Application case overview
Although the transmission shaft (flat head sleeve) has good hardness, it has poor impact resistance, cannot be restored after deformation, and has poor fatigue resistance, so it is easy to cause fatigue wear of the shaft head. After most shafts are worn, it is easy to cause the machine to increase the beating amplitude or make noise. Increase the size and seriously cause the machine to shut down.
Flat hood background
The main drive cardan shaft is widely used in the field of metallurgical rolling. As one of the most critical components connecting the roll and the main drive shaft, the flat head sleeve is used to transmit the interaction and torque between the main drive cardan shaft and the roll.
Repair request
Comprehensively clean the entire flat hood; conduct non-destructive testing, hardness testing, dimensional inspection, etc. to remove the fatigue layer of the flat hood; determine the specific parameters of laser cladding and perform laser cladding on the repair part of the flat hood; flat groove hardness HRC45-50; keyway wear Repair (laser cladding or surfacing welding, no deformation required); replace worn keys and keyway connecting bolts, bolts are grade 12.9; cracking and deformation cannot occur due to surfacing repair.
Figure 3.42 Disassembly and cleaning of flat hood before repair
Construction Equipment
4KW fiber laser equipment, with 10mm linear spot module and nozzle; Vickers hardness tester JMHVS-1000ZDP; MP-2A metallographic sample polishing machine; DK7725 EDM CNC wire cutting machine; GX40 metallographic microscope; composition detector; horizontal type turntable; large gantry milling machine.
Material
According to the technical requirements, our commonly used iron-based powder Fe-S08 is selected for cladding. The hardness of the cladding layer can reach 47-50HRC; the powder particle size range is 53-150um.
Figure 3.43 Repair technical solution
The process parameters determined in the cladding process experimental stage were used to carry out laser cladding repair on the inner wall of the flat hood; a large area of cladding was carried out on the inner wall of the flat hood. The cladding layer was continuous and uniform, with a single-layer thickness of about 1mm and multi-layer cladding. By conducting a PT inspection on the cladding layer, it can be seen that there are no cracks in the cladding layer and the molding effect is good.
Figure 3.44 The inner hole is fully cladded with a thickness of 1mm
Figure 3.45 Colored flaw detection to detect cracks and pores
Inner hole machining
Painting assembly
Use the process parameters determined in the experimental stage of the cladding process to carry out laser cladding repair on the inner wall of the flat headgear;
A large area of cladding is carried out on the inner wall of the flat hood. The cladding layer is continuous and uniform. The single-layer thickness of the cladding layer is about 1mm, and multi-layer cladding is required.
By conducting a PT inspection on the cladding layer, it can be seen that there are no cracks in the cladding layer and the molding effect is good.
Colored flaw detection to detect cracks and pores