What is the temperature range for ASME SA 516 Grade 70?
ASME SA 516 Grade 70 is a pressure vessel quality steel plate, designed for service in a temperature range of approximately −46∘C ( −50∘F ) to 538∘C ( 1000∘F ). While it provides excellent toughness for low-temperature applications (down to −46∘C), its maximum service temperature is limited by ASME code to538∘C(under Section VIII, Division 1) due to potential creep and reduction in strength.
ASME SA516 Grade 70 is the premier carbon steel grade for the fabrication of medium-to-heavy wall pressure vessels. It is a "killed" steel, meaning it is thoroughly deoxidized during manufacturing to create a dense, gas-free ingot. For fabricators, this translates to a material that is highly reliable during heavy welding and rolling operations. It is commonly supplied in the normalized condition for plates over 1.5 inches thick to ensure that the grain structure is refined and the material properties are optimized for the most demanding pressure-holding services.
Key Characteristics
Predictable Hardness: Usually stays within 160-200 HBW, facilitating easier machining.
Low Impurity Levels: Tight controls on Phosphorus and Sulfur prevent hot-cracking during welding.
Cold Forming Capacity: Despite its strength, it can be rolled into cylinders with proper equipment.
Thermal Response: Responds well to Stress Relieving (SR) or Post-Weld Heat Treatment (PWHT).
Grade Designation
"SA": The "S" indicates Section II (Materials) of the ASME Code. The "A" signifies a Ferrous Material (iron-based).
"516": This identifies the specific material specification for "Pressure Vessel Plates, Carbon Steel, for Moderate- and Lower-Temperature Service."
"Grade 70": This represents the Minimum Tensile Strength of the steel, which is 70 ksi (70,000 psi or approx. 485 MPa). It is the highest strength tier within the SA516 specification.
Comparison (vs. SA537 Class 1)
Heat Treatment: SA516 can be as-rolled; SA537 must be normalized.
Strength Floor: SA537 Class 1 has a higher yield strength (50 ksi) than SA516 Gr. 70 (38 ksi).
Alloying: SA537 has higher Manganese (1.6%) compared to SA516 (1.2%).
Application Depth: SA537 is used for even more critical, higher-stress applications than Gr. 70.
Common Applications
LNG Storage Tanks: Components used in the non-cryogenic sections of LNG terminals.
Deaerators: Vital for removing dissolved gases from boiler feed water.
Filter Housings: For high-pressure liquid and gas filtration in refineries.
Autoclaves: Large-scale pressurized vessels used in aerospace or wood treatment.
What is the elongation of ASME SA516 Grade 70?
For plates with a thickness of up to 1.5 inches (38 mm), ASME SA516 Grade 70 typically exhibits an elongation of 20% in 8 inches (200 mm). This high elongation value indicates the material's good ductility, allowing it to stretch without breaking under tension. The elongation properties are important for ensuring that pressure vessels made from this material can withstand high-stress conditions without failure.
What are the equivalents of ASME SA516 Grade 70?
ASME SA516 Grade 70 is equivalent to ASTM A516 Grade 70. Other international equivalents include EN 10028-3 P355GH, DIN 17155 19Mn6, and JIS G3115 SPV355. These materials share similar chemical compositions and mechanical properties, though specific testing standards and requirements may differ. Always check local regulations or consult with engineering professionals to ensure material compatibility in your application.
What is ASME SA516 Grade 70?
ASME SA516 Grade 70 is a carbon steel used for manufacturing pressure vessels and boilers. It is part of the ASME Boiler and Pressure Vessel Code (BPVC) and is widely utilized in industries such as power generation, petrochemical, and chemical processing. Known for its high strength and excellent weldability, it can withstand elevated temperatures and pressures, making it ideal for high-stress applications.
Mechanical Properties
|
Grade |
Yield strength |
Tensile strength |
Elongation in 2" 1) |
Elongation in 8" 1) |
|---|---|---|---|---|
|
70 |
38 |
70 - 90 |
21 |
17 |
Chemical Composition
|
C |
Mn 1) |
P 2) |
S 2) |
Si |
|---|---|---|---|---|
|
0.25 |
0.85 - 1.20 |
0.020 |
0.010 |
0.40 |
1. What is the maximum thickness for ASME SA516 Grade 70?
ASME SA516 Grade 70 plates are commonly available in thicknesses ranging from 3/16 inches (4.76 mm) to 4 inches (102 mm). Thicker plates may be used for specialized applications, but the material's ability to withstand pressure increases with thickness. For very thick plates, additional heat treatment and post-weld procedures are often required to ensure the desired mechanical properties are maintained.
2. What are the welding considerations for ASME SA516 Grade 70?
Welding ASME SA516 Grade 70 requires careful control of heat input to prevent cracking and distortion. Preheating and post-weld heat treatment (PWHT) are commonly recommended for thicker sections to reduce thermal stresses. Proper selection of filler metals and welding techniques, such as Shielded Metal Arc Welding (SMAW) or Gas Tungsten Arc Welding (GTAW), is important to ensure strong, reliable welds without compromising material properties.
3. What is the tensile strength of ASME SA516 Grade 70?
The tensile strength of ASME SA516 Grade 70 ranges from 70 ksi to 90 ksi (483–620 MPa). This provides the material with the ability to withstand high internal pressure and mechanical stress without failure. This tensile strength makes it a reliable material for use in pressure vessels, boilers, and other high-pressure systems, ensuring long-term structural integrity even in demanding applications.
4. What is the sulfur content in ASME SA516 Grade 70?
The sulfur content in ASME SA516 Grade 70 is limited to a maximum of 0.035%. Low sulfur content is critical in preventing the formation of sulfide inclusions, which can weaken the material and make it more prone to cracking, especially during welding. This helps ensure the material's strength and durability, especially in high-pressure applications.
5. What is the chemical composition of ASME SA516 Grade 70?
The chemical composition of ASME SA516 Grade 70 typically includes:,Carbon (C): 0.19–0.24%,Manganese (Mn): 0.60–1.35%,Phosphorus (P): ≤0.035%,Sulfur (S): ≤0.035%,Silicon (Si): 0.15–0.40%,These elements contribute to the material's high tensile strength, toughness, and resistance to thermal degradation, making it suitable for high-temperature pressure vessel applications.
6. What is the Brinell hardness for ASME SA516 Grade 70?
The Brinell hardness for ASME SA516 Grade 70 typically ranges from 130 to 160 HB. This hardness ensures the material maintains its strength and resistance to wear while still allowing for good weldability. The hardness level is optimized to balance strength, ductility, and resistance to deformation, making it suitable for high-pressure applications in demanding industries like oil and gas.
7. What are the inspection requirements for ASME SA516 Grade 70?
The inspection requirements for ASME SA516 Grade 70 include visual inspection, ultrasonic testing (UT), and sometimes magnetic particle or dye penetrant testing for surface defects. Mechanical tests such as tensile, impact, and hardness tests are carried out to ensure the material meets the required mechanical properties. Certification and inspection are necessary to ensure the material's suitability for pressure vessels and other critical applications.
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