Method for producing high-purity stainless steel

Abstract

The invention relates to a method for producing a high-purity stainless steel. The method comprises the following steps: molten raw materials are put in an argon oxygen decarburization (AOD) refining furnace to be decarburized, reduced and desulfurized, so that molten steel is obtained; then the molten steel is delivered to a steel ladle; and the molten steel is continuously cast, wherein the treatment of the AOD refining furnace comprises the following steps: after the oxygen blowing decarburization is finished, ferrosilicon is put, meanwhile, slagging and desulfurizing are carried out, the desulfurizing is finished until the S content in the furnace is smaller than 0.01wt%, steel is tapped into the steel ladle from the AOD refining furnace for the first time, after the steel ladle is slagged off, the molten steel is added into the AOD refining furnace again to be slagged again, oxygen is blown, the slag basicity is controlled within the range of 1.4-1.8, argon is then blown, the molten steel is stirred until the S content in the furnace is smaller than 0.01%, and the steel is tapped from the AOD refining furnace again so as to obtain the molten steel. The method adopts the AOD refining furnace, a double-slagging method is adopted, and hard slag inclusions are prevented from being produced, and thus, the high-purity stainless steel is produced.

Description

technical field [0001] The invention relates to a method for preparing high-purity stainless steel, which belongs to the field of stainless steel smelting. Background technique [0002] Known by prior art documents, such as CN1524968A Figure 1a and Figure 1b As shown, when there are hard inclusions in the stainless steel, the surface of the prepared cold-rolled steel coil will have the defects shown in the figure. This is due to the fact that these inclusions do not have deformability at low temperatures and can cause surface defects or cracks during cold rolling. CN1524968A's figure 2 is a graph showing the relationship between spinel formation rate and surface defect index in cold rolled coils. Among them, spinel formation rate (%) = number of spinel inclusions / number of all observed inclusions × 100, surface defect index = number of linear cracks caused by inclusions / 1km cold-rolled steel coil. Such as figure 2 As shown, the surface defects of cold-rolled ste...

AI Technical Summary

Problems solved by technology

This method will reduce the use of low-priced raw materials and increase the cost of raw materials. Moreover, there are many sources of sulfur in raw materials, and the control is very unstable. High sulfur in raw materials often leads to excessive sulfur in products.

Images