A low-carbon structural steel smelting method to prevent pinhole defects in steel ingots

Abstract

The invention provides a low-carbon structural steel smelting method for preventing pinhole defects in steel ingots, comprising the following steps: EAF eccentric bottom tapping electric arc furnace smelting → LF refining outside the furnace → VD furnace vacuum degassing treatment → mold casting pouring → preliminary rolling Billet opening → rod rolling → flaw detection, after the vacuum degassing treatment in the VD furnace, the temperature drop of the molten steel for mold casting is 0.8-1.3°C / min; the pouring temperature in the mold casting is 1575-1585°C; A steel ingot mold ingot tray is used in the casting pouring, and the casting pouring rate is 30-65 kg / s for the ingot body of the steel ingot mold, and 5-15 kg / s for the cap mouth of the steel ingot mold. The method makes the steel pass the ultrasonic flaw detection and meets the requirements for the low-magnification structure, and the cross-sectional acid leaching low-magnification structure test piece of the steel has no visible pinhole defects.

Description

technical field [0001] The invention belongs to the technical field of metal material manufacturing and processing, and specifically relates to a low-carbon structural steel smelting method for preventing pinhole defects in steel ingots, in particular, the main components of the steel are: [C]0.10%-0.25%-[Mn]0.50 %~1.50%-[S]0.020%~0.035%-[Si]0.00%~0.35%-[Cr]0.50%~1.50%-[Ni]0.00%~0.20%-[Al]0.010%~0.040%structure Steel smelting technology. Background technique [0002] The main components of steel grades are: [C]0.10%~0.25%-[Mn]0.50%~1.50%-[S]0.020%~0.035%-[Si]0.00%~0.35%-[Cr]0.50%~1.50% -[Ni]0.00%~0.20%-[Al]0.010%~0.040% Structural steel is a series of low carbon structural steel produced by Baosteel Special Steel Co., Ltd. It is mainly used for processing and manufacturing transmission gear materials such as automobiles and wind power generators. It has certain requirements for the purity of the steel type. After heat treatment, it has good strength, hardness and toughness...

AI Technical Summary

Problems solved by technology

[0008] In order to solve the problem of pinhole defects in the production of low-carbon structural steel ingots, the purpose of the present invention is to provide a method for smelting low-carbon structural steel that prevents the occurrence of pinhole defects in steel ingots. The low-carbon structural steel produced by this method is qualified by ultrasonic flaw detection , to meet the requirements for low-magnification structure, the cross-sectional acid leaching low-magnification structure test piece of steel has no pinhole defects visible to the naked eye

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