Stainless Steel
- Home
- Stainless Steel
Stainless Steel
Stainless steel has many desirable properties that contribute greatly to its widespread application in the making of parts and components across many industrial sectors. Above all, because of its chromium content, it is extremely resistant to corrosion. The 10.5% minimum content makes steel approximately 200 times more resistant to corrosion than steels without chromium. Other favorable properties for consumers are its high strength and durability, its high and low temperature resistance, increased formability and easy fabrication, low maintenance, long-lasting, attractive appearance and it is environmentally friendly and recyclable. Once stainless steel is put into service, it does not need to be treated, coated or painted.
| Grade | UNS Number | Composition (%) | Density (g/cm³) | Melting Point (°C) | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Applications |
|---|---|---|---|---|---|---|---|---|
| 304 | S30400 | Cr 18-20, Ni 8-10.5, Mn ≤ 2, Si ≤ 1, N ≤ 0.10, Fe balance, C ≤ 0.08 | 8.0 | 1399-1454 | 515-750 | 205-345 | 40-60 | Kitchen equipment, chemical containers, heat exchangers, architectural trim |
| 304L | S30403 | Cr 18-20, Ni 8-12, Mn ≤ 2, Si ≤ 1, N ≤ 0.10, Fe balance, C ≤ 0.03 | 8.0 | 1399-1454 | 485-675 | 170-310 | 40-60 | Chemical processing, food industry, brewing, storage tanks |
| 316 | S31600 | Cr 16-18, Ni 10-14, Mo 2-3, Mn ≤ 2, Si ≤ 1, N ≤ 0.10, Fe balance, C ≤ 0.08 | 8.0 | 1371-1400 | 515-690 | 205-300 | 40-60 | Marine equipment, chemical processing, medical devices, food preparation equipment |
| 316L | S31603 | Cr 16-18, Ni 10-14, Mo 2-3, Mn ≤ 2, Si ≤ 1, N ≤ 0.10, Fe balance, C ≤ 0.03 | 8.0 | 1371-1400 | 485-675 | 170-310 | 40-60 | Marine environments, pharmaceutical equipment, food and beverage industry, lab equipment |
| 321 | S32100 | Cr 17-19, Ni 9-12, Ti ≥ 5xC, Mn ≤ 2, Si ≤ 1, N ≤ 0.10, Fe balance, C ≤ 0.08 | 8.0 | 1400-1427 | 515-690 | 205-275 | 35-55 | Aerospace, chemical processing, high temperature applications, expansion joints |
| 430 | S43000 | Cr 16-18, Ni ≤ 0.75, Mn ≤ 1, Si ≤ 1, N ≤ 0.10, Fe balance, C ≤ 0.12 | 7.7 | 1425-1510 | 450-700 | 275-450 | 20-30 | Automotive trim, dishwashers, nitric acid tanks, appliances |
| 409 | S40900 | Cr 10.5-11.75, Ni ≤ 0.5, Mn ≤ 1, Si ≤ 1, Ti 0.5 max, Fe balance, C ≤ 0.08 | 7.7 | 1425-1510 | 380-620 | 170-310 | 20-30 | Automotive exhaust systems, heating systems, agricultural equipment |
| 904L | N08904 | Cr 19-23, Ni 23-28, Mo 4-5, Cu 1-2, Mn ≤ 2, Si ≤ 1, N ≤ 0.10, Fe balance, C ≤ 0.02 | 7.95 | 1350-1400 | 490-690 | 220-300 | 35-40 | Chemical processing, oil and gas industry, seawater cooling devices, pollution control |
There are many numerical grading systems for stainless steel, designated according to their composition, physical properties, and applications. Each type of stainless steel is classified by its series number and then assigned a numerical grade. The most popular series numbers are 200, 300, 400, 600, and 2000. The most common grades are type 304 and 316 that consist of austenitic chromium-nickel alloys. Cutlery grade stainless steels are found in the 400 Series, which is derived from ferritic and martensitic chromium alloys. Type 420 is known as surgical steel, and type 440 is known as razor blade steel.
| EN Number | Alloy Designation | Composition (%) | Density (g/cm³) | Melting Point (°C) | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Applications |
|---|---|---|---|---|---|---|---|---|
| EN 1.4301 | X5CrNi18-10 | C ≤ 0.07, Cr 17.5-19.5, Ni 8.0-10.5 | 7.90 | 1400-1450 | 500-700 | 190-250 | 45-60 | Kitchenware, food processing, chemical containers |
| EN 1.4404 | X2CrNiMo17-12-2 | C ≤ 0.03, Cr 16.5-18.5, Ni 10.0-13.0, Mo 2.0-2.5 | 7.98 | 1375-1400 | 500-700 | 200-300 | 40-50 | Chemical equipment, marine applications |
| EN 1.4541 | X6CrNiTi18-10 | C ≤ 0.08, Cr 17.0-19.0, Ni 9.0-12.0, Ti 5xC to 0.70 | 7.90 | 1400-1450 | 500-700 | 200-250 | 35-50 | Exhaust systems, heat exchangers |
| EN 1.4571 | X6CrNiMoTi17-12-2 | C ≤ 0.08, Cr 16.5-18.5, Ni 10.5-13.5, Mo 2.0-2.5, Ti 5xC to 0.70 | 7.98 | 1375-1400 | 500-700 | 210-290 | 35-50 | Chemical equipment, marine environments |
| EN 1.4401 | X5CrNiMo17-12-2 | C ≤ 0.07, Cr 16.5-18.5, Ni 10.0-13.0, Mo 2.0-2.5 | 7.98 | 1375-1400 | 500-700 | 200-300 | 40-50 | Chemical processing, medical instruments |
| EN 1.4307 | X2CrNi18-9 | C ≤ 0.03, Cr 17.0-19.0, Ni 8.0-10.0 | 7.90 | 1400-1450 | 500-700 | 190-250 | 45-60 | Architectural applications, food processing |
| EN 1.4016 | X6Cr17 | C ≤ 0.08, Cr 16.0-18.0 | 7.70 | 1480-1530 | 400-600 | 240-400 | 20-30 | Automotive trim, kitchen appliances |
The family of stainless steels is primarily classified into four main categories based upon their crystal microstructure.
FERRITIC
Ferritic steels are the 400 Grade stainless steels noted for their high chromium content, which can range from 10.5% to 27%. They have magnetic properties, too, offers good ductility, tensile-property stability, and resistance to corrosion, thermal fatigue, and stress-corrosion cracking.