冷凝器管板N10276合金带极埋弧堆焊工艺研究与应用OA

To investigate the feasibility of strip submerged arc surfacing technology for surfacing N10276 corrosion-resistant layer on the tube sheet of a large-diameter heat exchanger,a nickel-based alloy N10276 surfacing process test was carried out taking the condenser 16MnⅢ tube sheet(⌀2 430 mm×60 mm)serving in a strong chlorine corrosion environment of a chemical plant as the research object.A strip submerged arc surfacing scheme using H276 strip with SJ86B flux was adopted.Through optimizing the welding parameters of the transition layer and the corrosion-resistant layer,and implementing supporting process measures such as preheating at larger than 80℃,low heat input(transition layer≤1.78 kJ/cm2,corrosion-resistant layer≤1.73 kJ/cm2),and strict interpass temperature control(transition layer 100～200℃,corrosion-resistant layer≤100℃),the stress relief heat treatment of the transition layer was completed and systematic procedure qualification was carried out;the surfacing layer was subjected to non-destructive testing,chemical composition analysis,electrochemical testing,intergranular corrosion testing,and comparative testing of bending performance before and after corrosion.The test results show that the electrochemical corrosion behavior of the surfacing layer is comparable to that of the N10276 raw material,and the intergranular corrosion rate is 9.3 mm/a,which meets the requirement of corrosion rate≤12 mm/a in the equipment manufacturing technical documents;no defects such as cracks appeared in the bending tests before and after corrosion.The research shows that by adopting this process,a surfacing layer with corrosion resistance comparable to that of N10276 raw material can be obtained on a large-diameter tube sheet of 16MnⅢmaterial.The process scheme is feasible and can provide an engineering reference for the preparation of nickel-based alloy corrosion-resistant layers on similar large-diameter tube sheets.