A method for repairing the hydraulic cylinder of the bending roll of a thick plate rolling mill

Abstract

The invention discloses a method for repairing a cylinder barrel of a bending roller hydraulic cylinder of a heavy plate mill. According to the method, first, a hole is bored in the cylinder barrel of the bending roller hydraulic cylinder; then, a steel bushing matched with the cylinder barrel in size after the hole is bored is manufactured; then, the cylinder barrel is heated as a whole, wherein the heating temperature is controlled to range from 110 DEG C to 120 DEG C; the steel bushing is cooled through dry ice, wherein the temperature is controlled to range from minus 50 DEG C to minus 60 DEG C; next, the steel bushing is sleeved with an O-shaped ring and installed in the cylinder barrel; at last, the cylinder barrel is cooled in the air to reach a room temperature, the outer end of the steel bushing is welded to the cylinder barrel in an argon arc welding mode, and the welding surface is polished. By the adoption of the method for repairing the cylinder barrel of the bending roller hydraulic cylinder of the heavy plate mill, the original drawing size of the cylinder barrel is restored, and the cylinder barrel is more resistant to corrosion and wear; besides, even if the cylinder barrel is worn in the future, the cylinder barrel can be used again as long as the steel bushing is replaced, as a result, the service life of the bending roller hydraulic cylinder used in the heavy plate mill is greatly prolonged, and repair expenses are reduced.

Description

technical field [0001] The invention relates to hydraulic cylinder repair technology, more specifically, relates to a method for repairing the cylinder barrel of the bending roll hydraulic cylinder of a thick plate rolling mill. Background technique [0002] During the rolling process of the steel plate, the shape of the roll gap changes due to factors such as the bending elastic deformation of the roll, the thermal expansion of the roll, the wear of the roll, and the elastic flattening of the roll, so that the rolled steel plate cannot meet the requirements. With the development of technology, a CVC (continuously adjustable crown) roll has appeared, which can move along the roll axis, so that the crown of the steel plate has been greatly improved. However, the CVC shifting system can only be adjusted without rolling steel. It is a preset setting and a static adjustment. Due to the unstable influence of many factors in the actual rolling process, it cannot be guaranteed to b...

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Problems solved by technology

[0003] During the actual use of the 5m thick plate bending roll of the thick plate manufacturer, the inner wall of the bending cylinder is severely worn and roughened, and it cannot be used any more. Generally, when the cylinder of the hydraulic cylinder is worn and the piston is available, it can only be remade One cylinder can be repaired, but the cylinder of the bending cylinder is composed of four cylinders to form a boss. If it is scrapped, it will cause millions of waste

Another method is to use the inner hole butt welding method to repair, but the cylinder of the bending cylinder is a blind hole, and the hole diameter is small and deep, so the inner hole butt welding cannot be implemented. In order to reduce the repair cost, a suitable method must be selected for repair

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