A kind of smelting method of titanium micro-alloyed No. 45 steel extra-thick plate

Abstract

The invention discloses a method for smelting titanium microalloyed No. 45 steel extra-thick plate, which is based on the metallurgical process flow of molten iron pre-desulfurization-converter smelting-LF out-of-furnace refining-RH vacuum treatment-thick slab continuous casting. Smelting to produce No. 45 steel extra-thick slab, and then rolling to produce 50-100mm extra-thick plate, the characteristics are: double-slag smelting in the converter smelting process, Ti microalloying during RH vacuum treatment, and continuous casting Reasonable process parameters are adopted in the stage to control the precipitation of TiN, and effectively reduce inclusions and their precipitation size, reduce segregation, reduce the quantity of large-size TiN, and then improve the quality of No. 45 steel; the smelting method of No. 45 steel provided by the present invention. , greatly improve the qualified rate of the surface quality of the 45th steel casting billet, the qualified rate of the first-level flaw detection, improve the degree of central segregation of the steel, reduce the scrap rate of the steel, improve the production efficiency and the finished product rate, and realize the production cost of the steel. reduce.

Description

technical field [0001] The invention relates to the technical field of iron and steel materials, in particular to a method for smelting titanium microalloyed No. 45 steel extra-thick plates. Background technique [0002] No. 45 steel is a high-quality carbon structural steel with medium carbon content, and is one of the most widely used high-quality structural steels. 45 steel has certain toughness and plasticity, high strength, good machinability, and good comprehensive mechanical properties can be obtained by quenching and tempering treatment. Widely used in the manufacture of high-strength moving parts, such as air compressors, pump pistons, steam turbine impellers, etc., heavy and general machinery manufacturing, such as rolling shafts, connecting rods, worms, racks, gears, pins, etc. The No. 45 steel extra-thick plate (50mm ~ 100mm) is mainly used in the mold processing industry and the field of heavy machinery. The pass rate of the internal and external quality of th...

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Problems solved by technology

[0010] The purpose of the present invention is to solve the problem that the conventional smelting method cannot solve the problem of strong crack sensitivity in the continuous casting process of No. 45 steel at present, and cracks at the corners are very easy to occur, and the section of the steel slab is large and the center segregation is serious. , center cracks are prone to occur on the steel plate after rolling, and the yield of steel is low. A method for smelting titanium microalloyed No. 45 steel extra-thick plate is provided.

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