Solubility of Nitrogen in Fe-Cr-Ni-Mo Stainless Steel

摘要

Solubility of nitrogen in liquid Fe-Cr-Ni-Mo stainless steel was measured in the temperature range from 1723 to 1923 K under a N2 gas of 1 atm.As a result,the solubility increased with increasing Cr,Mo and Mn content,whilst it decreased with increasing Ni content.In addition,the solubility increased with decreasing temperature.Thermodynamic analysis was carried out taking Fe-20 mass％ Cr alloy.The first attempt showed that the calculated solubility,applying the reported first-order interaction coefficients of N against Cr,Ni,Mo and Mn,did not agree with the measured values.This inconsistency was found to be attributed to the interaction coefficient of N against Ni ( Fe20Cr Ni eN ).Therefore,this value available up to 30 mass％ Ni has been reassessed.Thereby the corresponding coefficient was derived as 0.0063 with which the solubility could be well predicted.