Steel Rolling employs a deceptively simple principle. Metal Stock is passed through one or more pairs of rolls, which reduces its thickness and produces a flat, even sized sheet of material. As a process this has a long history with crude Rolling Mills found back as early as 600 BC, and in Europe the invention may be attributed to Leonardo Da Vinci. Today there are many types of rolling processes, including ring rolling, roll bending, roll forming, profile rolling, and controlled rolling.
Needless to say a key component in all of these processes are the rolls themselves. Any Roll whether employed in hot or cold rolling techniques undergoes a high level of wear that affects it’s part life and must also contend with an often hot oxidising environment, corrosion and fatigue.
In order to combat this, Steel Mill Rollers have been manufactured out of Carbon Steels, Aluminium, Stainless Steels and other non-ferrous metals. Although these metals may be suitable, they often don’t have the desired part life and the cost of replacement can be quite steep. Two ways that manufacturers have sought to address this are through the use of higher grade alloys that utilise chromium and tungsten and through electro-plating techniques such as Hard Chrome Plating.
Hard Chrome Plating does produce a smooth surface, but is under threat from European restrictions on Hexavalent Chromium due to the carcinogenic nature of the process. Using higher grade alloys may extend the part life, but normally has cost implications especially at the moment where materials such as Tungsten are listed as Conflict Minerals.
Rather than sourcing this material, a more viable option might be HVOF. HVOF is a process which takes powdered materials, heats them up and fires them out at extreme velocities in order to effectively ‘spray’ them onto the material. Rather than using Tungsten Carbon Alloys as a base material, HVOF would allow you to use a cheaper grade of metal, coat it with Tungsten Carbon and in this way protect the part at a lower cost, whilst increasing the part life of your roller. HVOF can be used to coat a wide variety of cermet materials suitable for different applications meaning you can effectively tailor the solution to suit your needs.
If you’re working for a way to extend the part life of Steel Mill Rollers or anything that is likely to encounter high levels of wear, corrosion or temperature than HVOF might be exactly the process you are interested in. Get in touch with B&B Coating to see how we can help you with your application.