In the past, stainless steel alloys were categorized into ferritic and martensitic types. Ferritic alloys contain 10-12% chromium and are non-hardenable. Martensitic alloys have higher chromium and carbon content than ferritic stainless steels, and also include manganese and silicon, which allow the alloy to be hardened through heat treatment processes. Currently, ferritic and martensitic stainless steel alloys are not widely used in industrial environments but are found in household items such as kitchen or garden tools.

As the applications of stainless steel processing continue to expand, stainless steel is frequently used in scenarios where high mechanical strength and corrosion resistance are required. To enhance the strength of stainless steel, metallurgists add nickel, transforming the iron/chromium alloy into an iron/chromium/nickel alloy. These materials are known as austenitic stainless steel and are now widely employed in industrial settings that demand high strength, corrosion resistance, and heat resistance. The alloy is commonly used in petrochemical processing, the food industry where corrosion prevention is necessary to meet hygiene standards, and general machinery operated under harsh environmental conditions.

Additionally, enhancing the performance of stainless steel will inevitably significantly increase the difficulty of its processing. The corrosion resistance of ferritic and martensitic stainless steel is essentially a chemical property, so these types of stainless steel are not harder to process than ordinary steel. However, adding nickel and other elements to austenitic stainless steel improves hardness, strength, deformation resistance, and thermal properties, leading to reduced processability.