1.0718 Steel (11SMnPb30): Properties and Key Applications
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Table Of Content
Table Of Content
1.0718 Steel (11SMnPb30) is a low-alloy steel grade primarily classified as a free-cutting steel. It is characterized by its excellent machinability, making it a preferred choice in applications where precision and efficiency in machining are critical. The primary alloying elements in 1.0718 include manganese (Mn) and lead (Pb), which enhance its mechanical properties and workability. The presence of lead significantly improves the steel's machinability, allowing for smoother cutting and reduced tool wear.
Comprehensive Overview
1.0718 Steel is known for its unique combination of properties that make it suitable for various engineering applications. Its key characteristics include high strength, good ductility, and excellent machinability. The addition of lead not only improves machinability but also contributes to the steel's ability to maintain dimensional stability during machining processes.
| Property | Description |
|---|---|
| Classification | Low-alloy free-cutting steel |
| Primary Alloying Elements | Manganese (Mn), Lead (Pb) |
| Key Characteristics | High strength, excellent machinability, good ductility |
Advantages:
- Exceptional machinability due to lead content.
- Good strength-to-weight ratio.
- Suitable for precision components and complex geometries.
Limitations:
- Lead content may pose environmental and health concerns during machining.
- Lower corrosion resistance compared to stainless steels.
- Limited high-temperature performance.
Historically, 1.0718 has been widely used in the automotive and manufacturing industries for producing components such as gears, shafts, and precision fittings. Its market position is strong due to its favorable balance of cost and performance, making it a common choice in various applications.
Alternative Names, Standards, and Equivalents
| Standard Organization | Designation/Grade | Country/Region of Origin | Notes/Remarks |
|---|---|---|---|
| UNS | 11SMnPb30 | USA | Closest equivalent to AISI 1212 |
| AISI/SAE | 1212 | USA | Minor compositional differences |
| DIN | 1.0718 | Germany | Commonly used in Europe |
| EN | 11SMnPb30 | Europe | Free-cutting steel designation |
| JIS | S12PB | Japan | Similar properties, different standards |
| ISO | 11SMnPb30 | International | Standardized designation |
The differences between these equivalent grades often lie in the specific percentages of alloying elements, which can affect properties like machinability and strength. For instance, while AISI 1212 is similar, it may not contain the same level of lead, impacting its machinability.
Key Properties
Chemical Composition
| Element | Percentage Range (%) |
|---|---|
| C (Carbon) | 0.10 - 0.15 |
| Mn (Manganese) | 1.20 - 1.50 |
| Pb (Lead) | 0.15 - 0.35 |
| Si (Silicon) | 0.15 - 0.40 |
| P (Phosphorus) | ≤ 0.04 |
| S (Sulfur) | ≤ 0.05 |
The primary alloying elements in 1.0718 Steel play crucial roles:
- Manganese (Mn): Enhances strength and hardness while improving hardenability.
- Lead (Pb): Significantly improves machinability, allowing for smoother cutting and reduced tool wear.
- Carbon (C): Contributes to overall strength and hardness, though in lower amounts compared to other alloy steels.
Mechanical Properties
| Property | Condition/Temper | Typical Value/Range (Metric) | Typical Value/Range (Imperial) | Reference Standard for Test Method |
|---|---|---|---|---|
| Tensile Strength | Annealed | 600 - 700 MPa | 87 - 102 ksi | ASTM E8 |
| Yield Strength (0.2% offset) | Annealed | 350 - 450 MPa | 51 - 65 ksi | ASTM E8 |
| Elongation | Annealed | 20 - 30% | 20 - 30% | ASTM E8 |
| Hardness (Brinell) | Annealed | 150 - 180 HB | 150 - 180 HB | ASTM E10 |
| Impact Strength (Charpy) | -40°C | 30 - 40 J | 22 - 30 ft-lbf | ASTM E23 |
The mechanical properties of 1.0718 Steel make it particularly suitable for applications requiring high strength and good ductility. Its excellent machinability allows for efficient production of complex parts, while its yield strength ensures structural integrity under load.
Physical Properties
| Property | Condition/Temperature | Value (Metric) | Value (Imperial) |
|---|---|---|---|
| Density | - | 7.85 g/cm³ | 0.284 lb/in³ |
| Melting Point | - | 1420 - 1460 °C | 2590 - 2660 °F |
| Thermal Conductivity | 20°C | 45 W/m·K | 31 BTU·in/(hr·ft²·°F) |
| Specific Heat Capacity | 20°C | 460 J/kg·K | 0.11 BTU/lb·°F |
| Electrical Resistivity | 20°C | 0.0006 Ω·m | 0.000035 Ω·in |
Key physical properties such as density and thermal conductivity are significant for applications where weight and heat dissipation are critical. The density of 1.0718 Steel makes it suitable for lightweight components, while its thermal conductivity allows for effective heat management in mechanical systems.
Corrosion Resistance
| Corrosive Agent | Concentration (%) | Temperature (°C/°F) | Resistance Rating | Notes |
|---|---|---|---|---|
| Chlorides | 3-10 | 20-60 °C (68-140 °F) | Fair | Risk of pitting |
| Acids (Sulfuric) | 5-20 | 20-40 °C (68-104 °F) | Poor | Susceptible to SCC |
| Alkaline Solutions | 1-5 | 20-60 °C (68-140 °F) | Fair | Moderate resistance |
1.0718 Steel exhibits moderate corrosion resistance, particularly in environments with chlorides and acidic conditions. It is susceptible to localized corrosion such as pitting and stress corrosion cracking (SCC). Compared to stainless steels like AISI 304, which offer superior corrosion resistance, 1.0718 is less suitable for harsh environments.
Heat Resistance
| Property/Limit | Temperature (°C) | Temperature (°F) | Remarks |
|---|---|---|---|
| Max Continuous Service Temp | 300 °C | 572 °F | Suitable for moderate temperatures |
| Max Intermittent Service Temp | 350 °C | 662 °F | Short-term exposure only |
| Scaling Temperature | 400 °C | 752 °F | Risk of oxidation beyond this limit |
At elevated temperatures, 1.0718 Steel maintains its strength but may experience oxidation and scaling. It is not recommended for applications requiring prolonged exposure to high temperatures, as its mechanical properties can degrade.
Fabrication Properties
Weldability
| Welding Process | Recommended Filler Metal (AWS Classification) | Typical Shielding Gas/Flux | Notes |
|---|---|---|---|
| MIG | ER70S-6 | Argon + CO2 | Preheat recommended |
| TIG | ER70S-2 | Argon | Good for thin sections |
| Stick | E7018 | - | Requires careful handling |
1.0718 Steel is generally weldable, but the presence of lead can complicate the process. Preheating is often recommended to minimize the risk of cracking. Post-weld heat treatment may also be necessary to relieve stresses.
Machinability
| Machining Parameter | 1.0718 Steel | AISI 1212 | Notes/Tips |
|---|---|---|---|
| Relative Machinability Index | 100 | 130 | 1.0718 is slightly less machinable |
| Typical Cutting Speed (Turning) | 80 m/min | 100 m/min | Adjust tooling for optimal performance |
1.0718 Steel offers good machinability, though it is slightly less favorable than AISI 1212. Optimal cutting speeds and tooling should be selected to enhance performance and reduce wear.
Formability
1.0718 Steel exhibits good formability, making it suitable for cold and hot forming processes. However, care should be taken to avoid excessive work hardening, which can lead to cracking during bending operations. Recommended bend radii should be adhered to for optimal results.
Heat Treatment
| Treatment Process | Temperature Range (°C/°F) | Typical Soaking Time | Cooling Method | Primary Purpose / Expected Result |
|---|---|---|---|---|
| Annealing | 600 - 700 °C / 1112 - 1292 °F | 1 - 2 hours | Air or water | Softening, improved machinability |
| Quenching | 850 - 900 °C / 1562 - 1652 °F | 30 minutes | Oil or water | Hardening, increased strength |
| Tempering | 400 - 600 °C / 752 - 1112 °F | 1 hour | Air | Reducing brittleness, improving toughness |
Heat treatment processes significantly impact the microstructure and properties of 1.0718 Steel. Annealing enhances machinability, while quenching and tempering improve strength and toughness.
Typical Applications and End Uses
| Industry/Sector | Specific Application Example | Key Steel Properties Utilized in this Application | Reason for Selection (Brief) |
|---|---|---|---|
| Automotive | Gears | High strength, excellent machinability | Precision components |
| Manufacturing | Shafts | Good ductility, strength | Complex geometries |
| Aerospace | Fasteners | High strength-to-weight ratio | Lightweight and durable |
Other applications include:
- Precision fittings
- Hydraulic components
- Machine parts
1.0718 Steel is chosen for these applications due to its favorable balance of strength, machinability, and cost-effectiveness, making it ideal for producing high-precision components.
Important Considerations, Selection Criteria, and Further Insights
| Feature/Property | 1.0718 Steel | AISI 1212 | AISI 1045 | Brief Pro/Con or Trade-off Note |
|---|---|---|---|---|
| Key Mechanical Property | Good strength | Excellent machinability | Higher strength | 1.0718 is more cost-effective |
| Key Corrosion Aspect | Fair resistance | Good resistance | Moderate resistance | 1.0718 is less corrosion-resistant |
| Weldability | Moderate | Good | Fair | 1.0718 requires more care in welding |
| Machinability | Good | Excellent | Moderate | 1.0718 is easier to machine than 1045 |
| Formability | Good | Fair | Good | 1.0718 has better formability |
| Approx. Relative Cost | Moderate | Moderate | Low | 1.0718 is competitively priced |
| Typical Availability | Common | Common | Common | All grades are readily available |
When selecting 1.0718 Steel, considerations include its machinability, cost-effectiveness, and suitability for specific applications. While it may not offer the same corrosion resistance as stainless steels, its balance of properties makes it a valuable choice in many engineering contexts. Additionally, the environmental implications of lead content should be considered during processing and application.
