SUS304L: A standard austenitic steel grade with the widest range of applications; features excellent corrosion resistance, heat resistance, low-temperature strength, and mechanical properties; possesses a single-phase austenitic structure and does not harden through heat treatment (non-magnetic; operating temperature range: -196°C to 800°C).
SUS304Cu: An austenitic stainless steel based on a 17Cr-7Ni-2Cu composition; offers excellent formability-particularly in wire drawing-and good resistance to age-hardening cracking; corrosion resistance is comparable to that of SUS304.
SUS316: Exhibits exceptional corrosion resistance and high-temperature strength, making it suitable for use under harsh conditions; features good work-hardening characteristics and is non-magnetic. Suitable for seawater equipment, chemical processing, dyes, papermaking, oxalic acid and fertilizer production, photography, the food industry, and coastal facilities.
SUS316L: Contains added Molybdenum (2–3%), resulting in superior corrosion resistance and high-temperature strength; the lower carbon content compared to SUS316 provides better resistance to intergranular corrosion and higher high-temperature creep strength. Suitable for harsh conditions; features good work-hardening characteristics and is non-magnetic. Applications include seawater equipment, chemical processing, dyes, papermaking, oxalic acid and fertilizer production, photography, the food industry, and coastal facilities.
SUS321: Contains added Titanium (Ti) to the 304 grade, providing excellent resistance to intergranular corrosion as well as superior high-temperature strength and oxidation resistance; however, it entails higher costs and poorer workability compared to SUS304. Applications include heat-resistant components, automotive and aircraft exhaust systems, boiler covers and piping, chemical processing units, and heat exchangers.
Note that chromium-nickel austenitic stainless steel is the most commonly used corrosion-resistant material, yet intergranular corrosion is the most frequent cause of failure for containers made from this material. Intergranular corrosion significantly weakens the bonding forces between grains, potentially leading to a complete loss of mechanical strength in severe cases.
SUH409H: Offers good workability and weldability, as well as excellent high-temperature oxidation resistance; capable of withstanding temperatures ranging from room temperature up to 575°C. Widely used in automotive exhaust systems.
SUS409L: Features controlled carbon and nitrogen content, resulting in excellent weldability, formability, and corrosion resistance. It contains 11% chromium and maintains a ferritic structure (BCC) at both high and ambient temperatures. Due to the addition of titanium, it exhibits good oxidation and corrosion resistance at temperatures up to 750°C.
SUS410: A representative martensitic grade characterized by high strength and hardness (magnetic); it has poor corrosion resistance and is unsuitable for highly corrosive environments. It features low carbon content and good workability, and its surface can be hardened through heat treatment.
SUS420J2: A representative martensitic grade characterized by high strength and hardness (magnetic); it offers good wear resistance but has poor corrosion resistance and formability. Mechanical properties can be improved through heat treatment. Widely used for cutting tools, nozzles, valves, rulers, and cutlery.
SUS430: Features a low thermal expansion rate, good formability, and excellent oxidation resistance; suitable for heat-resistant appliances, burners, home appliances, general-purpose cutlery, and kitchen sinks. Low cost and good workability make it an ideal alternative to SUS304. It offers good corrosion resistance and is a typical ferritic stainless steel that cannot be hardened by heat treatment.
