Method of temperature control and chromium preservation in rh decarburization process of ultra-low carbon high chromium steel

Abstract

The invention discloses a temperature-controlling chrome-protecting method for an ultra-low carbon high chrome steel RH decarbonization process. The temperature-controlling chrome-protecting method for the ultra-low carbon high chrome steel RH decarbonization process comprises the following steps of S1, setting the RH feeding molten steel temperature to be 1605 to 1625 DEG C, enabling molten steelto contain the following chemical components in percentage by mass: 0.05 percent to 0.5 percent of Si, 0.5 percent to 2.0 percent of Mn, 5 percent to 15 percent of Cr, and 0.1 percent to 0.35 percentof C, and vacuumizing after a steel ladle is put in place; blowing oxygen, decarbonizing, and the like. The temperature-controlling chrome-protecting method for the ultra-low carbon high chrome steelRH decarbonization process provided by the invention has the advantages that after RH oxygen blowing and decarbonizing are finished, the C content reaches to the target ingredient, the oxidation lossof the Si and the Mn in the molten steel is lower than 15 percent compared with RH feeding, and the content of the Cr element is reduced to be smaller than 0.5 percent.

Description

Technical field [0001] The invention relates to the technical field of steelmaking, in particular to a temperature control and chromium preservation method for ultra-low carbon high chromium steel RH decarburization process. Background technique [0002] When iron and steel enterprises organize the production of high-chromium alloy steel, they generally choose to adopt the stainless steel smelting process route, namely EAF+AOD or VOD method, mainly EAF+AOD. The process route is short and the investment cost is low. There are many steel enterprises specializing in the production of stainless steel. Use this process route. Another smelting method is EAF + converter (MRP, K-OBM or LD-OB) + VOD method. Due to the VOD, this process can more easily smelt ultra-low carbon and nitrogen stainless steel. [0003] Accordingly, when smelting high chromium steel with Cr content ≥5%, the smelting process of stainless steel can be used to organize production. However, for most non-production st...

AI Technical Summary

Problems solved by technology

However, for most non-production stainless steel enterprises, the production is mainly based on the BOF→LF / RH→CC process route. It is difficult to achieve high-alloy and ultra-low-carbon smelting in RH vacuum furnaces. On the one hand, if Cr is controlled before deep decarburization In place, due to the high Cr content, severe oxidation of Cr is prone to occur in the deep decarburization stage of RH, and the loss of Cr alloy is large; It is difficult to control the temperature of molten steel. It is difficult to meet the smelting requirements by increasing the temperature of molten steel entering the RH station. The RH treatment process requires a large amount of aluminum and oxygen blowing to raise the temperature. If the RH entering station temperature is too high or the temperature compensation during the smelting process is too high, the refractory material will be damaged. In addition, due to the large amount of chromium alloy added, it brings serious carbon return problems, and it is difficult to realize the smelting of ultra-low carbon and high chromium steel

[0004] In view of the above problems, iron and steel enterprises that generally use the BOF→LF / RH→CC process route basically do not produce ultra-low carbon, high-chromium alloy steel or other high-alloy steel. Therefore, for C content less than 0.015%, Cr content greater than 5% ultra-low carbon high alloy steel rarely reported