典型异质钢接头碳迁移与高温力学性能

针对A102焊接典型异种接头的碳迁移现象以及高温力学性能进行研究,利用由菲克定律推导出的碳扩散理论计算公式对扩散过程进行计算并绘制理论曲线.通过碳的成分分析绘制出实际碳扩散曲线,对熔合线两侧的组织进行观察.结果表明:理论碳扩散曲线与实际碳扩散曲线基本相同.对于A102焊接的15Cr MoR珠光体耐热钢与316奥氏体不锈钢异质钢接头而言,熔合线的不锈钢焊缝金属一侧出现增碳层,组织主要为碳化物和马氏体,而15Cr MoR热影响区一侧出现脱碳层,组织主要为铁素体.蠕变试件在熔合线脱碳层附近发生断裂,断裂方式为韧窝断裂.

Carbon migration and high temperature mechanical properties of typical dissimilar steel joint

The carbon migration and high temperature mechanical properties of typical dissimilar steel joint welded with A102 were studied. With the carbon diffusion calculation formula derived on the basis of Fick’s law, the diffusion process was calculated and the theoretical curve was drawn. Through the analysis on the carbon content, the actual carbon diffusion curve was drawn, and the microstructures on both sides of fusion line were observed. The results show that the theoretical carbon diffusion curve is basically the same as the actual carbon diffusion curve. For the 15CrMoR heat resistant steel and 316 austenitic stainless steel joint welded by A102, the carburized layer appears near the fusion line on the side of stainless steel, and the microstructure is mainly carbides and martensite. In addition, the decarburization layer appears in the heat affected zone of 15CrMoR, and the microstructure is mainly ferrite. The fracture of creep specimens occurs near the decarburization layer near the fusion line, and the fracture mode is dimple fracture.