Butt welding flanges are widely used, with corresponding rigidity and elasticity requirements and reasonable butt welding thinning transitions. The distance between the welding joint and the joint surface is large, and the joint surface is protected from welding temperature deformation. For pipelines with large fluctuations in pressure or temperature or pipelines with high temperature, high pressure and low temperature, it is generally used for the connection of pipelines and valves with a PN greater than 2.5MPa; it is also used for pipelines that transport expensive, flammable and explosive media. Next, the defects and solutions of butt welding flanges will be introduced by dual-energy butt welding flange manufacturers.
Defects of butt welding flange welding
The welding seam of the flange has serious flaws. If it is supplemented by manual mechanical grinding, the resulting grinding marks will cause uneven surface and affect the appearance;
Uneven grinding, polishing and passivation: After manual grinding and polishing, pickling and passivation is carried out. For workpieces with large areas, it is difficult to achieve the same uniform treatment effect, and an ideal symmetrical surface cannot be obtained. There are also its shortcomings: labor costs, and material costs are also high.
The overall pickling passivation will cause chemical corrosion or electrochemical corrosion to rust in the presence of corrosive media, and it cannot remove carbon steel, spatter and other impurities adhering to the stainless steel surface due to scratches and welding spatter.
Butt welding flange defect solution
1. Select blanking, after completion, enter the next process, different workpieces of stainless steel enter the relative process according to the processing requirements;
2. When bending, first of all, according to the size on the drawing and the thickness of the stainless steel material, determine the tool and kerf used for bending. Avoiding the deformation caused by the collision between the product and the tool is the key to the selection of the upper die (in the same product, it may be Different types of upper molds are used), and the selection of lower molds is determined according to the thickness of the sheet.
3. In order to weld firmly, make bumps on the workpiece to be welded, so that the bumps can be evenly contacted with the plate before electric welding, so as to ensure the uniform heating of each point, and at wholesale storz coupling manufacturers the same time, the welding position can also be determined. Good pre-pressing time, holding time, maintenance time and rest time to ensure that the workpiece can be spot welded firmly.