Boiler & Pressure Vessel Plates
ASME SA516 Grade 70 / Q345R Boiler & Pressure Vessel Steel Plate
Product Overview & Manufacturing Standard
This plate is supplied dual certified to ASME SA516/SA516M Grade 485 (the metric designation of SA516 Grade 70) and GB 713-2014 Q345R. It is a fine-grain, normalized carbon steel plate engineered for the shells, heads and nozzles of boilers, pressure vessels, storage tanks and heat exchangers.
Delivery condition: Normalized (N) or Normalized + Post-Weld Heat Treated (N + PWHT). Thickness range 6 mm – 200 mm, width up to 3,200 mm, length up to 12,000 mm. An ultra-low sulphur variant (S ≤ 0.002 %) is available for wet H2S service where hydrogen-induced cracking (HIC) resistance is required.
Equivalent Grades
| Standard | Equivalent Grade | Minimum Yield | Tensile Range | Notes |
|---|---|---|---|---|
| ASME SA516/SA516M | Grade 485 (= Grade 70) | 260 MPa | 485 – 620 MPa | Metric designation Gr.485 |
| GB 713-2014 (China) | Q345R | 345 MPa (≤ 16 mm) | 510 – 640 MPa | Boiler & pressure vessel plate |
| EN 10028-2 (Europe) | P295GH / P355GH | 295 / 355 MPa | 440 – 570 / 510 – 650 MPa | Elevated temperature service |
| JIS G3118 (Japan) | SGV410 | 245 MPa | 410 – 550 MPa | Pressure vessel steel |
| ISO 9328-2 | P295GH | 295 MPa | 440 – 570 MPa | Pressure purposes |
Chemical Composition (Ladle Analysis, %)
| Element | SA516 Gr.70 / SA516M Gr.485 | Q345R (GB 713-2014) | Ultra-low S / HIC Grade |
|---|---|---|---|
| C | ≤ 0.28 (≤ 0.30 for > 50 mm) | ≤ 0.20 | ≤ 0.20 |
| Si | 0.15 – 0.40 | ≤ 0.55 | 0.15 – 0.40 |
| Mn | 0.85 – 1.20 | 1.20 – 1.60 | 1.20 – 1.60 |
| P | ≤ 0.035 | ≤ 0.025 | ≤ 0.015 |
| S | ≤ 0.035 | ≤ 0.010 | ≤ 0.002 |
| Al (total) min | 0.020 | 0.020 | 0.020 |
| Cu / Ni / Cr / Mo | ≤ 0.35 / 0.30 / 0.30 / 0.08 | Residual limits per GB 713 | ≤ 0.25 / 0.30 / 0.30 / 0.08 |
| CEV (typ. order requirement) | ≤ 0.45 | ≤ 0.45 | ≤ 0.43 |
The ultra-low sulphur route (desulphurised and calcium-treated, S ≤ 0.002 %) delivers excellent resistance to hydrogen-induced cracking. Plates for wet H2S service are verified by NACE TM0284 HIC testing (CLR ≤ 15 %, CTR ≤ 5 %, CSR ≤ 2 %) and hardness ≤ 22 HRC in the weld and HAZ.
Mechanical Properties
| Grade | Thickness | Yield ReH | Tensile Rm | Elongation A | Impact (Charpy V) |
|---|---|---|---|---|---|
| SA516 Gr.70 (≤ 50 mm) | 6 – 50 mm | ≥ 260 MPa | 485 – 620 MPa | ≥ 21 % | Optional, per ASME SA20 / order |
| SA516 Gr.70 (50 – 200 mm) | 50 – 200 mm | ≥ 260 MPa | 485 – 620 MPa | ≥ 19 % | Optional, per ASME SA20 / order |
| Q345R (≤ 16 mm) | 3 – 16 mm | ≥ 345 MPa | 510 – 640 MPa | ≥ 21 % | ≥ 41 J at 0°C |
| Q345R (16 – 36 mm) | 16 – 36 mm | ≥ 325 MPa | 500 – 630 MPa | ≥ 21 % | ≥ 41 J at 0°C |
| Q345R (36 – 60 mm) | 36 – 60 mm | ≥ 315 MPa | 490 – 620 MPa | ≥ 21 % | ≥ 41 J at 0°C |
| Q345R (60 – 100 mm) | 60 – 100 mm | ≥ 305 MPa | 490 – 620 MPa | ≥ 21 % | ≥ 41 J at 0°C |
Elevated-temperature design data, creep stress values and low-temperature impact data are available for each heat on request. Hardness is typically 150 – 190 HBW in the normalized condition.
Post-Weld Heat Treatment (PWHT) & Ultrasonic Testing
| Process | Specification / Control |
|---|---|
| Normalizing | 900°C – 940°C, still air cooling, fine grain size ≥ ASTM 6 |
| PWHT temperature | 595°C – 650°C (stress relief), furnace charged below 400°C |
| Heating / cooling rate | ≤ 55°C per hour above 400°C, uniform soak, controlled cooling to 400°C then air cool |
| Holding time | 1 hour per 25 mm of thickness, minimum 1 hour |
| Temperature control | Calibrated thermocouples, full chart record issued with the certificate |
| Ultrasonic testing | ASME SA435 straight-beam 100 % or ASME SA578 straight + angle beam, Level I / II / III per order |
| Surface examination | Edge MT / PT after shearing or flame cutting where specified |
| Coupon tests | Full ASME SA20 mechanical test plate, plus simulation of PWHT for weld qualification |
Applications & Fabrication Notes
- Pressure vessel shells, heads, skirts and nozzles; boiler drums and headers; storage tanks and heat exchanger bodies
- Wet H2S service in refining and petrochemical plants (HIC-resistant option)
- Welding with E7018 / E7015 electrodes or equivalent submerged-arc combinations; preheat 100°C when thickness exceeds 32 mm
- Hydrogen-controlled consumables and interpass temperature below 250°C to protect the HAZ toughness
- No flame straightening above the PWHT temperature; re-test if repairs exceed the limits of the applicable code
Request ASME SA516 Grade 70 / Q345R Boiler & Pressure Vessel Steel Plate Quotation & Mill Certificate
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