Have you ever struggled with stubborn rust stains on kitchenware? Or faced headaches from industrial equipment corrosion? Stainless steel SUS, with its exceptional corrosion resistance, is revolutionizing both domestic and industrial applications through its outstanding performance and versatility.
SUS, an abbreviation for "Steel Use Stainless," represents more than just metal—it symbolizes durability and quality. This iron-based alloy contains at least 10.5% chromium (Cr), which provides its remarkable corrosion resistance. Additional elements like carbon (C), nickel (Ni), molybdenum (Mo), manganese (Mn), and silicon (Si) can be added to tailor properties for specific applications.
According to Japanese Industrial Standards (JIS), SUS classifications follow a "SUS+three digits+symbol" naming convention (e.g., SUS304, SUS410, SUS316L). The first digit indicates the steel category: 300-series for austenitic, 400-series for ferritic/martensitic, and 600-series for precipitation-hardening stainless steels. Suffix letters denote special properties—"L" for low carbon (improved corrosion resistance), "N" for nitrogen-added (enhanced strength), and "Ti" for titanium-added (prevents intergranular corrosion).
The chromium content forms a protective passive oxide layer that prevents rust formation. This self-healing film makes SUS ideal for kitchenware, food processing equipment, and chemical industry applications. However, in high-chloride or extreme pH environments, specialized grades like SUS316 (with molybdenum) are recommended.
Maintaining strength up to 500°C, SUS serves well in automotive brake systems, boiler components, and high-temperature piping. Special high-temperature grades like SUS304H and SUS310S offer enhanced performance for extreme conditions.
This property makes SUS perfect for thermal insulation applications like vacuum flasks and food containers, though unsuitable for heat dissipation components.
Carbon content and heat treatment allow SUS to achieve high strength for structural components, fasteners, and springs in construction and machinery.
While not suitable for conductive applications, this characteristic benefits resistance heating elements.
The most common type, containing 16-20% Cr and 8%+ Ni. SUS304 ("18-8" steel) offers balanced properties for kitchenware, medical devices, and industrial equipment. Variants include:
- SUS304L: Low-carbon version for welded structures
- SUS316: Molybdenum-added for marine environments
- SUS316L: Low-carbon marine grade
- SUS321: Titanium-stabilized for high-temperature service
Chromium-containing (11-32%) but nickel-free, offering cost-effective solutions like SUS430 for kitchen sinks and appliances. While less corrosion-resistant than austenitic grades, they provide good formability and magnetic properties.
Combining austenitic and ferritic structures, these grades (e.g., SUS329J4L) deliver double the strength of standard austenitic steels with excellent chloride resistance, making them ideal for marine applications.
With 12-18% Cr and 0.1-0.4% C, these heat-treatable grades (like SUS410) achieve high hardness for cutting tools and mechanical components, though with reduced corrosion resistance.
Grades like SUS630 balance strength and corrosion resistance through heat treatment, serving aerospace and high-performance engineering applications.
Key considerations include environmental conditions, mechanical requirements, fabrication needs, and budget constraints. Proper material selection enhances product longevity, reduces maintenance costs, and improves operational efficiency across domestic and industrial applications.