Method for preventing deformation of large-size thin-wall annular casting during welding process

Abstract

The invention relates to a method for preventing deformation during a welding process, in particular to a method for preventing the deformation of a large-size thin-wall annular casting during the welding process. The method is characterized in that the method comprises the following steps of: preparation before welding: preparing a shim plate used for supporting at least five points of the casting so as to ensure that the casting is padded flatly and cannot be deformed by external forces during the welding, and an anti-deformation welding tooling, and then fixing the casting on the tooling; pre-heating before welding; selection of parameters of the welding process; and control of the welding process. The method provided by the invention is unique; the quality of the casting can be ensured; the production cycle can be shortened; the working efficiency can be improved; and the production cost can be saved.

Description

technical field [0001] The present invention relates to a method for preventing deformation during welding, in particular to a method for preventing deformation during welding of large-scale thin-walled ring castings. Background technique [0002] For large-scale thin-walled ring castings, the outline size is 4000-10000mm, the minimum wall thickness is 20-80mm, and the cross-sectional shape is complex. Ring castings have a large diameter span, especially the material is low carbon steel, and the material strength is between 300 and 500 MPa. A series of deformation problems are prone to occur during the defect welding process, mainly in the following aspects: size opening or shrinking deformation : This kind of deformation is relatively common, and the amount of deformation is generally 3-10mm; Distortion deformation: After twisting and deformation, the deformation amount may reach 10-30mm; Appearance shape does not meet the requirements: Some appearance shapes are more stric...

AI Technical Summary

Problems solved by technology

Ring castings have a large diameter span, especially the material is low carbon steel, and the material strength is between 300 and 500 MPa. A series of deformation problems are prone to occur during the defect welding process, mainly in the following aspects: size opening or shrinking deformation : This kind of deformation is relatively common, and the amount of deformation is generally 3-10mm; Distortion deformation: After twisting and deformation, the deformation amount may reach 10-30mm; Appearance shape does not meet the requirements: Some appearance shapes are more strict, and the dimensional tolerance requirements are high In terms of castings, deformation will inevitably lead to the appearance and shape of the castings not meeting customer requirements. If the above problems are not resolved, the subsequent welding repair costs and production cycle will be increased, and the repair cost caused by deformation may exceed the casting itself. The repair cost of the defect, if the repair measures are not taken properly, it may even lead to the scrapping of the casting. At present, there is no good method to prevent deformation during the welding process

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