Build-up welding method for large-diameter thin-wall double-tube plate

Abstract

The invention discloses a build-up welding method for a large-diameter thin-wall double-tube plate. The build-up welding method comprises the following steps: 1) pre-processing, wherein grooves are processed in build-up welding surfaces of two tube plates, and the bottom surfaces of the grooves are tapered; 2) connecting, wherein the two tube plates are fixedly connected into an integer; 3) build-up welding, wherein each tube plate is subjected to build-up welding in layers, build-up welding at each layer is accomplished by two or more local build-up welding processes, and local build-up welding processes of the two tube plates are alternatively performed, first-time local build-up welding process at each layer of each tube plate starts build-up welding from the centre position of the groove, and then performs ring-shaped build-up welding towards the edge in sequence, the rest of local build-up welding processes at each layer of each tube plate perform ring-shaped build-up welding frominside to outside in sequence; and 4) thermal treatment, wherein the integer is fed into a furnace to heat and subject to heat preservation, and each rib plate is dismounted after welding stress is eliminated. The build-up welding method can greatly reduce deformation caused by tube plate build-up welding, avoids follow-up processing, can improve processing efficiency, reduces the cost, and guarantees the thickness of a build-up welding layer very well.

Description

technical field [0001] The invention relates to a surfacing welding method for a large-diameter thin-walled double-plate, in particular to a surfacing method for a large-diameter thin-walled double-tube plate. Background technique [0002] In many large-scale chemical equipment, there are more and more ultra-large thin-walled double-tubesheet projects. Thin-walled double tube sheet equipment has large volume, large diameter and heavy equipment. The diameter of the tube sheet is very large, but the thickness of the tube sheet is very thin, and the diameter-thickness ratio of the tube sheet is very large, and some of the diameter-thickness ratios have reached 25-30. ) In contrast, the rigidity of the tube sheet of this type of large-diameter thin-walled double-tube sheet equipment is very poor. In the process of large-area surfacing welding on the surface of the tube sheet, deformation occurs due to the action of welding residual stress. The deformation direction of the tube...

AI Technical Summary

Problems solved by technology

This method not only has a large thickness of surfacing welding, but also consumes a lot of welding materials, and the thickness of the surfacing welding layer in the central area of ​​the tube plate far exceeds the design requirement of 6mm, which does not meet the design requirements.

Images