than 200°C. The invention discloses a heating process for avoiding surface defects of the steel plate. The invention not only realizes the hot delivery and hot charging of the slab without increasing any equipment and production costs, but also makes full use of continuous casting Billet waste heat, to achieve a good energy-saving effect. It also makes it easier to remove the oxide scale on the surface of the steel plate, fully dissolves the carbonitrides during the heating process, improves the high-temperature plasticity of the steel, and avoids surface defects such as slag inclusions and cracks on the steel plate after rolling.

Description

technical field [0001] The invention relates to a heating process for avoiding surface defects of steel plates, belonging to the technical field of metallurgical continuous casting. Background technique [0002] The technological process of continuous casting slab rolling into steel plate is: slab production by continuous casting machine → slab cutting and spraying → slab temperature control → slab entering into heating furnace for heating → slab preliminary rolling → slab finishing rolling → coiling Bale → finished product slitting (steel plate). [0003] Among them, the hot delivery and hot charging technology of slab into the heating furnace is a major breakthrough in continuous casting technology. It can not only save energy and reduce consumption, but also has far-reaching significance for the reform of traditional industrial structure. The economic benefits are greatly improved. However, it is very difficult to realize the technology of slab hot delivery and hot char...

AI Technical Summary

Problems solved by technology

However, it is very difficult to realize the technology of slab hot delivery and hot charging at present, because many steel types are relatively sensitive to the furnace temperature, and the temperature of the furnace is too high or too low to easily form the surface defects of the rolled material, so that It is difficult to control the surface quality and internal quality of hot coil

[0004] In addition, the heating process of the slab in the heating furnace has a profound impact on the uniformity of the hot coil product quality and mechanical properties. The slab heating process directly affects the microstructure and grain size of the final product. Improper heating and uniformity The heating temperature and the long heating and soaking time are the root causes of the large fluctuations in the performance of the final product

[0005] At present, most of the research on the control of steel plate surface crack defects is focused on smelting, ladle refining, hot rolling process, recrystallization, thermomechanical rolling, deformation compression optimization, cold rolling process, etc., but the surface temperature before loading the slab into the heating furnace Insufficient understanding and attention to control and control of heating furnace slab heating process

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