A kind of smelting method of low-manganese and low-phosphorus steel

Abstract

The invention provides a smelting method of low manganese and low phosphorus steel, and the method is as follows: loading low manganese and low phosphorus steel scrap containing not more than 0.5% manganese and not more than 0.04% of phosphorus when in a smelted state and pig iron into an electric furnace, adding iron oxide scale with the amount of 0.5% of the total amount of the steel scrap and the pig iron; after the steel scrap is basically smelted, performing sampling and analysis, adding lime and fluorite, after the basicity of slag is controlled, performing slagging and replacing the slag; when manganese content in molten manganese is less than or equal to 0.04%, performing sampling and analysis on the slag, adding the lime and the fluorite, and after the slag is melted, performing slag flowing; when phosphorus content in the molten steel is less than or equal to 0.002%, performing steel tapping, adding the lime and the fluorite according to the amount of the molten steel; putting a steel ladle into a refining furnace, and when the temperature in the refining furnace reaches 1620 DEG C, clamping the slag and performing ladle mixing to allow the manganese content in the moltenmanganese to be not more than 0.05% and the phosphorus content in the molten steel to be not more than 0.004% when in steel tapping. The method can control the manganese content in the molten manganese to be not more than 0.05% and the phosphorus content in the molten steel to be not more than 0.005%, so that the melted steel and a cast steel ingot have excellent performance.

Description

technical field [0001] The invention relates to a smelting method, in particular to a smelting method of low-manganese and low-phosphorus steel. Background technique [0002] Mn and P are common elements in steel. Mn element can improve the yield strength and tensile strength of steel, and has always existed as a beneficial element. Almost all steel types contain a certain amount of manganese. However, in grain-oriented silicon steel, Mn element It will form the second phase particles, interfere with the orientation of {110} and <001> in the steel structure, hinder the formation of a single Gaussian texture in the steel, and affect the magnetic properties of the steel; in ultra-pure Cr-Ni-Mo-V rotor steel Among them, the Mn element will strengthen the segregation of phosphorus P at the grain boundary, cause the increase of P concentration at the grain boundary, increase the value of FATT, amplify the embrittlement of P, and affect the performance of the steel. In thes...

AI Technical Summary

Problems solved by technology

[0003] Demanganization requires a strong oxidizing atmosphere. Due to the furnace type characteristics of the converter, the oxidizing atmosphere is good, and the thermodynamic and kinetic conditions for demanganization are good. Therefore, traditionally, low manganese steel is generally produced by the converter. For example, the Chinese patent disclosure No. CN106811567A discloses a production method of low-manganese steel. By controlling the lance position and alkalinity of the oxygen lance of the converter, supplemented by stirring and raising the temperature of the refining furnace to make slag, the low-manganese steel with an end point Mn≤0.025% can be produced. Electric furnace and converter There is a large difference in the environment, and the process of the converter cannot be applied to the operation of the electric furnace. For the production of low-manganese and low-phosphorus steel in the electric furnace-refining furnace, there is no clear literature or patent technology in China.