Smelting method for titanium-containing austenitic stainless steel

Abstract

A smelting method for a stainless steel containing Ti austenite, which is to add the molten steel after refining of AOD into an LF refining furnace to refine. The procedures are as follows: 1) after the molten steel is added to the LF furnace, lime, fluorite and aluminum are added in to modify slag; 2) after slag modification, the FeNb is added in and the adding amount is to make the Nb be 0.10 to0.20 percent of the molten steel; 3) 4m / t calcium-silicon wire is fed at 1540DEG C; 4) the FeTi is added in, and the adding amount is to make the Nb be 0.10 to 0.15percent of the molten steel and make sure that (0.5Nb+Ti) is more than or equal to 6C, and stir; 5) the molten steel outgoes when the components (weight percent) reach the following values: C less than or equal to 0.04percent, Si0.40 to 0.70percent, Mn0.80 to 1.50percent, P: less than or equal to 0.030percent, S: less than or equal to 0.005percent, Ni17.02 to 17.80percent, Cr9.02 to 9.15percent, N: less than or equal to 0.015percent, (0.5Nb+Ti) more than or equal to 6C, and the rest is Fe and unavoidable impurities, and is cast into a cast ingot. The smelting method for a stainless steel containing Ti austenite has low technological difficulty, is easy to mater and low in waste rate.

Description

technical field [0001] The invention relates to a method for smelting titanium-containing austenitic stainless steel. Background technique [0002] Ti-containing austenitic stainless steel has excellent corrosion resistance and excellent comprehensive mechanical properties in various corrosive media, and is widely used in various chemical and light industry fields. Ti-containing austenitic stainless steel varieties have a domestic market share of more than 90%. The steel types mainly include 1Cr18Ni9Ti, 0Cr18Ni10Ti, SUS321, and X6CrNiTi18-10. The chemical composition of the finished products is shown in Table 1. [0003] Table 1 [0004] [0005] In order to prevent intergranular corrosion of austenitic stainless steel during use, a certain amount of Ti is added to this type of steel to stabilize C in the steel. However, Ti has a strong affinity with nitrogen and oxygen, and TiN and TiO are easily formed in molten steel during smelting and continuous casting. 2 inclusi...

AI Technical Summary

Problems solved by technology

The existing method is to use the Ti single stabilization process to produce Ti-containing austenitic stainless steel. This method has very strict requirements on the production process, is difficult to master, and is difficult to produce. A slight negligence may result in waste products due to inclusions on the product surface.

Since Ti-containing austenitic stainless steel continuous casting slabs are prone to inclusion defects, the surface quality is poor, and the proportion of scrap is high, the billet must be carefully ground before rolling to remove subcutaneous inclusion defects on the surface, resulting in a large amount of grinding work , much metal loss

Images