Tungsten carbide roll ring is a tool material with high hardness and high wear resistance composed of tungsten carbide and bond metal. Tungsten carbide roll ring should be used to give full play to its high wear resistance, long life and high wear resistance in high-speed wire rolling. For the advantage of efficiency, when purchasing and using a tungsten carbide roll ring, pay attention to the following matters:
1. Brand Selection
A comprehensive understanding of the performance of each grade of cemented carbide is the basis for the correct selection of the grades of cemented carbide roll rings used in each frame, and the need for the best matching of each frame grade.
2. Roll ring Installation
The inlay and assembly of the tungsten carbide roll ring be carried out strictly according to the accuracy required by the design process. The roll ring shall be properly matched with the roll shaft and cone sleeve of the stand, and it shall not be too tight or loose. When the roll ring is too tight, it will be in a large state, and the slightly large rolling force fluctuation will cause the roll ring to break. When the roll ring is too loose, it will cause relative sliding between the roll ring and the shaft and cone sleeve, and scratch the cone sleeve and roll shaft, which will cause the roll ring to break, It is necessary to check whether the roll ring meets the requirements before the operation, and the assembly surface of the roll ring, cone sleeve and shaft should be carefully scrubbed. It is strictly forbidden to knock the roll ring with a hammer or other hard objects when operating the machine, and it is strictly forbidden to collide with each other during transportation and installation, so as to prevent damage to the roll ring.
3. Cooling and Cooling Water Quality
Cooling is to reduce the effect of hot corrosion, thermal fatigue and thermal stress on the tungsten carbide roll ring during rolling, prevent the roll ring from cracking, delay the crack propagation and prolong the rolling groove life. It is very important for the effect of cemented carbide roll ring to play. The reference specifications for cooling are as follows: the temperature of cooling water is lower than 25 ℃, the pressure of cooling water is (5-6) bar, the water volume is (24-30) m3 / h, and the spraying water should be (5-6) Radial direction, at an angle of (15-30) degrees to the rotation direction of the roller ring. The width of the water column is twice as wide as that of the rolling groove, so it should be directly sprayed into the rolling groove, and water can not be scattered or foggy.
Water quality requirements:
YGH series should be used in neutral or weak alkaline water with pH ≥ 7.2
Ygr series can be used for slightly acidic water with pH ≥ 7.2 or pH ≤ 7.2
Solid particle content in water < 15 mg / L
4. Reasonable Rolling Quantity
It is inevitable that micro-cracks appear in the groove during rolling. When the groove reaches a certain depth (generally controlled at 0.2mm), it needs to be ground. Excessive rolling will lead to rapid expansion of microcrack depth and increase the risk of roll breakage, which should be prevented. The recommended range of normal rolling capacity is as follows: pre-finishing mill stand: (3500-4000) tons
Finishing mill 1-2 stands: (1800-2500) tons
Finishing mill 3-4 stands: (1800-2500) tons
Finishing mill 5-6 stands: (1500-2000) tons
Finishing mill 7-8 stands: (1500-2000) tons
9-10 finishing stands: (600-1200) tons
Reducing and sizing frame: (600-1200) tons
5. Grinding of Rolling Groov
Microcracks will appear in the groove rolling cutter for a certain period of time. When the micro-cracks extend to 0.2mm, they should be ground. It is necessary to grind the micro-cracks thoroughly, otherwise, the micro-cracks that are not completely ground will make the micro-cracks expand more quickly in the next rolling, and the roll ring will be broken. It is suggested that the grinding amount should be controlled as follows:
Finishing mill (9-10) stand roll ring (0.4-0.6) mm
Finishing mill (1-8) stand roll ring (0.7-1.2) mm
Tungsten carbide roll ring of pre-finishing mill (1.2-2.0) mm
