对某超临界锅炉运行 7.5 万小时的T91/TP347H异种钢接头,采用金相显微镜、万能材料试验机和扫描电镜等仪器设备,研究长时服役后T91/TP347H异种钢接头的性能.结果表明:该异种钢接头薄弱区在T91 熔合线处,该位置链状孔洞和脱碳层的形成大大弱化了力学性能,氧化缺口的形成加速了接头的开裂.异种钢接头各区域的冲击性能显著降低,其中焊缝冲击性能最低,实测仅为 66 J.
Performance of T91/TP347H Dissimilar Steel Welded Joint of Supercritical Boiler after Long-term Service
For T91/TP347H dissimilar steel joints of a supercritical boiler operating for 75,000 h,the metallographic microscope,the universal material testing machine and the scanning electron microscope were used to study the performance of the joint after long-term service.The results show that the weak area of the dissimilar steel joint is at the T91 fusion line,the formation of chain holes and decarburization layer in the region greatly weaken the mechanical properties,and the formation of oxidation gap accelerates the cracking of the joint.The impact performance of each area of the dissimilar steel joint is significantly reduced,and the impact performance of the weld metal is the lowest,which is only 66 J.
dissimilar steel jointT91TP347Hdecarburization layerlong-term service
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万方数据
