Method for controlling tailor welding deformation of large metal pipe plate

Abstract

Disclosed is a method for controlling tailor welding deformation of a large metal pipe plate. The diameter of the large metal pipe plate ranges from 5,000 mm to 10,000 mm, and the thickness of the large metal pipe plate ranges from 60 mm to 400 mm. GB150.2 steel plates are adopted as materials for tailor welding. A pipe plate blank is formed by two to three steel plates in a tailor welding mode, asymmetric narrow-gap U-shaped grooves are adopted in welding grooves, the size R of the grooves is equal to 10 mm to 12 mm, and welding fusion quality and back gouging can be improved conveniently. The depth t1 of the upper groove is 8 mm to 10 mm larger than that of the lower groove, and after back gouging, welding joints of the upper groove and the lower groove are filled with basically-identical metal. The root face t2 of the grooves is equal to 1 mm to 3 mm, the angle alpha of the grooves ranges from three degrees to five degrees, the root clearance j is equal to 0 mm to 2 mm, and therefore the filling amount of welding metal is reduced. According to the method, tailor welding deformation of the pipe plate can be controlled precisely, and the metal consumption amount of the pipe plate blank is reduced.

Description

technical field [0001] The invention relates to a method for controlling tailor-welding deformation of large metal tube sheets, which is used for making metal tube sheet blanks of large reaction vessels and heat exchangers in petroleum and chemical industries. Background technique [0002] For large vessels, especially large reaction vessels, due to the requirements of the production process and the influence of medium, temperature and pressure factors in the vessel, the diameter of the tube sheet of the large vessel is 5 000 mm to 10 000 mm, and the thickness is 60 mm to 400 mm. Taking the key equipment of the 50,000 tons / year maleic anhydride plant—the tubular fixed tubesheet reactor as an example: the diameter of the upper and lower tubesheets of the reactor is φ6 000 mm, the thickness is 140 mm, and the material is Q345R (normalizing) steel. The flatness tolerance of the plate is ≤3mm, and there are 26180 reaction tube holes on each tube plate. Since the diameter of the...

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Problems solved by technology

Patent 201010153786.2 adopts the method of installing a fixed bracket on the tube sheet blank. During the heat treatment process, as the temperature rises, the rigidity of the rigid bracket also decreases due to the increase in temperature, and the effect of eliminating welding deformation and welding stress is reduced; patent 200810018212.7 The super-large tube sheet thermal leveling method introduces a heat treatment method after tailor welding of large tube sheets. The largest deformation is mainly at the weld in the middle of the tube sheet; from the implementation of the patent: the tube sheet specification is φ4 936㎜, the thickness is 90㎜, the material is 16MnR (Q345R), and the tube sheet blank adopts 2 pieces of 2 500×5 000×110㎜ steel plate tailor welding, according to the disclosed method, the measured results after heat treatment: the unevenness before heat treatment is 36㎜, the unevenness after heat treatment and leveling is 24㎜, the leveling of the deformed tube plate The effect is not high. The tube plate with a thickness of 90 mm is tailor-welded with a 110 mm steel plate, and the machining allowance of the tube plate blank is 20 mm, which increases the metal consumption and processing cost, which is very uneconomical.

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