Tungsten carbide roll rings are often used in high-wire rolling mill rolling, and cracks are often found in the holes and grooves of the roll rings in the production and rolling, which can easily produce cracked rolls, which directly affects the quality and progress of roll ring processing, and affects the quality and output of finished products to varying degrees. Therefore, it is important to analyze the causes of cracks in cemented carbide roller rings and take effective measures to control and prevent them.
Tungsten carbide roller rings have the characteristics of good wear resistance, high temperature red hardness, heat fatigue resistance and thermal conductivity, as well as high strength. It is a key component in the production of high-speed wire rod rolling. Tungsten carbide roll rings are mainly used in the pre-finishing mill, finishing mill and sizing unit of high-speed wire rod mill, which plays a role in reducing the area of rolling parts and improving the material performance of rolling parts. Tungsten carbide roller ring is a tool material with high strength and high wear resistance composed of hard tungsten carbide particles and metal binder, and sometimes some nickel, chromium, etc. are added to the binder phase to obtain the corresponding properties.
In the rolling process, the hot-rolled parts are in contact with the surface of the rolling groove, so that the surface temperature of the roller ring rises, and this part of the metal wants to produce expansion, and the metal temperature of the deep layer of the roller ring is small due to the temperature rise, and the compressive stress will be produced on the surface metal of the roller ring;
If the roller is not replaced in time, the microcracks will extend and make the microcracks wider and deeper, or cracks will appear, and in severe cases, the roller rings will burst to rupture.
Tungsten carbide roll rings form hot cracks in hot rolling, and the propagation of hot cracks depends not only on the cooling effect, but also on the material being rolled. Rolling and corrosion can cause surface defects in the hole groove, which can cause premature fracture of the roll ring, and hot cracking can also accelerate the defect on the roll ring surface.
So how to take effective control measures? To control the propagation of hot cracks, it is necessary to process and repair the tungsten carbide roller ring before it cracks, and also to control the amount of steel in a single groove.
The microcracks on the roller ring should be repaired in time and thoroughly grinded. In addition, a reasonable rolling volume is also the basis for determining the grinding amount of the roll ring. The microcracks that occur during the groove rolling process of the roll ring will expand and deepen over time. In short, hot cracks of cemented carbide rolls are inevitable, but they can be re-sharpened in a timely manner; according to the use of different units to roll different specifications and different materials of roller rings, determine the amount of steel passing through a single groove; the amount of processing must be specified for the roller rings; establish a strict processing and inspection and acceptance system to control the occurrence of cracks and repair them in time.
Post time: May-14-2024