高纯Fe-0.2%P-2%Cr-C合金晶界的高分辨俄歇能谱分析

High Resolution Auger Electron Spectroscopy Analysis on Grain Boundaries of High Purity Fe-0.2%P-2%Cr-C Alloys

利用高分辨俄歇能谱仪研究了高纯Fe 0 2 %P 2 %Cr C合金的晶界·结果表明 ,沿晶断面上有大量尺寸约 0 3 μm的颗粒状碳化物·碳化物处碳的PHR值分别为 3 4 9%和 3 3 3 % ,铬的PHR值为 1 4 6%和 7 3 % ,碳化物为富铬碳化物 ;晶界上无碳化物处存在显著的磷偏聚和碳偏聚 ,磷的平均偏聚量分别为 2 0 2 %和 1 9 6% (PHR) ,晶界富集系数为 5 6和 5 4,碳的PHR值分别为 8 6%和 1 2 6% ,晶界富集系数为 3 0 8和 45 0 ;随合金碳量增加 ,碳在晶界偏聚量增加 。

The grain boundaries in high purity Fe-0 2%P-2%Cr-C alloys were analyzed by high resolution Auger electron spectroscopy. The results show that a large number of carbides in 0 3?μm average diameter exist at intergranular fracture surfaces. PHRs (Peak Height Ratio) of carbon at the boundary regions with carbides are 34 9% and 33 3% for two alloys, respectively, and the PHRs of chromium are 14 6% and 7 3%. The carbides are identified as chromium rich carbides. Remarkable segregation of phosphorus and carbon takes place at grain boundary regions without carbides. The segregation levels (PHR) of phosphorus at the boundary regions without carbides are 20 2% and 19 6% for two alloys, respectively, and its enrichment factors are 56 and 54. The PHR values of carbon at the regions are 8 6% and 12 6% for two alloys, respectively, and its enrichment factors are 308 and 450. With increase in carbon content in the alloy, carbon segregation is increased, while phosphorus segregation is slightly decreased.