How is stainless steel made?

Manufacturing Process: How to make stainless steel

Once the raw materials have been collected, the rest of the stainless steel manufacturing process can begin. Here are the basic steps:

Melt the raw materials. Different stainless steel materials are placed in a furnace (usually an electric furnace for modern stainless steel manufacturing applications) and heated to their melting point. This process can take eight to 12 hours. Once the metal is melted, stainless steel manufacturing can proceed to the next step.

Remove excess carbon. The molten material is placed in a vacuum oxygen decarbonization (VOD) or argon-oxygen decarbonization (AOD) system to remove excess carbon. Depending on the amount of carbon removed, this process may result in standard or low-carbon variants of the alloy - for example, 304 and 304L stainless steel. This affects the tensile strength and hardness of the final product.

Tune or stir. To help fine-tune the quality of the final product, molten steel can be stirred to help distribute and/or remove specific stainless steel components from the mixture. This helps to ensure that the stainless Steel has a uniform quality and meets the specifications required by the end user, such as Marlin Steel.

Form metal. As stainless steel begins to cool, it undergoes various forming processes - starting with hot rolling, when the steel is still above its crystallization temperature. Hot rolling helps to shape steel into rough shapes and is often used to make metal billets or square billets. In order to produce metal billets or billets of precise size, stainless steel can be cold-rolled.

Heat treatment/annealing. In order to reduce internal stress and change the mechanical properties of stainless steel, it can be annealed (heated and cooled under controlled conditions). If annealed, the steel may need to be de-oxidized to avoid damage to the protective oxide layer.

Cutting and shaping. After the annealing process, the stainless steel undergoes various cutting and forming processes to create the ideal end product for the application. The specific operations used to cut stainless steel will vary depending on the size and shape of the billet/large flower and the end product required. For example, if thick metal plates are made, the steel can be mechanically cut using large metal shears. At the same time, CNC punches or laser cutters can be used to cut shapes from thinner metal sheets. Marlin Steel's manufacturing team often uses cutting lasers and CNC punches to create custom metal cuts from sheet metal plates.

Apply surface treatment. Stainless steel manufacturers may apply different surface treatments to stainless steel billets, billets, or wires before shipping them to other manufacturers. The specific finish applied will vary depending on the intended use of the steel - but one of the most common surface finishes is simply sanding the surface to remove impurities and make it smoother.