Smelting and pouring process of L245 pipeline steel

Abstract

The invention discloses a smelting and pouring process of L245 pipeline steel, and relates to the technical field of metallurgical steelmaking. The production steps of the L245 pipeline steel are strictly controlled, and the process comprises the steps of molten iron component inspection, steel pressing production rhythm control, L245 narrow component control, converter continuous casting, whole-process N content detection, converter smelting process control, optimization of high pulling speed stability of all section blank types of continuous casting, optimization of continuous casting pouring process control and increase of the casting blank corner acid quality detection link. Through acid etching detection of the N content in molten iron and a casting blank in the production process, the N content of a product in the production process is controlled to be 32 ppm on average, the N content of a finished product is controlled to be 48 ppm on average, the N content is reduced by 10-20 ppm compared with the prior art, and the total product inclusion content is reduced by 0.5-1.5 level compared with the prior art; and the edge curling cracks of the pipeline steel are effectively controlled, the casting blank defect offline rate is reduced to 2% or below from 5%, the product qualification rate is increased to 99% or above, a foundation is laid for stabilizing subsequent high-quality variety steel production, and the effect is 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.