‌S21800 Stainless Steel Plate Technical Manual

S21800 is a nitrogen-strengthened austenitic stainless alloy with exceptional corrosion resistance, high hardness, and superior wear resistance. Its unique composition (high Mn, Cr, and N) provides:

‌‌Enhanced strength‌:2x yield strength of 304/316 stainless steels‌.
‌‌Outstanding corrosion resistance‌:Exceeds 316 in chloride environments‌.
‌‌‌High-temperature stability‌:Maintains mechanical properties up to 1000°C‌.
‌‌Good machinability‌:Suitable for complex forming and welding‌.

Chemical Composition (wt%)

Parameter	Value/Range
Thickness	6mm–300mm (plate)
Hardness (HB)	200–241 (annealed state)‌
Density (g/cm³)	7.8
Yield Strength (MPa)	240–590
Tensile Strength (MPa)	690–860
Elongation (%)	25–65

Element	Content (%)
C	≤0.10
Si	3.50–4.50
Mn	7.00–9.00
P	≤0.04
S	≤0.03
Cr	16.0–18.0
Ni	8.00–9.00
N	0.08–0.20
Note: Mo ≤0.18% (varies by standard)‌67

S21800 stainless steel plate is a high-performance austenitic stainless steel renowned for its exceptional corrosion resistance, high strength, and excellent weldability. It is widely used in the chemical, aerospace, and medical device industries. The following is a detailed analysis of its performance characteristics and applications:

1. Performance Characteristics
1.1 Corrosion Resistance
S21800 performs exceptionally well in a variety of acidic and alkaline environments, particularly in chloride-containing media, where its pitting corrosion resistance surpasses that of 316 stainless steel. It is suitable for demanding environments such as the chemical and marine engineering sectors. Its high chromium content (18%-20%) and low carbon content (≤0.03%) further enhance its corrosion resistance.

1.2 Mechanical Properties
This material boasts high strength, with a tensile strength exceeding 485 MPa and an elongation exceeding 40%, making it suitable for the fabrication of complex shapes. Its outstanding high-temperature resistance, maintaining stable performance at temperatures between 600°C and 800°C, makes it suitable for high-temperature equipment.

1.3 Processing and Weldability
S21800 has excellent ductility and can be formed by cold and hot rolling, allowing for wide design freedom. It also offers excellent weldability and is compatible with processes such as TIG and MIG. The weld strength approaches that of the parent material, eliminating the need for post-weld heat treatment, significantly reducing manufacturing costs.

2. Main Applications
2.1 Chemical and Petroleum Industries
Used in reactors, pipelines, valves, and other equipment, its corrosion resistance ensures long-term operational safety and is particularly suitable for high-sulfur oil and gas fields and chemical production.

2.2 Aerospace
Manufacturing engine components, airframe structures, and high-temperature parts, its high strength and high-temperature resistance meet the demands of demanding operating conditions.

2.3 Medical Devices and Food Processing
Used in surgical instruments, implants, and food containers, its biocompatibility and hygienic standards ensure medical and food safety.

2.4 Construction and Marine Engineering
Used in bridges, support frames, and desalination equipment, its high strength and weather resistance enhance structural reliability.