Raw materials

Stainless Band understands stainless steel and is very selective in choosing the right grades for its customers. To many people not involved in the industry, one stainless steel is much like another, but understanding the eventual use guarantees the right result. There are a very large number of standard stainless steel grades, as well as special grades produced by the various stainless steel producers. Choosing the right one is paramount to success.

Stainless steel is an alloy made up of a number of elements, the principal one being iron (Fe). Carbon is also required, which turns the iron into steel. But the key element to turn this into stainless steel is chromium, which gives the material its corrosion resistant properties – to be categorised as stainless steel a minimum of 10.5% chromium is required. Additional alloying elements can be added, such as nickel, molybdenum, manganese and nitrogen to achieve the final desired properties, or in some instances to reduce alloy costs.

Stainless steel is usually produced in an electric arc furnace, into which scrap, and alloying elements such as ferrochrome and ferronickel, are charged, and then melted. This can take around an hour to an hour and a half depending on a number of factors such as furnace and transformer size. The molten stainless steel is then usually transferred to an AOD (argon oxygen decarburisation) converter to reduce the carbon content to the specified level for the particular grade, and where additional fine-tuning of the chemical composition can be carried out. The molten metal is then ready (perhaps with additional fine-tuning in a ladle furnace) to be transferred to a continuous casting machine for casting into slabs, blooms or billets.

After casting, blooms and billets can then be rolled into bars and sections (that is long products). Slabs are used for the production of flat products, and are initially hot rolled to produce hot rolled coil. After annealing and pickling, this material can be used directly for certain applications, but the surface finish (most commonly 1D), is non-reflective and is of a quality that makes it unsuitable for many demanding applications, including, for example, decorative applications where aesthetic properties are paramount.

Hot rolled coil usually, however, undergoes a number of further processing steps. After annealing and pickling, it is cold rolled, with a subsequent annealing and pickling process, to produce cold rolled coils, more often than not with a surface finish known as 2B, a greyish and moderately reflective mill finish. Cold rolled coil can also be “bright annealed” on a BA line creating a bright, reflective mill finish. Material with a 2B or BA mill finish can be used directly in many applications, but 2B material especially is often just the starting point for finishing operations, usually carried out at a service centre.

Finishing is the final process step, and can include grinding, brushing, polishing, or mirror polishing. It is how this is done – grit size chosen etc – that imparts the final surface finish to perfectly match the requirements of the particular application, both with regard to surface appearance and the corrosion resistance of the material in a particular environment.

Having knowledge of these processes allows Stainless Band to select the best suppliers for its customers’ needs. The material is then purchased and stored in its 16,600 sq. ft. manufacturing facility ready for immediate processing, finishing and supply to customers. Currently, Stainless Band holds over 1,000 tonnes of material in stock in various grades and thicknesses, which allows for fast processing and a fast turnaround on its customers’ orders. With its in-house facilities, Stainless Band can guarantee the perfect match between the material it supplies and its customers’ requirements – the correct grade, the perfect surface finish, slit to the precise strip width required, with the specified edge condition, and on-time.

Understanding the industry, and investing in raw materials and storage facilities, enables Stainless Band to be a leading supplier for manufacturers demanding a fast, efficient and high quality supply chain for stainless steel strip, band, coil and sheet.