A method for predicting nitrogen gas pores in nitrogen alloying stainless steels

A method for prediction of nitrogen gas pores in nitrogen alloying stainless steels was proposed with combining experimental and calculated results. The critical nitrogen content defined as maximum nitrogen content without nitrogen gas pores was experimentally determined. The critical nitrogen content was converted to the critical nitrogen partial pressure with considering segregation of other alloying elements calculated by Thermo-Calc to predict the critical nitrogen content with different Mn levels. The predicted critical nitrogen content agreed favorably with experiments. This method can be used to predict the maximum amount of dissolved nitrogen permissible in the melt in order to avoid the formation of nitrogen gas pores.