Smelting and pouring process of l245 pipeline steel

Abstract

The invention discloses a smelting and pouring process for L245 pipeline steel, and relates to the technical field of metallurgy and steelmaking. The invention strictly controls the production steps of L245 pipeline steel, including inspection of molten iron composition, control of pressure steel production rhythm, control of narrow composition of L245, addition of N content detection in the whole process of converter continuous casting, control of converter smelting process, and optimization of the height of each cross-section of continuous casting. The casting speed is stable, the continuous casting pouring process control is optimized, and the acid type quality inspection link at the corner of the slab is added. In the present invention, by detecting the N content in molten steel and the acid corrosion of the slab during the production process, the average N content of the product during the production process is controlled at 32ppm, and the average N content in the finished product is 48ppm, which is 10-20ppm lower than before, and the overall product inclusion The material content is reduced by 0.5 to 1.5 grades compared with the past; and the curling cracks of pipeline steel are effectively controlled, the off-line rate of casting slab defects is reduced from 5% to less than 2%, and the qualified products are increased to more than 99%. The foundation was laid for the production of variety steel, and the effect was remarkable.

Description

technical field [0001] The invention relates to the technical field of metallurgy and steelmaking, in particular to a smelting and casting process for L245 pipeline steel. Background technique [0002] With the development of modern engineering technology, the requirements for the strength, toughness and processing performance of steel are becoming increasingly strict, and the requirements for steel quality are also getting higher and higher. Existing TiO, Al 2 o 3 Inclusion process detection measures are single, TiO, Al 2 o 3 Inclusions exist in the steel as an independent phase, which destroys the basic continuity of the pipeline steel and increases the inhomogeneity of the steel structure. Therefore, the presence of inclusions in steel has a strong impact on the performance of steel. According to the nature, shape, distribution, size and content of inclusions and other factors, the influence on the properties of steel is also different. [0003] TiO, Al 2 o 3 Incl...

AI Technical Summary

Problems solved by technology

[0003] TiO, Al 2 o 3 Inclusions are the key factors affecting the quality and physical properties of L245. Pipeline steel L245 has edge cracks in the coil during rolling, and transverse micro-cracks are prone to appear in the corners of slabs during production. The crack length is about 10mm. , the corner of the slab is cracked at the weak point, and the crack at the corner continues to extend and crack after rolling. The pass rate of the product is only below 80%, and the product inclusions are as high as level 3, and the quality of the final product is unstable.