Welding and mending method for nodular cast iron workpiece

Abstract

The invention relates to the field of repair of nodular iron castings and discloses a welding and mending method for a nodular cast iron workpiece. The method comprises the following steps: S1, afterheating the vicinity of the integral workpiece or the defected part to a certain temperature, heating the defected part of the workpiece to a melting temperature; and S2, heating a nodular cast iron welding rod identical to or similar to the workpiece in material to a melted state, dropwise adding the molten nodular cast iron welding rod into the defected part, and keeping the temperatures of themolten nodular cast iron welding rod and the defected part which are combined being identical or similar. The invention aims to provide a nodular cast iron welding and mending method which is small inworkload and simple to operate, the repaired part is free of color difference and the strength is not deteriorated. No defect is found in the workpiece, on the surface of the workpiece and at the combined part of the workpiece through ultrasonic flaw detection and magnetic powder inspection on the welded and mended part and the periphery of the welded and mended part.

Description

technical field [0001] The invention relates to the field of repairing ductile iron castings, in particular to a welding repair method for ductile iron castings. Background technique [0002] Resin sand molding is one of the most commonly used, practical and extensive casting methods in the production of ductile iron castings, and can be applied to ductile iron castings of any shape and weight. In actual production, due to careless operation of the operator or insufficient strength of the sand mold, sand inclusion defects often appear, and the defect location is sometimes on the non-processed surface of the ductile iron casting, and sometimes on the processed surface of the ductile iron casting. When the sand inclusion defect appears on the important processing surface or stress position of the casting, it is basically scrapped; when the sand inclusion appears on the non-important processing surface or non-stress position or non-processing surface of the casting, the commonl...

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Problems solved by technology

[0003] However, there are the following disadvantages: the material of the electrode is different from that of ductile iron, the two do not match well, and the difference in hardness is large, especially after processing, the color difference between the two is relatively large

[0006] Of course, we have also tried to use ductile iron welding rods, and found that it still cannot be tightly integrated with the flaws of the workpiece

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