Differences between Cold Rolling and Hot Rolling of WC Roll Rings
Rolling is an important manufacturing process emplyed in many industries, such as in the manufacture of rings for use in engineering applications. Tungsten carbide (WC) is a common material for roll rings used for engineering applications due to its excellent wear and abrasion resistance. However, in order to properly make use of WC’s properties, the proper rolling process must be employed during the manufacturing stage. To that end, cold rolling and hot rolling processes are available for forming WC roll rings, each with its own set of requirements. This article will discuss the major differences between cold and hot rolling of WC roll rings.
The cold rolling process utilizes a hardened tool to deform the workpiece, forming the desired shape without any significant rise in temperature of the workpiece. This process is typically used when a precise shape is required, such as in the case of rings with intricate designs. Furthermore, this process can result in workpieces with superior surface smoothness, as it has less tendency to cause tears or other imperfections in the material. On the downside, as cold rolling deformations are surface-only, the resulting roll rings may have poor internal strength, as well as have a reduced bulk hardness due to the lack of martensitic transformation when the material is deformed.
On the other hand, hot rolling process utilizes a heated tool to deform the workpiece, which results in the workpiece undergoing an austenitic transformation and generating significant amounts of heat. This process is most often employed when forming large, complex shapes in the workpiece, such as in the case of large-diameter WC roll rings. In addition, since the workpiece is heated, this process can increase the strength of the material due to the formation of martensite, as well as result in a higher bulk hardness. However, the excess heat generated and softening of the workpiece can result in tears and surface roughness in the final product.
In conclusion, the cold rolling and hot rolling processes are both viable methods for forming WC roll rings. Each process has its own advantages and disadvantages that can be used to determine the best choice for a given application. Generally speaking, cold rolling is best used when precise shapes with superior surface smoothness are desired. Hot rolling, on the other hand, is often employed when forming large, complex shapes with higher strength internal structures.
