What Is SAE 304 Stainless Steel?
SAE 304 stainless steel, an austenitic stainless steel, is primarily composed of iron, chromium, and nickel. This type of stainless steel, containing 18% chromium and 8% nickel, is the most commonly used due to its excellent rust and corrosion resistance. It’s malleable, weldable, and boasts significant heat resistance, enduring temperatures up to about 1652°F (900°C), making it adaptable for both low and high-temperature processing.
Uses of SAE 304 Stainless Steel
304 stainless steel’s diverse applications span household items, construction, industrial products, and electronic power generation. In households, it’s used in utensils like spoons and forks, water bottles, and cups. Construction applications include silver frames, plates, and handrails for automatic doors, elevators, and escalators. It’s also utilized in industrial settings for bolts, nuts, automotive components, labor-saving parts, and cleaning machine parts. However, due to its price, which is influenced by raw material costs, SAE 430 stainless steel is sometimes substituted for 304 304 stainless steel to reduce expenses. 430 304 stainless steel, lacking nickel, offers less corrosion resistance than 304 304 stainless steel but is more cost-effective and magnetic.
Properties of SAE 304 Stainless Steel
304 304 stainless steel is notably stretchable with strong viscosity, ideal for intricate deep-drawn or bent products. It’s weldable to iron and typically used as thin sheets. Despite being non-magnetic due to its nickel content, magnetic properties can be induced through certain processes. Cold working can harden the material, increasing strength but complicating processing.
Types of SAE 304 Stainless Steel
Several variants of SAE 304 304 stainless steel exist, each with unique characteristics:
- 304L: An ultra-low carbon version with enhanced resistance to intergranular corrosion.
- 304N: Includes nitrogen to maintain ductility while increasing strength.
- 304 Cu: Contains added copper to prevent work hardening and improve deep-drawing properties.
- 302: Similar to 304 stainless steel but with higher carbon content, prone to work hardening and intergranular corrosion.
- 303S: A 304 stainless steel variant with added sulfur for improved machinability.
Manufacturing Process of SAE 304 Stainless Steel
The manufacturing process begins by melting iron and other raw materials in a furnace, followed by refining to remove impurities and carbon. The molten steel is cast into forms like plates, wire rods, bars, or shapes. This cast stainless steel is then thinned using rolling processes, including hot and cold rolling, followed by heat treatment, pickling, optional cold rolling, polishing, and inspection.