内衬316L复合板压力容器内衬焊缝点蚀问题与对策

摘要

由于对接焊缝与内衬堆焊法兰抗腐蚀性能较低,内衬316L复合板压力容器在氯离子等腐蚀介质的作用下易发生点蚀,影响压力容器的安全运行.为了从根本上解决内衬点蚀问题,针对点蚀只出现在内衬焊缝与堆焊法兰的特点,通过对内衬焊缝采用抗腐蚀性能更高的高钼镍基625盖面,对堆焊法兰采用316L板材贴板,提高了焊缝与堆焊法兰的抗腐蚀性能,较好地解决了点蚀问题,提升了本质安全,有利于双金属复合板压力容器在含腐蚀介质工况下的推广应用.%Due to the low corrosion resistance of the butt weld and the lining overlaying flange, the lining 316L composite broad pressure container is easy to undergo pitting under the action of the chlo-ride ion and other corrosive medium,which affects the safe operation of the pressure container.In or-der to solve the lining pitting problem fundamentally and according to the characteristic that pitting only occurs on the lining weld joint and the overlaying flange,the lining weld joint adopts high nickel-mo-lybdenum based 625 flap surface with higher corrosion resistant performance and the overlaying flange adopts the 316L flitch plate. The above measures can improve the corrosion resistance of the weld joint and the overlaying flange,effectively solve the pitting problem,enhance the intrinsic safety and help to promote and apply the thermometal composite broad pressure container in the working condition with corrosive medium.