SA612 is killed carbon-manganese-silicon steel plate made for welded pressure vessels. Its fine grain makes it suitable for use in moderate and lower temperature service where impact resistance is important.
More Details About SA612
Advantages
SA612 is a high value pressure vessel quality steel plate. PVQ steel plates are specifically certified to contain liquids and gasses under ambient conditions. This grade provides good notch toughness and can tolerate moderate to lower temperatures.
Industries
The grade is fully killed, or deoxidized to meet mechanical standards required by oil, gas, and petrochemical industries for use in fusion welded industrial boilers and pressure vessels.
Applications
The grade is best for use in pressure vessels and industrial boilers. It is also ideal for other applications with exposure to moderate and low temperature conditions, and where high strength is required.
Machining
It has good machinability.
Welding
It has excellent weldability.
Heat Treatment
It is heat treatable.
SA612 Chemical Composition (ASTM A612/A612M)
| Element | Content Range (%) |
|---|---|
| Carbon (C) | ≤0.25 |
| Manganese (Mn) | 1.00–1.50 |
| Silicon (Si) | 0.15–0.50 |
| Phosphorus (P) | ≤0.025 |
| Sulfur (S) | ≤0.025 |
| Copper (Cu) | ≤0.20 |
| Nickel (Ni) | ≤0.30 |
| Chromium (Cr) | ≤0.30 |
| Molybdenum (Mo) | ≤0.15 |
| Vanadium (V) | ≤0.08 |
| Carbon Equivalent (CE) | ≤0.48 |
SA612 Mechanical Properties (ASTM A612/A612M)
| Property | Test Condition | Minimum Value |
|---|---|---|
| Yield Strength (YS) | Room Temperature (20°C) | 345 MPa (50 ksi) |
| Tensile Strength (TS) | Room Temperature (20°C) | 570–725 MPa (83–105 ksi) |
| Elongation (A) | Room Temperature (20°C) | 22% |
| Impact Toughness (Charpy V-Notch) | -40°C (-40°F) | 27 J (20 ft-lb) |
| Impact Toughness (Charpy V-Notch) | -45°C (-49°F) | 20 J (15 ft-lb) |
| Hardness (Brinell) | Room Temperature (20°C) | ≤207 HB |
Additional Mechanical Performance Highlights:
Low-Temperature Stability: Maintains ductility and toughness at temperatures as low as -45°C, outperforming standard carbon steels like SA516 Gr.70.
Weldability: Low carbon equivalent (≤0.48%) allows for multi-pass welding without preheating (for thicknesses ≤150mm), reducing fabrication costs.
Creep Resistance: Retains strength at sustained high temperatures (up to 425°C), making it suitable for nuclear power plant components and high-temperature pressure vessels.
What limits the maximum thickness of SA612?
This steel plate, and other PVQ carbon plates, have a maximum thickness that is limited by the ability of the steel to meet mechanical property specifications set by the ASTM.
What is the tensile strength of SA612?
The ultimate tensile strength for this high carbon steel falls between 560 – 695 MPa, or 81,200 – 101,000 psi.
Why SA612 Shines in LNG Tank Applications
1. Superior Low-Temperature Performance
Maintains high ductility and impact resistance at temperatures as low as -45°C, matching LNG storage conditions
Prevents catastrophic brittle failure that could occur with conventional steels at cryogenic temperatures
Outperforms common alternatives like SA516 Gr.70 with 40% higher impact toughness at low temperatures
2. Optimal Strength-to-Weight Ratio
High strength allows for thinner tank walls while maintaining structural integrity
Reduces overall weight of LNG storage facilities, especially important for offshore applications
Enables cost-efficient construction without compromising safety
3. Welding Efficiency
Low carbon equivalent (≤0.48%) permits welding without preheating for thicknesses up to 150mm
Minimizes thermal stress and distortion during fabrication, reducing costly rework
Facilitates precise, high-quality welds critical for leak prevention in LNG tanks
4. Cost-Effectiveness
Offers comparable performance to more expensive alloys (e.g., stainless steels) at a lower cost
Balances initial material cost with long-term reliability in LNG service
Why SA612 Excels in Nuclear Power Plants
1. Structural Reliability Under Extreme Conditions
Maintains dimensional stability in high-pressure environments (up to 21 MPa)
Resists creep deformation under sustained high temperatures (≤425°C) in nuclear systems
Provides consistent performance throughout the design life of nuclear components
2. Applications in Key Nuclear Components
Reactor Pressure Vessels: Used in secondary containment structures requiring strength and leak resistance
Steam Generators: Withstands thermal cycling between high-pressure steam and feedwater
Nuclear : Maintains pressure stability in pressurized water reactors
Heat Exchangers: Facilitates efficient energy transfer while resisting corrosion
3. Safety-Critical Performance
Excellent notch toughness prevents crack propagation in reactor components
Low sulfur and phosphorus content (≤0.025%) enhances resistance to stress corrosion cracking
Fine-grained microstructure improves resistance to radiation damage
GNEE Steel also supplies a variety of boilers and pressure vessel steel plates, such as A204 Grade B,A515 Grade 70,A537 Class 1,SA387 Grade 11 Class 1,P265GH,S537 Class 2,P355Q,P275N,P355N,P690Q,Q345R, etc. If you want to know more about other types of steel plates, you can call the consultation hotline at +8615824687445 or send an email to info@gneesteels.com. You are welcome to consult us, and we are very willing to answer your questions.
FAQ
What is SA 612 material?
carbon-manganese-silicon steel plate
SA612 is killed carbon-manganese-silicon steel plate made for welded pressure vessels. Its fine grain makes it suitable for use in moderate and lower temperature service where impact resistance is important.
What is the composition of ASTM A612?
ASTM A612 steel plate is a high-strength low-alloy (HSLA) steel plate designed for welded pressure vessels. It has a nominal composition of carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, and copper.
What is A612 steel?
ASTM A612 specification is the Standard Specification for Pressure Vessel Plates, Carbon Steel, High Strength, for Moderate and Lower Temperature Service. ASTM A612 encompasses carbon-manganese-silicon steel plates intended for use in welded pressure vessels for moderate and low temperature service.
Are SA612 and A612 Steel Plates the Same Product? What Are the Core Differences?
They are the same type of steel plate. ASTM A612 is the material standard, while ASME SA612 is the designation assigned after ASTM A612 was incorporated into the ASME Boiler & Pressure Vessel Code, specifically for the fabrication of pressure-bearing equipment.
What Are the Executive Standards for SA612/A612 Steel Plates? Are There Any Differences Between the ASTM and ASME Versions?
The executive standards are ASTM A612/A612M and ASME SA612. There are no substantial differences in chemical composition and mechanical properties between the two versions; the only variance lies in their applicable code systems.
What Are the Equivalent Grades of SA612/A612 in Chinese and European Standards? Can They Be Used as Direct Substitutes?
Common approximate equivalent grades include EN P355GH, DIN 1.0473, and GB Q345R. However, they cannot be used as direct equivalents. Their suitability must be confirmed in accordance with design specifications and approval requirements.
What Are the Yield Strength and Tensile Strength of SA612/A612? Do They Vary with Different Thicknesses?
The minimum yield strength of SA612 is approximately 260 MPa, and its tensile strength ranges from 485–620 MPa. As the thickness increases, the allowable minimum yield strength may decrease slightly.
What Are the Low-Temperature Impact Energy Requirements for SA612/A612? Are the Requirements at -40℃ and -45℃ Consistent?
Standards typically require impact testing at -40℃, while testing at -45℃ is not mandatory. If a project specifies -45℃ testing, additional impact tests must be conducted and clearly defined in the technical agreement.
What Are the Minimum and Maximum Service Temperatures for SA612/A612?
The recommended minimum service temperature is approximately -40℃, and the maximum operating temperature is generally around 400℃, depending on the design specifications and service medium.
What Is the Carbon Equivalent of ASME SA612? Is Preheating Required for Welding?
The carbon equivalent is usually around 0.42–0.45. Preheating at 50–120℃ is recommended for welding medium and thick plates. Commonly used welding materials include low-hydrogen electrodes such as E7018 and E7016.
What Is the Routine Thickness Range of SA612/A612, and What Is the Maximum Customizable Thickness?
The routine thickness range is 6–100 mm. Some steel mills can provide customized thicknesses up to 150 mm, subject to confirmation of their rolling and heat treatment capabilities.
What Are the Common Delivery Conditions for SA612/A612?
Common delivery conditions include As-Rolled (AR), Normalized (N), and Normalized + Tempered (N+T), with the normalized condition being the most widely used.
What Is the Machinability of SA612? Is It Prone to Cracking?
SA612 exhibits excellent cutting and bending performance. When processed with proper techniques and preheating, it is not prone to cracking.
Which Is More Suitable for Low-Temperature Applications: SA612 or SA516 Gr.70?
SA612 delivers more stable comprehensive performance in thick plate and high-stress working conditions, whereas SA516 Gr.70 offers better cost-effectiveness in conventional operating conditions.
Can Q345R Be Used as a Substitute for SA612?
Q345R can be used as a substitute in some working conditions for non-ASME projects. However, substitution is not recommended for export projects or scenarios where SA612 is explicitly required by specifications.
What Are the Differences Between SA612 and SA537 Cl.2?
SA537 Cl.2 boasts higher strength and low-temperature performance but comes with a significantly higher cost than SA612. It is suitable for more severe operating conditions.
Is SA612 Vessel Plate Suitable for LNG Storage Tanks?
SA612 is not recommended for primary LNG storage tanks operating at -162℃, but it can be used in LNG auxiliary systems or medium-to-low temperature vessels.
What Is the Hydrogen-Induced Cracking (HIC) Resistance of SA612 Steel Plates?
Standard SA612 does not mandate HIC resistance requirements. For applications involving sulfur-containing media, customized low-sulfur and low-phosphorus SA612 plates must be used, accompanied by HIC testing.
| Other steel plate by GNEE | ||||
| Name | Material | Specification (mm) | Tons | Remark |
| Clad steel plate | P265GH+410,S355JR+410,A516Gr70+316, A537CL1+304L,Q235B+304L,Q345B+304, A516Gr70(NACE)+410,A537CL1+904L, A537CL1+316L,A516Gr70+304L,A537CL1+304 ,A516Gr70+410,A516Gr70+904L |
2-300mm(Based plate),1-50mm(Composited plate) | / | UT, AR, TMCP.Normalized, Quenched and Tempered,Z Direction Test, Charpy V-Notch impact TestThe Third Party Test , Coated or Shot Blasting and Painting. |
| Low Alloy | Q345A, Q345B, Q345C, Q345D, Q345E, Q390, Q420, Q460C, ST52-3, S355J2+N, SS400, SA302GrC, S275NL, 35CrMo | 6 - 350 | 5788.56 | Normalizing, tempered ,controlled rolling, hot rolling , Hot rolling,1st inspection, 2nd inspection, 3rd inspection |
| Pressure Vessel Plate | Q245R, Q345R, Q370R, 16MnDR, 09MnNiDR, 15CrMoR, 14Cr1MoR, 12Cr2Mo1R, SA516Gr60, SA516Gr70, SA516Gr485, SA285, SA387Gr11, SA387Gr12, SA387Gr22, P265,P295,P355GH,Q245R(R-HIC),Q345R(R-HIC) | 3 - 300 | 8650 | Normalizing, tempered ,controlled rolling, hot rolling , Hot rolling,1st inspection, 2nd inspection, 3rd inspection |
| High-Strength Plate | WH785D/E,Q960D/E, Q890D/E,WH60D/E,WH70B,Q550D,Q590D,Q690D/E | 8 - 120 | 3086.352 | Quenched and tempered |
| Wear-Resistant Plate | NM360, NM400, NM450, NM500 | 6 - 150 | 3866.297 | Quenched and tempered |
| Bridge Plate | Q235qC, Q345qC, Q370qC, Q420qC, Q345qDNH, Q370qDNH, A709 - 50F - 2, A709 - 50T - 2 | 8 - 200 | 2853.621 | Hot rolling, normalized ,hot rolling controlled rolling, quenched and tempered + toughness and brittleness |
