Method for producing continuous casting alloy steel containing S and Al

Abstract

The production method of S and Al contained continuous casting alloy steel adopts four-step technological process: (1). smelting steel by using D.C. electric furnace; at the time of tapping (1640-1660 deg.C) adding proper quantity of SiAlFe deoxidant, carbon powder, alloy and slag material; (2) refining by using LF furnace, (a). adding lime (CaO is greater than or equal to 90%), SiFe and C powderin batches, making white slag and bottom blowing argon; (b). for boron-containing steel feeding Ti and retaining B, (c). top slag alkalinity is 2.8, Al2O3 content in the slag is 25%, regulating Al and S; (3) vacuum furnace treatment, its vacuum degree is less than or equal to 140 Pa, and treatment time is 20 min.; and (4) continuous pouring, its pouring speed is 320 kg / min.

Description

technical field [0001] The invention relates to a method for producing alloy steel in the metallurgical industry, in particular to a method for smelting and casting S and Al alloy steel. Background technique [0002] According to the different casting forms of high temperature molten steel, it can be divided into two types: mold casting and continuous casting. Die casting is to pour high-temperature molten steel into steel ingots, which are opened into billets by a roughing mill (or forging press), and the metal yield is low (about 84%); continuous casting is to pour high-temperature molten steel directly into billets, and the metal yield is low. Higher (about 98%). Therefore, the use of continuous casting technology to produce alloy steel can not only greatly increase the metal yield and reduce production costs, but also the development direction of contemporary metallurgical technology. [0003] As we all know: S element in steel is easy to produce sulfide inclusions, wh...

AI Technical Summary

Problems solved by technology

[0004] The production methods of S and Al alloy steels appeared at home and abroad as early as the 1990s. However, there has been no report on the production process technology data about continuous casting so far. understand blank

In recent years, domestic special steel companies have also begun to study the smelting and continuous casting technology of alloy steel containing S and Al. The following difficulties in the steelmaking process have plagued steelmakers: (1) Low oxygen (if the smelting atmosphere is high oxygen conditions, Then the Al alloy added to the steel can only act as a deoxidizer, but cannot enter the molten steel for microalloying-refining grains, and at the same time, the non-metallic inclusions in the steel are difficult to remove

) conditions, the stability of the yield of S element (the yield of S element is unstable, it is easy to cause difficulty in the control of sulfide inclusions, and affect the performance of steel); (2) the level of non-metallic inclusions such as sulfide inclusions (3) Poor castability of molten steel continuous casting (alumina and calcium sulfide inclusions in the steel are easily adsorbed on the inner wall of the submerged nozzle of the tundish, causing the nozzle to be blocked), which may lead to production accidents in severe cases. It is easy to cause the crystallizer liquid level to fluctuate, threatening the quality of the steel