Stainless Steel or Inox Steel is an iron alloy containing an array of elements such as silicon, manganese, nickel, and the primary element Chromium. Chromium accounts for a minimum of 10.5% of the materials in Stainless Steel and is the element responsible for corrosive resistance – a higher amount of chromium would result in a higher level of resistance. Stainless Steel is well recognised as a material that is resistant to rust, stains, and corrosion. Pots and pans, cutlery, sinks, BBQs, fridges etc can all be made from Stainless Steel because it is durable and convenient to wash. Industrial Nuts, bolts and wire can also be stainless steel. So how is stainless steel made?
Step 1: MELTING
All materials involved in making stainless steel are put into an electric furnace where they are left for 8-12 hours, until they become molten.
Step 2: CASTING
The molten steel is moulded into a semi finished form – typically slabs, rods, tubes or billets.
Step 3: FORMING
The steel is now hot rolled through a rolling machine. Slabs from step 2 are formed into sheets and stripe. Billets are formed into bars and wires.
Step 4: ANNEALING
The steel is now heated and cooled repeatedly in a controlled environment. This is designed to release stress from the steel, allowing the material to soften and be useful for a wide variety of projects. It is important to keep the heating and cooling controlled because any alterations to the pressure or conditions can create a damaged product.
Step 5: DESCALING
During the annealing process the steel can develop ‘scales’ and this therefore needs to be removed. This is done through a method known as ‘Pickling’ where the steel is bathed in nitric-hydrofluoric acid.
Step 6: CUTTING
The steel, now semi-finished, heat treated and descaled is ready to be cut. The steel can be cut into any shapes with guillotine knives and high speed blades.
Step 7: FINISHING
The last step is making sure the stainless steel looks nice. This can involve buffing and grinding to ensure the steel is shiny and aesthetically appealing,.