P92 steel is new emerging ferritic heat-resisting steel.Up to now,the welding joints of P92 steel pipes have been all repaired in China by the matching welding materials~ After welding,additional heat treatment is required.However,muhiple times of heat treatments lead to degradation in performance of the pipe wall and take a lot of time and cost.A series of experiments were carried out by our company on repairing the welding joints of P92 steel pipes.We operated welding procedures adopted in site construction using nickel-based welding materials,in case of the matching welding materials are not available during the temporary repair.We avoided heat treatment after repairing thus the effect of multiple thermal cycles on the performance of the tube was avoided and several performances were operated.The experiments showed the following results:the welding joint tensile experiment using the nickel-based alloy after weld repairing was eligible,and the unknown fracture was in parent material;the hardness values of the weld,heat affected zone and base metal met the requirements;the impact value of weld and heat affected zone met the requirements;metallographic structure was eligible.As a conclusion,it is feasible to use nickelbased welding materials for temporary repair,but further study is needed on its high temperature aging performance and the long-term strength performance.%P92钢是新型铁素体耐热钢,目前国内采用其匹配焊材进行返修,焊后需进行再次热处理,而多次热处理会造成管壁的性能下降,且需要花费大量的时间和成本.在临时性返修没有匹配焊材的情况下,采用镍基焊材进行P92钢管焊口返修,返修后免做热处理,避免多次热循环对管子性能的影响,然后进行各项性能试验.结果表明,返修后的焊接接头拉伸试验合格,断裂位置位于母材;焊缝、热影响区、母材的硬度值符合规定要求;焊缝、热影响区的冲击值符合规定要求;金相组织合格.试验证明,采用镍基焊材进行临时性返修试验是可行的,但对于高温时效性能及持久强度性能,还需要进一步研究.
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