Tungsten carbide roller is a tool material with high hardness and good wear resistance, which is widely used in cold rolling and hot rolling to produce steel bars and wire rods. With the advantages of wear resistance and high efficiency,it is necessary to master the characteristics of cemented carbide roller rings and the correct method of use to reduce the wear out and prolong its service life. Oston Carbide suggests that manufacturers should pay attention to the following tips when purchasing and using cemented carbide roller rings.
1. Proper grades of tungsten carbide rollers
Correctly select the cemented carbide grades used in each finishing stand to achieve the best match for each stand grade.
2. Carbide Roller assembly
Roller assembly must be carried out strictly according to the precision required by the design process. Proper cooperation between the roll ring, the frame roller shaft and the tapered shaft sleeve is required, and it cannot be too tight or loose.
3. Correct cooling for carbide rollers
The cooling of the roll ring during the rolling process is to reduce the hot corrosion of the rolling groove surface, thermal fatigue cracks and thermal stress on the roll ring during rolling, to prevent the roll ring from breaking ,delay the expansion of micro-cracks, and extend the ring roll life. Low cooling water pressure and water volume will accelerate the expansion of hot cracks and hot corrosion in the rolling groove, reduce the rolling groove production capacity, and even cause cracks to expand, causing roll ring rupture. The pressure of cooling water must be kept at 5-6 bar, and the water volume should be controlled at 18cm3 It is better to control the water volume of the last frame at about 24cm3/hour. The water spray should be radial and form an angle of 15-30 degrees with the direction of the roller ring. The water should not be scattered or mist, and it should be sprayed directly into the rolling groove.
4. Regrinding of carbide rollers
It is difficult to avoid micro-cracks in the rolling groove of the roll ring. When the micro-cracks in the rolling groove reach a certain depth (generally controlled at about 0.2mm), they must be removed and ground in time. This is to reduce and avoid the rolling groove to continue to expand and cause broken rolls. When the rolling groove is rebuilt, the micro-cracks must be completely ground away, otherwise the micro-cracks will bring a great risk of broken rolls in the next rolling; in order to ensure that the micro-cracks are completely worn out, a certain amount of grinding can be added. In the case of normal process rolling volume, the grinding is generally controlled to grind 0.4-0.6mm in the rear frame and 0.7-1.2mm in the front frame.
5. No overloading on the carbide rollers
Each finishing mill has correspondingly designed cemented carbide roll rings and assembly forms, which have different requirements for size and shape. The design load is generally 3-4 times the normal service load, but the tensile strength of cemented carbide is relatively low. Yes, a large load can destroy the fixing condition of the tapered bushing and the shaft to the roller ring, and produce a large local tensile stress to break the roller ring.
6. The handling and storage of the roller ring
Roll ring is a kind of brittle material, heavy and very easy to break. Therefore, the inspection, processing, warehousing, on-machine, off-machine, grinding and other processes of roller rings after unpacking should be put into a solid wooden box or a wooden box with a strong partition, one for each grid, for transportation and transfer .
7. The marking and management of tungsten carbide roller
Each roll ring supplied by Oston Carbide is marked with obvious dimension and grade, which must be carefully distinguished when grooving and matching rolls.For more information about cemented carbide roller rings, welcome to contact us.
