Motor rotor web crack welding repair method

Abstract

The invention discloses a motor rotor web crack welding repair method and solves the problems that a saw-toothed or crescent electrode is originally used to increase bath width and weld width, thermal stress is large and cracking occurs easily. A linear electrode manipulation method is adopted, a low-current small width welding method is adopted, arc ending is slow, a segment is re-welded to fill an end arc pit, the weld shape is changed, and cracking is avoided accordingly. A welding electrode A507 with higher tensile strength is used, a series of welding processes is taken, and the tensile strength of special equipment and special welds is met. The use of symmetric welding prevents excess welding stress effectively.

Description

technical field [0001] The invention relates to a method for repairing a motor rotor web crack by welding. Background technique [0002] Penetrating cracks often appear on the rotor web of the coal mill motor, and the main reasons for the cracks are as follows: [0003] (1) Influence of engineering material The engineering material is low-carbon alloy steel, and the high carbon content and the increase of impurities such as phosphorus and sulfur are one of the factors that cause cracks; [0004] (2) The diameter of the rotor web is too large, the thickness is too large, and after long-term operation, intricate superimposed stresses have accumulated inside; [0005] (3) During the welding process, welding deformation occurs in the weld area, and the workpiece is not easy to generate internal stress due to its high rigidity, which makes some low-melting point impurities easy to concentrate in the center of the weld. When shrinking, the weld seam and the vicinity of the heat-...

AI Technical Summary

Problems solved by technology

[0004] (2) The diameter of the rotor web is too large, the thickness is too large, and after long-term operation, intricate superimposed stresses have accumulated inside;

The existing welding repair methods use zigzag or crescent-shaped strips to increase the width of the molten pool, the weld seam is wide, the thermal stress is large, and cracks are prone to occur, but none of the above requirements can be fully guaranteed