论文部分内容阅读
采用电化学测试技术评价了低碳钢管管端内壁不锈钢焊条堆焊后再用相同焊条进行打底焊所得焊接接头（特别是焊接热影响区）的耐蚀性，选用两种高合金焊条M2、M6，并对堆焊金属进行热模拟试验，测定了模拟热影响区不同部位在3％NaCl介质中的阳极极化行为．结果表明，按新工艺焊接的接头代替普通碳钢焊接接头可有效地提高管道接头的使用寿命．两种焊条中，含Nb的M2耐蚀性比M6好，铌能够有效提高接头的耐均匀腐蚀、晶间腐蚀和点蚀能力，热影响区600～1000℃是高合金接头耐蚀性最薄弱的区域，建议采用超低碳含铌高合金焊条，以解决热影响区的腐蚀问题．
Electrochemical test technology was used to evaluate the corrosion resistance of the welded joints (especially the HAZ) of the welded joints of the inner wall of the mild steel tube after the overlay welding of the inner wall with the same welding rod. Two kinds of high alloy welding rods, M2, M6, and the thermal simulation test of the deposited metal was carried out. The anodic polarization behavior of different parts in simulated heat-affected zone in 3% NaCl medium was measured. The results show that, according to the new process of welding instead of ordinary carbon steel welded joints can effectively improve the service life of pipe joints. Among the two electrodes, the corrosion resistance of Nb-containing M2 is better than that of M6. Niobium can effectively improve the uniform corrosion resistance, intergranular corrosion and pitting corrosion resistance. The heat-affected zone is the weakest corrosion resistance of high-alloy joints at 600 ~ 1000 ℃. Of the region, it is recommended to use ultra-low carbon niobium high alloy electrode, to solve the corrosion problem in the heat affected zone.