Current Situation and Development of TISCO Nitrogen Stainless Steel

摘要

As a strong austenite former in stainless steel,nitrogen plays an important role on equilibrium and stability of the stainless steel microstructure. As an interstitial element,nitrogen enhances the strength of stainless steel and contributes to the corrosion resistance. In recent years, with the upgrading of the refining facilities, such as AOD and VOD, gaseous nitrogen alloying technology has become optimal. This article describes a nitrogen alloying model developed from the practices of gaseous nitrogen alloying in AOD furnace, TISCO. The model was established with dissolution and removal theories of nitrogen. As a result, the solubility and the nitrogen content in stainless steel product can be predicted and controlled with this model. The major developed nitrogen stainless steel grades include austenitic series and duplex stainless steel series. They have been extensively used in many national crucial projects and industries, such as in auto, petroleum, chemical industry and water conservancy. Nitrogen stainless steel has benefited the users in these fields. This article will also introduce TISCO's plan on the developing of high nitrogen stainless steel in the coming years.