The main properties of tungsten carbide to be considered in selecting tungsten carbide rolls are as follows:
Resistance to thermal cracking
Usually for rough rolls to strength, resistance to thermal cracking as the main requirements; small 20-roll mill working rolls weigh only about 100 grams, while the weight of the support rolls for wide plate mills has exceeded 200 tons. Selection of rolls first according to the basic strength requirements of the mill on the rolls, selected to safely carry the main material (various levels of cast iron, cast steel or forged steel, etc.).
Hardness
And finishing roll speed is higher, rolling the final product to have a certain surface quality, to it to hardness, wear resistance, etc. as the main requirements. Then consider the rolls should be used when the wear resistance. Because the wear mechanism of the roll is very complex, including the mechanical stress effect, the thermal effect of rolling, cooling, the chemical effect of the lubricating medium and other effects, there is not a comprehensive assessment of the roll wear resistance of a unified index. Since the hardness is easy to measure and can reflect the wear resistance under certain conditions, the radial hardness curve is generally used to approximate the wear resistance index of rolls.
Impact resistance
In addition, there are some special requirements for the rolls, such as a large amount of pressure, the rolls are required to have a strong bite into the ability, more resistant to impact;
Smoothness
When rolling thin specification products, the rigidity, uniformity of tissue properties, processing accuracy and surface finish of the rolls are more stringent requirements;
Cutting performance
When rolling complex sections of sections, also consider the cutting performance of the working layer of the roll body.
When selecting rolls, some performance requirements for rolls are often opposed to each other, roll purchase and maintenance costs are very expensive, so the technical and economic advantages and disadvantages should be fully weighed to decide whether to use cast or forged, alloy or non-alloy, single material or composite materials.
Post time: May-23-2023
