焊后热处理对CLAM钢焊接接头耐液态铅铋合金空泡腐蚀性能的影响

加速器驱动次临界系统的冷却剂液态铅铋共晶合金在循环管道中高速流动时会对主泵叶轮及第一壁包层材料造成空泡腐蚀.焊接接头是整个循环管道中的薄弱环节，但合理的焊后热处理是提高循环管道中焊缝区域性能最有效的方法.自主设计一套装置用于金属溶液空泡腐蚀试验.对各组试样不同时间空泡腐蚀后的表面形貌、粗糙度、空蚀坑平均深度进行分析，再结合焊后热处理后的焊缝微观组织及力学性能，对空泡腐蚀行为及耐空蚀性能提高机制进行分析.结果表明，调质后焊缝耐空蚀性能最好；760℃回火后耐空蚀性能也比较好；710℃与810℃回火后耐空蚀性能稍差；未焊后热处理焊缝耐空蚀性能最差.

Effect of PWHT on cavitation erosion resistance of CLAM weld joint in liquid Lead-bismuth eutectic alloy

The coolant liquid lead-bismuth eutectic alloy (LBE) of the accelerator driven subcritical reactor system (ADS) would lead to serious cavitation erosion on the main pump impeller and the first wall cladding material when the liquid LBE flows at a high speed. Welding joint is the weak area in the whole circulation pipeline, and the reasonable heat treatment is the most effective method to improve the performance of the weld area. A suit of ultrasonic cavitation facility was self-designed to the cavitation erosion test. By analyzing the surface topography, roughness and mean pit depth of specimens after being eroded for different time, and combining these erosion results with the microstructure and mechanical properties of weld bead after PWHT, the cavitation behavior of weld bead of CLAM steel after PWHT and the influence of PWHT to the cavitation behavior of weld bead were studied. The results show that the weld bead being quenched and tempered showed the best cavitation erosion resistance. The cavitation erosion resistance of weld bead after being tempered at 760℃ were better than that of weld bead after being tempered at 710℃ or 810℃. The weld bead without PWHT exhibited the poorest cavitation erosion resistance.