What are the main performance requirements of the rolls in detail?
Roll is the main working part and tool to produce continuous plastic deformation of metal on the rolling mill. Its main performance requirements are.
Heat crack resistance
Usually the main requirements for rough rolls are strength and resistance to thermal cracking; the rolls of small 20 mills weigh only about 100 grams, while the weight of the support rolls of wide and thick plate mills has exceeded 200 tons. When selecting products, the main material for safe load-bearing is first selected according to the basic strength requirements of the mill.
Hardness
While the finishing roll speed is higher, rolling products to have a specific surface quality, for it to hardness, wear resistance, etc. as the main requirements. Then consider the wear resistance due to the use of the product. Because the wear mechanism of the product is 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 yet a comprehensive assessment of the product wear resistance of a unified index. Since the hardness is easy to measure and can reflect the wear resistance under specific conditions, the radial hardness curve is generally used to approximate the wear resistance index of rolls.
Impact resistance
In addition, there are some specific requirements for the product, such as a large amount of pressure down, the product is required to have a strong bite into the ability, more resistant to impact;
Smoothness
When rolling thin specification products, the requirements for product rigidity, uniformity of tissue properties, processing accuracy and surface finish are more stringent;
Cutting performance
When rolling complex sections of sections, the cutting performance of the working layer of the roll body is also considered.
When selecting the product, some of its performance requirements are often opposed to each other, and the product acquisition and maintenance costs are expensive, so the technical and economic pros and cons should be weighed to decide whether to use cast or forged, alloy or non-alloy, single material or composite material.