The processing of rolls is mostly turning, and a few are milling. This article mainly introduces the selection of turning tools for processing rolls. We all know that the roll is an important part of the rolling mill, and it is the steel that turns the rolled material into various structural methods, such as steel plate, steel wire, U-shaped steel, T-shaped steel and so on.
The cost of rolls is about 5%-15% of the production cost of steel rolling, which is directly related to the production power, product quality and production cost of steel production enterprises. Therefore, more and more high-hardness rolls appear, such as high-nickel-chromium cast iron rolls, Chilled cast iron rolls, nickel hard cast iron rolls, high speed steel rolls, high boron steel rolls, carbide rolls/roll rings, etc. How to choose turning tools for such a high hardness roll?
Problems often encountered when processing rolls
1. High hardness. The hardness of the rolls after casting is generally above HSD75. Especially now, more and more cemented carbide rolls/roll rings are on the market, and the hardness is extremely high, which cannot be processed by traditional tools.
2. Low power. Because of the high hardness of the heat-treated rolls, grinding is generally used, or traditional tools may be used to gradually "gnaw", especially for large rolls with large margins and extremely low processing power.
3. The tool is not wear-resistant. As-cast rolls not only have high hardness, but also often have casting defects such as sand inclusion and pores, which will cause rapid tool wear and low life, and frequent tool changes will affect normal processing.
Selection of processing roll turning tools
For high hardness rolls, the current turning tool raw materials areCBN tools andPCD tools , the whole process of CBN tools are cubic boron nitride tools , PCD tools areDiamond tools . For different raw materials, choose different super-hard knives .
The main components of CBN tools are CBN particles (cubic boron nitride) and special ceramics and metal binders, which have high hardness at room temperature and high temperature. Tool raw materials that have less chemical reaction with the material to be cut. Mainly for ferrous materials, such as high nickel-chromium cast iron rolls, chilled cast iron rolls, nickel-hard cast iron rolls, high-speed steel rolls, high boron steel rolls, etc., cutting with large allowances, even if there are serious sand inclusions / pores on the surface, there is no any impact. Among them, the BN-K1 raw material CBN turning tool is used for processing high-hardness cast iron rolls, the BN-S20 raw material CBN turning tool is used for processing high-hardness cast steel rolls, and the BN-S10 raw material CBN turning tool is specially designed for high-speed steel rolls.
PCD Cutting tools are mainly aimed at cemented carbide rolls/roll rings. The hardness of cemented carbide rolls is too high, which has exceeded the acceptable hardness range of CBN tools, so higher PCD Cutting tools can only be used for turning. Among them, CDW010 raw material is a general raw material with balanced power and life. If there are special requirements for a certain item, such as smoothness or wear resistance, CDW302, CDW005 and other raw materials can be used to "prescribe the right medicine".
