Overlay Welding Repair Technology of Large 70cr3mo Backup Roll

Abstract

The invention discloses a large-thickness surfacing repairing layer for a large 70 Cr3Mo supporting roller and a repairing technology. The surfacing repairing layer is sequentially provided with two bottom layers, two transition layers and multiple work layers in the radial direction of the end face of the supporting roller from inside to outside. Study is conducted from the aspects of welding material selecting, surfacing technologies, surfacing process control and the like, a proper surfacing material and a rigid surfacing technology are determined so that the performance requirement and the surfacing quality of the surfacing layer can be ensured, and good technology equipment is designed and manufactured for ensuring implementation of technology measures. Finally, an abraded roller body is repaired to the original roller body size, the use performance is recovered, the service life exceeds the service life of the original roller body, and economical benefits are high. The large-thickness surfacing repairing layer can be used for the large supporting roller with the weight larger than 150 T, large-thickness surfacing layer with the thickness reaching 300 mm can be achieved, and the working layer hardness ranges from 50 HS to 60 HS; and the surfacing layer meets the ultrasonic flow detection JB / T4620 standard.

Description

technical field [0001] The invention relates to a large support roll, in particular to a surfacing repair process for a large 70Cr3Mo support roll. Background technique [0002] With the development of rolling mills in the direction of large-scale, high-speed and automation, the quality requirements for its back-up rolls are also getting higher and higher, and its market demand is also increasing. The large back-up roll is the main part of steel rolling, its quality is related to the quality and output of steel, and it is also the main consumption part of the rolling mill. With the wear and tear of each service cycle of the rolling mill, the roll diameter of the back-up roll is reduced to the limit size, or a small amount of working layer is lost due to partial peeling, and it cannot be used continuously. The direct scrapping of large back-up rolls will cause a huge waste of steel plant resources. For example, the back-up roll of Nanyang Hanye 3800 rolling mill has a weight...

AI Technical Summary

Problems solved by technology

The back-up roll was severely damaged and scrapped, and the technical difficulty of repair and the risk of failure were very high

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