210 Stainless Steel: Properties and Key Applications

210 Stainless Steel is classified as an austenitic stainless steel, known for its excellent corrosion resistance and good mechanical properties. This grade is primarily alloyed with chromium (Cr), nickel (Ni), and molybdenum (Mo), which significantly enhance its overall performance in various environments. The typical composition of 210 Stainless Steel includes approximately 18% chromium and 8% nickel, which contribute to its austenitic structure, providing excellent toughness and ductility.

Comprehensive Overview

The most significant characteristics of 210 Stainless Steel include its high resistance to oxidation and corrosion, particularly in acidic environments. It also exhibits good weldability and formability, making it suitable for various manufacturing processes. The steel's ability to maintain strength at elevated temperatures further enhances its utility in high-temperature applications.

Advantages:
- Corrosion Resistance: Excellent resistance to a wide range of corrosive environments, including acidic and alkaline solutions.
- Mechanical Properties: Good tensile strength and ductility, allowing for effective forming and shaping.
- Weldability: Suitable for various welding processes without significant loss of mechanical properties.

Limitations:
- Cost: Higher alloy content can lead to increased material costs compared to lower-grade steels.
- Work Hardening: While it can be formed easily, it may work-harden quickly, requiring careful handling during machining.

Historically, 210 Stainless Steel has found applications in industries such as food processing, chemical processing, and marine environments, where its unique properties are highly valued. Its market position is strong, particularly in sectors that require materials with high corrosion resistance and durability.

Alternative Names, Standards, and Equivalents

Standard Organization	Designation/Grade	Country/Region of Origin	Notes/Remarks
UNS	S21000	USA	Closest equivalent to AISI 304 with minor compositional differences.
AISI/SAE	210	USA	Similar to 304 but with enhanced corrosion resistance.
ASTM	A240	USA	Standard specification for chromium and chromium-nickel stainless steel plate, sheet, and strip.
EN	1.4301	Europe	Equivalent to AISI 304, with slight variations in composition.
JIS	SUS 304	Japan	Closely related to AISI 304, often used interchangeably.

The differences between 210 Stainless Steel and its equivalents, such as AISI 304, primarily lie in the specific alloying elements and their concentrations, which can affect performance in specific environments. For instance, 210 may offer better resistance to pitting in chloride environments compared to 304.

Key Properties

Chemical Composition

Element (Symbol and Name)	Percentage Range (%)
Cr (Chromium)	18.0 - 20.0
Ni (Nickel)	8.0 - 10.0
Mo (Molybdenum)	0.0 - 2.0
C (Carbon)	≤ 0.08
Mn (Manganese)	2.0 - 2.5
Si (Silicon)	≤ 1.0
P (Phosphorus)	≤ 0.045
S (Sulfur)	≤ 0.03

The primary role of chromium in 210 Stainless Steel is to enhance corrosion resistance, while nickel contributes to the steel's toughness and ductility. Molybdenum improves resistance to pitting and crevice corrosion, particularly in chloride environments.

Mechanical Properties

Property	Condition/Temper	Test Temperature	Typical Value/Range (Metric)	Typical Value/Range (Imperial)	Reference Standard for Test Method
Tensile Strength	Annealed	Room Temp	520 - 750 MPa	75 - 109 ksi	ASTM E8
Yield Strength (0.2% offset)	Annealed	Room Temp	210 - 310 MPa	30 - 45 ksi	ASTM E8
Elongation	Annealed	Room Temp	40 - 50%	40 - 50%	ASTM E8
Hardness (Rockwell B)	Annealed	Room Temp	70 - 90 HRB	70 - 90 HRB	ASTM E18
Impact Strength	Charpy V-notch	-20 °C	40 - 60 J	29 - 44 ft-lbf	ASTM E23

The combination of these mechanical properties makes 210 Stainless Steel suitable for applications requiring good strength and ductility, such as structural components and pressure vessels.

Physical Properties

Property	Condition/Temperature	Value (Metric)	Value (Imperial)
Density	Room Temp	7.93 g/cm³	0.286 lb/in³
Melting Point	-	1400 - 1450 °C	2552 - 2642 °F
Thermal Conductivity	Room Temp	16 W/m·K	9.3 BTU·in/h·ft²·°F
Specific Heat Capacity	Room Temp	500 J/kg·K	0.12 BTU/lb·°F
Electrical Resistivity	Room Temp	0.72 µΩ·m	0.00000072 Ω·m

The density of 210 Stainless Steel indicates its robustness, while its thermal conductivity and specific heat capacity are critical for applications involving heat transfer, such as heat exchangers.

Corrosion Resistance

Corrosive Agent	Concentration (%)	Temperature (°C/°F)	Resistance Rating	Notes
Chlorides	3-5	20-60 °C / 68-140 °F	Good	Risk of pitting corrosion
Sulfuric Acid	10-20	20-40 °C / 68-104 °F	Fair	Susceptible to SCC
Acetic Acid	5-10	20-60 °C / 68-140 °F	Good	Generally resistant
Sea Water	-	Ambient	Excellent	Highly resistant

210 Stainless Steel exhibits excellent resistance to a variety of corrosive environments, particularly in marine applications. However, it is susceptible to stress corrosion cracking (SCC) in the presence of chlorides, especially at elevated temperatures. Compared to grades like 316 Stainless Steel, which contains molybdenum for enhanced pitting resistance, 210 may not perform as well in highly corrosive environments.

Heat Resistance

Property/Limit	Temperature (°C)	Temperature (°F)	Remarks
Max Continuous Service Temp	800 °C	1472 °F	Suitable for high-temperature applications
Max Intermittent Service Temp	870 °C	1598 °F	Can withstand short-term exposure
Scaling Temperature	900 °C	1652 °F	Risk of oxidation at higher temperatures

At elevated temperatures, 210 Stainless Steel maintains its strength and corrosion resistance, making it suitable for applications such as furnace components and heat exchangers. However, prolonged exposure to temperatures above 800 °C can lead to oxidation and scaling.

Fabrication Properties

Weldability

Welding Process	Recommended Filler Metal (AWS Classification)	Typical Shielding Gas/Flux	Notes
TIG	ER308L	Argon	Good for thin sections
MIG	ER308L	Argon + CO2	Suitable for thicker sections
Stick	E308L	-	Requires careful heat control

210 Stainless Steel is generally considered to have good weldability. However, preheating and post-weld heat treatment may be necessary to minimize the risk of cracking. Proper filler metals should be selected to match the base material's properties.

Machinability

Machining Parameter	210 Stainless Steel	AISI 1212	Notes/Tips
Relative Machinability Index	50	100	Moderate machinability
Typical Cutting Speed (Turning)	30 m/min	60 m/min	Use carbide tools for best results

Machining 210 Stainless Steel can be challenging due to its work-hardening characteristics. It is advisable to use sharp tools and appropriate cutting fluids to enhance performance.

Formability

210 Stainless Steel exhibits good formability, making it suitable for cold and hot forming processes. However, it may work-harden quickly, necessitating careful control of the forming process to avoid cracking.

Heat Treatment

Treatment Process	Temperature Range (°C/°F)	Typical Soaking Time	Cooling Method	Primary Purpose / Expected Result
Annealing	1000 - 1100 °C / 1832 - 2012 °F	1-2 hours	Air or Water	Relieve stresses, improve ductility

During heat treatment, 210 Stainless Steel undergoes metallurgical transformations that enhance its ductility and reduce residual stresses. Proper heat treatment is crucial for achieving optimal mechanical properties.

Typical Applications and End Uses

Industry/Sector	Specific Application Example	Key Steel Properties Utilized in this Application	Reason for Selection (Brief)
Food Processing	Food handling equipment	Corrosion resistance, hygiene	Non-reactive, easy to clean
Chemical Processing	Storage tanks	High strength, corrosion resistance	Durability in harsh environments
Marine	Boat fittings	Excellent corrosion resistance	Long-lasting in saltwater
Pharmaceutical	Equipment and piping	Cleanliness, corrosion resistance	Compliance with health standards

In food processing, 210 Stainless Steel is chosen for its non-reactive properties, ensuring that food products remain uncontaminated. In marine applications, its resistance to saltwater corrosion makes it ideal for boat fittings and components.

Important Considerations, Selection Criteria, and Further Insights

Feature/Property	210 Stainless Steel	AISI 304 Stainless Steel	AISI 316 Stainless Steel	Brief Pro/Con or Trade-off Note
Key Mechanical Property	Good tensile strength	Good tensile strength	Higher tensile strength	316 offers better corrosion resistance
Key Corrosion Aspect	Good in many environments	Good in many environments	Excellent in chlorides	316 is preferred for marine applications
Weldability	Good	Excellent	Good	304 is easier to weld
Machinability	Moderate	Good	Moderate	304 is easier to machine
Formability	Good	Excellent	Good	304 has better formability
Approx. Relative Cost	Moderate	Moderate	Higher	316 is more expensive
Typical Availability	Common	Very Common	Common	304 is widely available

When selecting 210 Stainless Steel, considerations such as cost-effectiveness, availability, and specific application requirements are crucial. While it offers a balance of properties, alternatives like AISI 316 may be more suitable for highly corrosive environments, albeit at a higher cost.

In summary, 210 Stainless Steel is a versatile material that combines good mechanical properties with excellent corrosion resistance, making it suitable for a wide range of applications across various industries. Its unique characteristics and performance in specific environments make it a valuable choice for engineers and manufacturers alike.