CMT and laser cladding composite repair method for the inner hole of the flat head cover of the rolling mill spindle

Abstract

The invention discloses a CMT and laser cladding composite repair method for an inner hole of a flat head sleeve of a rolling mill spindle. The composite repair method comprises the following steps ofcutting the inner hole of the flat head sleeve to be repaired; removing a wear fatigue layer; cleaning the machined surface and removing impurities on the machined surface; using a CMT process to surfacing a transition layer on the machined surface; detecting the defects of a CMT welding layer, such as cracks; preparing alloy powders and cladding with a CW fiber laser, and coloring the surface ofa laser cladding layer to detect the detects, such as the cracks; and machining the laser cladding layer surface to obtain the flat head sleeve, specifically, the size, the tolerance and the surfacefinish of the flat head sleeve meet the requirements of a drawing. According to the CMT and laser cladding composite repair method for the inner hole of the flat head sleeve of the rolling mill spindle, a CMT welding process and a laser cladding process are organically combined, so that the purposes of low cost and agile repair are achieved; and the hardness and alloy compositions of the laser cladding layer can be quickly adjusted according to the change of working conditions, so that the service performance of a product is significantly improved and the service life of the product is significantly prolonged, and the service life is prolonged by more than two times

Description

technical field [0001] The invention relates to the technical field of metal surface engineering, in particular to a CMT and laser cladding composite repair method for the inner hole of a flat head cover of a rolling mill spindle. Background technique [0002] The cardan shaft of the main drive of the rolling mill is the most critical equipment of the rolling line. In this structure, the use and repair of the flat head cover is the core part of the equipment management of the rolling workshop. The flat headgear is made of 42CrMo medium carbon alloy steel, which has poor weldability. According to the actual amount of wear, the worn flat headgear is repaired by surfacing or plasma cladding process. Due to the required cladding layer thickness and surfacing area Large, large residual stress and large heat-affected zone are produced in the process of surfacing and plasma cladding. Although there is heat treatment stress relief in the subsequent process, the internal stress is on...

AI Technical Summary

Problems solved by technology

The flat headgear is made of 42CrMo medium carbon alloy steel, which has poor weldability. According to the actual amount of wear, the worn flat headgear is repaired by surfacing or plasma cladding process. Due to the required cladding layer thickness and surfacing area Large, large residual stress and large heat-affected zone are produced in the process of surfacing and plasma cladding. Although there is heat treatment stress relief in the subsequent process, the internal stress is only partially eliminated, and the remaining internal stress will be gradually eliminated during the use of the component. release, resulting in defects such as cracks in the repaired flat hood in a short period of time, which in turn accelerates the damage and failure of the repaired flat hood

Traditional repair processes such as surfacing and plasma cladding can no longer meet the needs of the harsh working conditions of flat hoods