Electric furnace manganese alloying method used during smelting of stainless steel

Abstract

The invention relates to an electric furnace manganese alloying method used during smelting of stainless steel. The method comprises the following steps that I, light and thin nickel stainless waste steel, chromated nickel pig iron containing Si greater than or equal to 1.5%, high-carbon ferro-chrome, manganese oxide ores containing manganese being 35-50% and stainless steel slag are added onto an electric furnace for mixing, and the added quality of the manganese oxide ores is 20 kg / t-40 kg / t; II, after the materials are added, the electric furnace is powered on for melting the materials, and lime is added in batches; after the materials get red, a consumable oxygen lance starts to blow oxygen for melting acceleration and stops blowing oxygen when the oxygen consumption of the total oxygen blowing quality reaches 5-8 Nm3 / t; III, lime is added in the converting process, the slag alkalinity is controlled within the range of 1.3-1.7; slag is blown through oxygen and stirred, the electric furnace is powered off after the materials in the furnace are melted completely, and finally, temperature measurement, sampling and tapping are conducted; and IV, after tapping of the electric furnace, slagging-off is conducted in the slagging-off position, molten steel is added for refining during AOD, silicon iron and silicomanganese are used for reduction, and then tapping is conduced. By means of the electric furnace manganese alloying method used during smelting of stainless steel, the manganese alloying cost is low, and the oxygen consumption is little.

Description

Technical field [0001] The invention relates to a method for manganese alloying in an electric furnace, in particular to a method for manganese alloying in an electric furnace when smelting stainless steel. Background technique [0002] Manganese is a beneficial element in steel, part of which is dissolved in ferrite (or austenite), and part of which forms alloy cementite. Manganese can significantly improve the hardenability of steel, and has a certain solid solution strengthening effect on the matrix. In the range of low content, it can improve the strength, hardness and wear resistance. In the range of high content, it is the main austenitizing element . Ferromanganese alloy is an indispensable alloy in the steelmaking process. [0003] Nickel-series stainless steel contains a certain amount of manganese, which can stabilize austenite in stainless steel, and 304 series stainless steel contains ≤2.0% manganese. In the stainless steel production process, a certain amount...

AI Technical Summary

Problems solved by technology

Generally, there are two adding methods: one is to add high-carbon ferromanganese in the electric furnace or in the early stage of AOD. High-carbon ferromanganese contains about 8% cC and 0.2% P, which will increase the P content during the smelting process. Stainless steel smelting The process cannot dephosphorize, which reduces the dosage of chromium-nickel pig iron, and the cost is high

The second is to add silicon-manganese or electrolytic manganese for alloying during AOD reduction. Silicon-manganese contains a certain amount of carbon, which requires deep decarburization in the early stage of AOD to further reduce the carbon content in the steel. Adding electrolytic manganese will lead to an increase in smelting costs.

In short, stainless steel AOD uses high-manganese, electrolytic manganese and other precious manganese alloys for manganese alloying, which has high cost and high oxygen consumption during electric furnace melting.