Online repair method for window rolling stress surfaces of rack archways of hot continuous rolling units

Abstract

The invention discloses an online repair method for window rolling stress surfaces of rack archways of hot continuous rolling units, and the method comprises the following steps of: building a repair construction platform based on the upper plane of an oil cylinder at the bottom of a rack archway; moving a movable milling and boring machine tool to the inside of the rack archway, and arranging the movable milling and boring machine tool on the construction platform; adjusting the levelness of the machine tool, and respectively milling each liner plate stress surface of the window of the rack archway; arranging a laser cladding machine on the construction platform, connecting accessories, and adjusting cladding parameters; by using cobalt-based alloy powder, respectively carrying out laser cladding on each liner plate stress surface subjected to milling and at the window of the rack archway through the laser cladding machine; and carrying out grinding and polishing treatment on each liner plate stress surface subjected to laser cladding by using a grinding wheel. According to the method disclosed by the invention, the defects existing in the traditional repair method are overcome, the anticorrosive and wear-resisting performances of the window rolling stress surfaces of the rack archways are effectively improved, the material properties of the liner plate surfaces of the rack archways are completely changed, the service life of the rack archway is prolonged, the repair efficiency is improved, and the normal operation of the hot continuous rolling units and the quality of the billet rolling products are ensured.

Description

technical field [0001] The invention relates to an on-line repair method for the rolling force-bearing surface of the frame archway of a hot continuous rolling mill. Background technique [0002] The rack arch of the hot continuous rolling mill is an important part of the hot continuous rolling mill. The rack is used to install the rolls and adjustment devices for rolling billets. The rack bears the rolling force and has sufficient strength and rigidity. During the billet rolling process, the rolling conditions are very harsh. The rolls pass through the bearing housings to generate a greater impact on the frame archway, and the rolling cooling water is quickly atomized when it encounters the red-hot billet, and sprays around with the iron oxide powder falling off the surface of the billet; affected by the rolling impact, cooling The influence of water corrosion and oxidized dust and abrasive particles caused corrosion and wear to varying degrees on the rolling force surface...

AI Technical Summary

Problems solved by technology

This repair method is simple to operate, but it does not change the nature of the rolling force-bearing surface of the window of the archway. After a period of use, the surface of the force-bearing surface of the window liner of the archway will be corroded and worn and become invalid. The strength and stiffness are adversely affected. Considering the sensitivity of the rolling mill to the stiffness of the stand, there is not much allowance for machining. This repair method can only be a stopgap measure

At the same time, arc surfacing also has certain defects. The structural stress and residual stress generated during the surfacing process are relatively large, exceeding the yield strength of the main body material of the lining plate. If the surfacing welding is carried out on the lining plate of the archway window with a large area, it is likely to cause The instability and deformation of the frame archway structure can no longer be corrected, and the arc surfacing welding speed is slow and the efficiency is low. The surfacing layer needs to be machined, which affects the repair efficiency

Images