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研究碳(C)含量为0.05%~0.77%时对18Mn18CrN高氮奥氏体不锈钢750~850℃时效析出行为的影响。结果表明,C含量未改变实验钢中析出方式和析出相类别,Cr2N析出相首先沿晶界以颗粒形貌析出,而后以片层状向晶内生长。随着时效时间的增加,片层状析出相体积分数及片层间隙增加,元素的扩散是控制其长大的主要因素。增加C含量可降低Cr2N相析出孕育时间,增加Cr2N相体积分数,降低Cr2N相扩散激活能,其中QD(A1)=157.63kJ·mol-1;QD(A3)=32.92kJ·mol-1。随C、N含量增加,实验钢中Cr2N相体积分数呈线性趋势增加,但其增加程度更敏感于N含量的变化。
The effect of carbon (C) content from 0.05% to 0.77% on the aging precipitation behavior at 750-850 ℃ for 18Mn18CrN high nitrogen austenitic stainless steel was investigated. The results show that the content of C does not change the precipitation method and the precipitated phase in the experimental steel. The precipitated phase of the Cr2N firstly precipitates along the grain boundaries and then grows into lamellae. With the increase of aging time, the lamellar precipitated phase volume fraction and lamellar spacing increased, and the diffusion of elements was the main factor controlling its growth. The increase of C content can reduce the incubation time of Cr2N phase, increase the volume fraction of Cr2N phase and decrease the activation energy of Cr2N phase diffusion. QD (A1) = 157.63kJ · mol-1 and QD (A3) = 32.92kJ · mol-1. With the increase of C and N content, the volume fraction of Cr2N phase in the experimental steel showed a linear trend, but its increasing degree was more sensitive to the change of N content.