Cr12N钢高压凝固行为相图分析研究

Phase Diagrams Analysis of Solidification Process of Cr12N Alloy in High Nitrogen Pressure

结合钢铁数据库FSStel和气相数据库FactPS，利用FactSage软件计算了Fe．Cr-N系在不同氮气压力下的平衡相图，并进行了实验结果对比。研究表明：FSStel数据库结合气相数据可以计算得到与实验结果吻合较好的Fe—Cr-N系高压相图。高压扩大了γ＋δ及γ相区，而gas＋δ相区则缩小（0．1—1．8MPa范围内面积缩小90％，温度区间减dx89％）。随着压力的增大，凝固初期氮的最小溶解度及奥氏体中氮的最大溶解度增加，超过0．6MPa，增速明显降低，且CrN相替代Cr2N相首先稳定析出，高压促进CrN的稳定。高压相图为高氮钢在高压冶金过程中氮的控制提供了指导。

Phase diagram calculations of the Fe-Cr-N system under different pressure of nitrogen gas have been performed using FactSage software and compared with experimental results, combining the FSStel iron steel database and FactPS substances database. The results show a good agreement for the high-pressure solidification experiment with the calculations. High pressure expanded γ＋δ and γ/zone and reduced gas＋8 zone （area reduced by 90% and temperature gap reduced by 89%）. The pressure increases not only the maximum solubility of nitrogen in the phase zone ofaustenite but also the minimum solubility of nitrogen during earlier solidification. But above 0.6 MPa, increasing speed of nitrogen concentration decreases significantly and CrN nitride precipitates firstly instead of Cr2N. High nitrogen pressure promotes the stability of CrN phase. To use high-pressure phase diagrams can be beneficial to the nitrogen control during the process of high-pressure metallurgy.