Stainless steel is an iron-based alloy containing at least 10.5% chromium. Chromium forms a protective chromium oxide layer on the surface, preventing rust from penetrating the iron.Stainless steel can be classified into duplex structure classes y single heat-treatment classes, which fall under the same general category for most types. The numbering system divides stainless steel into five categories: martensitic, austenitic, ferritic, duplex, and precipitation-hardening.In this article, we will examine the different types of stainless steel.
Acero inoxidable martensítico
Martensitic stainless steels are a class of stainless steel whose properties can be adjusted through heat treatment (quenching, tempering). These steels primarily consist of iron and carbon (up to ~2 wt.%), with chromium content ranging from 10.5% to 18% and carbon content not exceeding 1.2%.
For Grade 403, no additional parameters are specified—it is a basic martensitic stainless steel. Other martensitic steels (e.g., 403, 410, and the 400 series) are considered hardenable.
Applications:
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Jet engines
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Gas turbines
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Valve components
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Cutlery
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Petrochemical equipment
Key Mechanical Properties:
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Moderate work-hardening rate
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Heat-treatable
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Good ductility and toughness
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High tensile strength
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Good creep and fatigue resistance
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Magnetic
Acero inoxidable austenítico
The most common type of chromium alloy, austenitic stainless steel has a face-centered cubic (FCC) crystal structure, similar to high-temperature iron. The primary alloying elements are chromium-nickel (Cr-Ni) y chromium-manganese-nitrogen (Cr-Mn-N), categorized by application.
Composition:
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16–26% chromium
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≤0.15% carbon
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Up to 35% nickel (for cold-working and strain hardening)
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Manganese (≤1/7 Mn per standards)
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Silicon (0.75–3% for high-temperature strengthening)
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Additional elements (e.g., sulfur, nitrogen, molybdenum, selenium, copper)
Magnetic austenitic grades: 201, 202, 205.
Non-magnetic grades: 304 (industrial standard, ≥8% nickel).
Applications:
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Appliances
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Screws and undercut components
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Chemical mixing tanks
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Pressure vessels
Mechanical Properties:
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Excellent work-hardening rate
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Superior ductility and toughness
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High tensile strength
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Good creep and fatigue resistance
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Scale resistance (up to 650°C)
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Moderate heat resistance (≤650°C)
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Excellent weldability
Acero inoxidable ferrítico
Ferritic stainless steel has a body-centered cubic (BCC) structure, with 10.5–30% chromium and ≤0.2% carbon. Common alloying elements include molybdenum, silicon, aluminum, titanium, and niobium.
Basic grade: 430.
Enhanced grades: 434 (standard), 409 (titanium-stabilized), 439, 444 (super ferritic).
- Food processing equipment
- Chloride solution pipelines
- Heat exchangers (≤250°C)
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Automotive interiors
Mechanical Properties:
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Low work-hardening rate
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Moderate ductility and toughness
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High tensile strength
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Good creep/fatigue resistance at low temperatures
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Moderate corrosion resistance
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Good heat resistance
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Poor weldability
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Magnetic
Duplex Stainless Steel
Duplex stainless steel combines ferritic (BCC) y austenitic (FCC) structures. It offers corrosion resistance comparable to Grade 316 austenitic steel but with higher tensile strength and improved stress-corrosion cracking resistance.
Composition:
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22–26% chromium
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4–7% nickel
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≤0.6% copper
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0.15–0.25% nitrogen
Categories:
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Lean duplex (2304)
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Standard duplex (2205)
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Super duplex (2507)
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Hyper duplex (Zeron 100)
Applications:
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Oil & gas
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Chloride water treatment
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Seawater desalination
Mechanical Properties:
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High work-hardening rate
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Non-heat-treatable
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Good ductility/toughness
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Excellent corrosion resistance
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Moderate weldability
Other Notable Grades
201 Stainless Steel
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Composición: Cr-Mn-N alloy (16–18% Cr, 3.5–5.5% Ni).
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Applications: Food handling, architectural components.
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Properties: Non-magnetic (annealed), cold-work hardenable.
2507 (Super Duplex)
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Composición: 25% Cr, 7% Ni, 4% Mo.
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Applications: Desalination plants, chemical processing.
304/304L/304H
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304: General-purpose (18% Cr, 8% Ni).
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304L: Low-carbon variant for welding.
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304H: High-temperature stability.
316/316L
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Molybdenum-enhanced for corrosion resistance.
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Applications: Marine, chemical processing.
430 (Ferritic)
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Cost-effective, moderate corrosion resistance.
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Applications: Automotive exhausts, heat exchangers.
Resumen
This article detailed stainless steel types, grades, and properties. For further inquiries, contact DAXUN for manufacturing services or a free quote.
Descargo de responsabilidad: The content is for informational purposes only. DAXUN does not guarantee accuracy. Specifications depend on supplier compliance. Refer to our Terms & Conditions for details.
