Comparison of several repair methods of frame archway
1. Machining division
The online machining method is to remove the material by machining, remove the damaged layer leveling contact surface of the archway surface, and compensate for the enlarged size by increasing the thickness of the lining plate. This repair method is simple and convenient to operate, but it does not change the nature of the archway surface. After a period of use, the archway surface will be corroded and worn out and become invalid. Moreover, repeated mechanical processing will have a negative impact on the strength and stiffness of the archway. Considering the sensitivity of finishing mill to stiffness, there is not much machining margin, so this repair method can only be a temporary expedient.
2. Arc surfacing welding method
Arc surfacing method is to restore the machining process and remove the enlarged size of the material, so as to change the properties of the archway surface and improve the service life of the archway by welding a layer of anti-corrosion and wear-resisting material on the spot. Large area arc surfacing welding on rigid structure such as arch may cause deformation of arch structure. If there is a distortion or instability in the structure that is fatal and cannot be corrected, that is not allowed to happen in the factory. Therefore, this repair method will bring greater risks and is generally not adopted.
3. Laser surface cladding
Laser surface cladding has the characteristics of high energy density, compact cladding quality, high bonding strength, low dilution rate of cladding layer structure and small heat affected area. The laser surface cladding is non-contact machining and the input heat is controllable. The standard laser repair method can solve the welding residual stress and cracking tendency caused by other welding methods. So we can adopt the method of machining to remove corrosion and wear of fatigue layer on the surface of the memorial arch, then select corrosion resistance and abrasion resistance are better than that of base material powder, adopt the method of laser cladding to repair of memorial arch, it avoids many times to remove the monument material to the decline in the strength of the defect, and avoid the welding deformation problems caused by stress concentration caused by the memorial arch was raised and the corrosion resistance and abrasion resistance.
Analysis on the main reasons of mill archway wear: 1. Metal fatigue wear; 2. 2. Corrosion of cooling water; 3. During the running of the mill, bolts fastening the lining plate become loose and bolt elongation occurs. Aiming at the characteristics of large and difficult to move mill archway, zhongke yuchen specially developed a mobile robot laser remanufacturing equipment.