Method for producing ultra-low-carbon steel

Abstract

A method for producing ultra-low-carbon steel belongs to steel-making technology field. The process route is: molten iron desulfuration preprocess -converter smelting -RH vacuum process -slab continuous casting. The iron desulfuration preprocess applies blowing magnesium granules for desulfuration; the converter smelting terminal carbon content and oxygen activity of molten steel; applying slag dam operation when tapping without deoxidation; the ladle furnace proceeds operation of top slag modification and temperature controlling; RH vacuum processing to control the maximum vacuum; applying Al for deoxidation when the decarburization is finished, and alloying if the deoxidation is finished and assuring the deep vacuum processing time after the deoxidation; calming the molten steel when the vacuum is finished; applying non-carbon covering agent and non-carbon protection slag in the slab casting process; the continuous casting process uses full protection casting, and the casting process controls a reasonable pulling speed according to slab section. The advantages are: the invention resolves problem of nozzle clogging and improves castability of the ultra-low-carbon steel and implements multi-furnace continuous casting, and the components of carbon, phosphorus, sulphur and nitrogen of the completed product conforms smelting request of the ultra-low-carbon steel.

Description

technical field

[0001] The invention belongs to the technical field of steelmaking, and in particular relates to a method for producing ultra-low-carbon steel, especially realizing stable control of carbon, phosphorus, sulfur and nitrogen content in steel when smelting ultra-low-carbon steel. Background technique

[0002] Ultra-low carbon steel refers to steel with a carbon content below 0.010%. Carbon is the traditional and most economical strengthening element, which can improve the strength of steel through solid solution strengthening, but the increase of carbon content in steel will greatly reduce the ductility and deep drawing performance of steel plate. With the development of industrial demand, the ultra-low carbon microalloying composition design system is adopted, which not only meets the requirements of steel strength performance, but also meets the requirements of other performance aspects.

[0003] Chinese patent 200710159224.7 discloses a method for smelting u...