A method for reducing the nitrogen content of electroslag ingot

Abstract

The invention relates to a method for reducing the nitrogen content of electroslag ingot. The method comprises the steps as follows: nitrogen removal performed during smelting: waste steel is filled in an electric arc furnace and electrified for smelting, oxygen is blown for accelerating smelting after a smelting cell is formed in the electric arc furnace, and foam slag is produced by a furnace door carboxyhemoglobin gun after waste steel in the furnace is cleared; production of refined white slag: the pressure of argon is regulated, steel ladle bottom argon blowing agitation is strengthened, and gas in steel continuously floats upwards and is exhausted; sampling and nitrogen analysis: the nitrogen content is surely controlled below 45 ppm; when a self-consuming electrode is cast, an argon protective ring with more small air holes is welded below a water port, and the argon is introduced to form a gas curtain, a steel flow is located in the gas curtain, air is effectively isolated by the gas curtain, and the nitrogen absorbed by the steel water from the air can be reduced; arranging of a smoke hood for the electroslag furnace: the argon is introduced into the smoke hood during the smelting, and a protection atmosphere is formed and absorbed nitrogen is reduced; adding of deoxidant into the furnace slag in patch for deoxidation. The method can effectively reduce the nitrogen content of the electroslag ingot, the production operation is stable, the requirement on the quality of the finished product can be met, and the nitrogen content of the electroslag steel ingot is basically less than 100 ppm.

Description

technical field [0001] The invention relates to a method for reducing the nitrogen content of an electroslag ingot. Background technique [0002] Electroslag steel ingots are mainly used for roll steel. Roll steel has very strict mechanical performance requirements, and the requirements for composition and flaw detection are strictly controlled. The harmful gas nitrogen in the steel not only reduces the mechanical properties of the steel, but also makes the steel produce hair. Defects such as grains and subcutaneous air bubbles will cause the steel to be scrapped. At present, the nitrogen content of steel for rolls is required to be controlled below 130ppm. As the market's requirements for product quality increase, the requirements for nitrogen content in electroslag steel ingots are also very stringent, and it is necessary to further reduce the gas nitrogen content in steel. [0003] The production links of electroslag ingots mainly include: smelting in electric furnaces ...