SA-335P11 and SA-240TYPE310S dissimilar steel welding and heat treatment method

Abstract

The invention discloses a welding and heat treatment method for SA-335P11 and SA-240TYPE310S dissimilar steel. The welding and heat treatment method comprises the following steps: A, preparing before welding; b, a groove is machined and cleaned; c, surfacing the nickel alloy isolating layer, and performing stress relief heat treatment on the nickel alloy isolating layer and a workpiece heat affected zone; d, preparation before assembly; E, assembly and tack welding are conducted on the first workpiece and the second workpiece; f, backing welding is conducted on the root of the groove through manual argon tungsten-arc welding; g, filling the cover surface by adopting manual arc welding; h, polishing and removing welding lines on the inner and outer surfaces of the deposited metal, polishing and removing undercuts at weld toes, and ensuring smooth transition between the deposited metal and the inner and outer surfaces of the workpiece; i, welding seam VT inspection; j, weld PT detection; and K, welding seam RT detection. According to the welding and heat treatment method, the isolating layer is welded on the first workpiece, so that the process technical requirements of stress relief heat treatment of the SA-335P11 material are met, and accelerated sensitization of the SA-240TYPE310S material is avoided.

Description

technical field [0001] The invention relates to a welding and heat treatment method for dissimilar steel materials, in particular to a welding and heat treatment method for welding SA-335 P11 and SA-240TYPE310S dissimilar steel materials. Background technique [0002] At present, in the petrochemical industry, some process pipes or plates are made of two different steel materials. Due to the different materials of the steel materials, such as SA-335 P11 high-temperature alloy chromium molybdenum steel material and SA-240TYPE310S austenitic stainless steel material, these two When the materials need to be welded together, the welding and heat treatment technology is very difficult, and the quality requirements are high, especially the welding technology of the petrochemical plant process pipeline of dissimilar steel with large diameter and thick wall is more difficult and the process is more complicated. High requirements for temperature, interpass and interlayer temperature,...

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Problems solved by technology

[0002] At present, in the petrochemical industry, some process pipes or plates are made of two different steel materials. Due to the different materials of the steel materials, such as SA-335 P11 high-temperature alloy chromium-molybdenum steel material and SA-240TYPE310S austenitic stainless steel material, these two When the materials need to be welded together, the welding and heat treatment technology is very difficult and the quality requirements are high, especially the welding technology of petrochemical plant process pipes of dissimilar steel with large diameter and thick pipe wall is more difficult and the process is more complicated. High requirements for temperature, inter-pass and inter-layer temperature, and heat input, large amount of weld deposit metal filling, long working cycle, and high requirements for welder operation skills make it impossible for conventional welding and heat treatment methods to complete the welding work.

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