Submerged-arc surfacing flux-cored wire and technology for composite production and reproduction of continuous casting rollers

Abstract

The invention discloses a submerged-arc surfacing flux-cored wire and a technology for composite production and reproduction of continuous casting rollers. The deposited metals of the flux-cored wirecomprises components in percentage by weight as follows: 0.02%-0.3% of C, 0.8%-2.8% of Mn, 0.1%-1.0% of Si, 12.0%-15.0% of Cr, 0.3%-2.0% of Mo, 1.5%-5.0% of Ni, 0.01%-1.5% of rare-earth elements, 0-1.2% of V and Nb, 0-0.16% of N, less than 0.03% of S, less than 0.03% of P and the balance of Fe. The technology comprises steps as follows: (1) rollers are turned into the size before surfacing; (2) the rollers are detected before surfacing; (3) the surfacing technology is determined, and technological parameters are determined according to the surfacing technology; (4) single-layer surfacing forming is performed; (5) components, hardness and structures of different positions after surfacing are detected. The technology is good in technological property and has the high cost performance.

Description

technical field [0001] The invention relates to a submerged-arc surfacing flux-cored welding wire for composite (re)manufacturing continuous casting rolls and a technique, belonging to the field of welding technology. Background technique [0002] Continuous casting equipment has been widely used in major steel mills in my country. Continuous casting rolls are the main consumption parts in continuous casting equipment. Continuous casting rolls include three parts: crystallization section, sector section and horizontal section. Due to the dual role of cooling water, the working conditions are very harsh. Under the action of mechanical and thermal loads, the continuous casting rolls will have different degrees of network cracks, oxidation corrosion, wear damage and other damages on the roll surface during use, which will affect the continuous casting machine. Operating rate, product output and quality, unit roll consumption and rolled material cost. [0003] Surfacing welding c...

AI Technical Summary

Problems solved by technology

[0004] At present, the commonly used welding processes for continuous casting rolls are mostly submerged arc welding and open arc welding. When using single wire arc welding, it is only 5-6.5kg / h, and the thickness of one side of the surfacing layer is generally 2.0mm-2.5mm. Therefore, it is necessary The surfacing welding time is longer, and the production efficiency is not high; field practice shows that: the longer the surfacing welding time, the more surfacing layers, the more prone to surfacing defects

Especially in multi-layer welding, the upper layer will produce a certain thickness of heat-affected zone on the lower layer, which will have an adverse effect on the metal structure of the weld and seriously damage the service life of the continuous casting roll.

[0005] Overlay welding rolls, especially continuous casting rolls, are used to increase the height of the single-layer weld metal, so that the thickness of one layer of surfacing welding on one side can reach the current 2 to 5 layers (one layer of primer + two layers of cover or one layer of primer +Three-layer cover or other combination) the welding layer height, and the alloy composition and hardness and other properties can meet the technical requirements of (voestalpine, Danieli, Demark), on the one hand, it is limited by the difficult operation of the welding process , during the welding process, defects such as slag, overheating, and inclusions are prone to occur, and the welding process is not easy to implement; A large amount of ferrite is produced, which reduces the hardness; and when the alloy content of the surfacing alloy material is too low, due to the dilution rate, the alloy is diluted too much, and the composition (especially at 1.5mm of the base metal) is insufficient; both aspects lead to mechanical poor performance

Therefore, by increasing the height of the single-layer weld metal, the thickness of one layer of surfacing welding on one side can reach 2 to 5 layers of surfacing welding (one layer of primer + two layers of cover or one layer of primer + three layers of cover or The welding layer height, alloy composition and hardness can meet the technical requirements (voestalpine, Danieli, Demark) have not been reported

Images