The through shaft water-cooled roll is the most important equipment in the CSP (Compact Strip Production, compact strip steel production line) roller hearth heating furnace. It is mainly composed of a supporting roller shaft, a water-cooled steel pipe, a metal roller body, a heat-resistant metal roller ring, and a refractory heat insulating lining between the roller rings, etc. Its structure is complex and the production cost is high; The load-bearing of the heat-resistant metal roll ring is used to support the thin slab casting billet. Through the forward and reverse rotation and speed adjustment of the water-cooled roll, as well as the friction drive between the roll ring and the thin slab casting billet, the billet transportation in the furnace and the adjustment of the buffer time are completed. , to realize the heating process in the slab furnace.
The non-contact parts of the water-cooled roller and the slab are all wrapped with a refractory insulation layer to ensure the support strength and rigidity of the water-cooled roller under high temperature conditions, and to reduce the water cooling and heat loss of the furnace roller. Therefore, the water-cooled roller has the worst working environment, not only to withstand high temperature , Furnace gas erosion and corrosion, and also need to bear the influence of casting heavy pressure, impact and friction, resulting in serious mechanical damage to the refractory insulation lining and roll ring, high temperature creep, oxidation and nodulation of the roll ring metal, which not only affects the water cooling The comprehensive service life of the rollers, but also lead to indentations and water-cooled black marks on the surface of the slab, especially the water-cooled rollers of the roller hearth heating furnace with a furnace temperature greater than 1200°C, the damage is more serious. It can be seen that the water-cooled furnace rollers of the CSP roller hearth heating furnace have the characteristics of large number, poor working conditions, high water-cooling strength, complex structure and serious damage. Large key components are also the main components of the maintenance cost of the roller hearth furnace, and are also the key factors affecting the heating quality and surface quality of the slab. For this reason, scholars at home and abroad have carried out a series of research work from the perspective of extending the service life of the water-cooled roller and improving the heating quality and surface quality of the slab furnace. The patent discloses a new type of furnace roller for a roller hearth heating furnace, which includes a roller body, a water-cooling tube and a shaft head. The shaft heads are respectively fixed at both ends of the roller body, and the water-cooling tube is fixed inside the roller body. The roller ring is made of Cr35Ni55W9A12 material, which not only improves the wear resistance and high temperature oxidation resistance of the roller ring, but also only needs to replace the roller ring after the roller ring wears out. The maintenance cost of the water-cooled roller; in addition, refractory mud is installed between the roller rings, which not only reduces the surface temperature of the roller body, but also prolongs the service life of the water-cooled roller; but the structure of the water-cooled roller is the same as that of the water-cooled roller and the imported water-cooled roller. The ultra-high content of precious metal elements has led to a sharp rise in the price of roller rings, and there is no report on actual production and use. Qingdao Hexin Machinery Co., Ltd. found another Chinese patent with the patent application number of 200920186762.X and the invention titled "composite roller for roller hearth furnace", which discloses a furnace roller for roller hearth furnace, which consists of a steel shaft, a roller ring and a It is composed of refractory material, the roller ring is fixed on the steel shaft, and the refractory material is arranged on the steel shaft between the roller rings. The characteristic is that the roller ring is composed of a steel inner ring and a high temperature resistant outer ring. The inner ring keyway is arranged along the axial direction, the outer ring is annular, the inner wall is provided with the outer ring keyway along the axial direction, the inner ring keyway and the outer ring keyway are matched one by one, and are embedded together by keys. The outer ring is fixed on the inner ring, the inner ring is welded and fixed on the steel shaft, and then the refractory material is poured into the water-cooled roller. The advantage is that the surface of the first roll ring is smooth in high temperature resistance, which prevents the roll ring from sticking to steel and improves the surface quality of the billet. , Improve the heating quality of the billet; it has the characteristics of easy processing, less maintenance, and long service life. However, the mechanical impact resistance of brittle ceramic materials is insufficient. Under the strong impact during the slab conveying process, the mechanical damage of the ceramic outer ring will be caused, which will affect its actual use effect. There is no report on actual production and use. In addition, a European patent with International Application No. PCT/US94/03199, International Publication No. WO94/21978, and the invention titled "Roller for High-Temperature Roller Hearth Heating Furnace" discloses a variety of high-temperature roll-hearth heating furnaces. The furnace roll structure is made of heat-resistant alloy to make the roll ring. Through the design of various forms of furnace roll heat insulation lining structure, water cooling channel structure and roll ring structure, the heat insulation of the roll body and the cooling effect of the roll ring are strengthened, and the expansion The tolerance temperature range of the furnace roller is increased to meet the needs of high-temperature roller hearth heating furnaces. However, the structure of the water-cooling channel, the roller ring and the heat insulating lining of the furnace roll is complex and the manufacturing is difficult, which leads to a high comprehensive cost of the furnace roll. At the same time, the intensified cooling of the roller ring leads to a large loss of water cooling and heat of the furnace roller, which is not conducive to the energy saving of the roller hearth heating furnace. There have been reports in China that this technology has been tested on CSP roller hearth furnaces with a furnace temperature of less than 1200°C, but it was abandoned due to unsatisfactory service life and cost. In addition, Italian Dexing Company also has an example of using Co50 heat-resistant alloy roller rings to meet the requirements of CSP roller hearth heating furnaces with a furnace temperature higher than 1200°C, but Co50 heat-resistant alloy roller rings are very expensive and cannot be popularized and applied. . The document "Baogang Technology" published a technical paper (2004, 30 (2)), written by Feng Liyi, Zhou Jianping and Zhang Qian, titled "Development of Roller Rings for CSP Heating Furnace Furnaces" (2004, 30 (2)), which reported that heat-resistant metal for roller rings was The localization and application of materials, through the material analysis of the imported German LOI company's roll ring, in the case of ensuring the main components of C, Ni, Cr in the steel, and adjusting the microalloys Nb, Mo, Ti, Co, Al, The mass fraction of Si and the smelting method to reduce S and P in the steel have completed the development of the roll ring heat-resistant alloy, and achieved the same application effect as the imported roll ring without changing the structure of the roll ring, making the roll ring The cost is reduced by 2/3; but the maximum furnace temperature suitable for the roller ring is < 1200°C, which cannot meet the needs of higher furnace temperatures. To sum up, the relevant patents and technical research at home and abroad only consider the service life and maintenance costs of the furnace rolls, while the cost reduction and comprehensive performance of the furnace rolls for the high-temperature roller hearth heating furnace with a furnace temperature of more than 1200°C are considered. improvement requires further research.
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