A516 Grade 70 Boiler Quality (BQ) Plate Supplier in India
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What Is A516 Grade 70 Boiler Quality Plate?
ASTM A516 Grade 70 plate is a pressure vessel quality plate made for moderate and lower temperature service. It is also known as boiler quality, or BQ plate. It is used for the boiler plant pressure parts made from plate: drums, shells, heads, and vessels such as feedwater heaters and deaerators.
The steel is killed and made to fine grain practice. Impact testing is not part of the standard requirements, so it is only carried out when you call for it on the order.
On package and smaller industrial boilers, shell courses usually fall in the 12 mm to 20 mm end of our stock, and thinner parts come from the lower end of the range. Heavier drums come from the on-order range.
A516 Grade 70 BQ Plate Specifications
| Parameter | Value |
|---|---|
| Specification | ASTM A516 Grade 70, dual certified to ASME SA-516 Grade 70 where the mill certificate covers both |
| Tensile strength | 485 to 620 MPa |
| Yield strength, minimum | 260 MPa |
| Elongation, minimum | 21 percent in 50 mm or 17 percent in 200 mm, adjusted by thickness |
| Thickness | 3 mm to 20 mm ready stock, up to 100 mm on order |
| Width and length | 1250 mm and 1500 mm wide, 5000 mm and 6300 mm long |
| Delivery condition | As-rolled from stock. Normalized above 40 mm. Normalized or stress relieved to order at any thickness |
| Certification | EN 10204:2004 Type 3.1 mill test certificate |
| Dispatch | 2 to 3 working days on stock sizes, delivery across India |
Send your plate list. We will confirm stock and price the same day.
A516 Grade 70 Boiler Quality (BQ) Plate
Chemical Composition of ASTM A516 Gr 70 Boiler Steel Plate
| Element | Plate Thickness | Heat Analysis | Product Analysis |
|---|---|---|---|
| Carbon, maximum | Up to and including 12.5 mm | 0.27% | 0.27% |
| Carbon, maximum | Over 12.5 mm to 50 mm | 0.28% | 0.28% |
| Carbon, maximum | Over 50 mm to 100 mm | 0.30% | 0.30% |
| Manganese | All thicknesses | 0.85 to 1.20% | 0.79 to 1.30% |
| Phosphorus, maximum | All thicknesses | 0.025% | 0.025% |
| Sulfur, maximum | All thicknesses | 0.025% | 0.025% |
| Silicon | All thicknesses | 0.15 to 0.40% | 0.13 to 0.45% |
The carbon limit increases with plate thickness. Manganese may also be increased when the carbon content is below its specified maximum. For every 0.01 percentage point reduction in carbon, manganese may be increased by 0.06 percentage point, up to 1.50% in the heat analysis and 1.60% in the product analysis.
ASME SA 516 Gr 70 Boiler Quality Steel Plate Mechanical Properties
The mechanical properties show the strength and ductility of A516 Grade 70 and SA-516 Grade 70 steel plate. Tensile strength, yield strength and elongation are verified by tension testing.
| Mechanical Property | Requirement |
|---|---|
| Tensile strength | 485 to 620 MPa (70 to 90 ksi) |
| Yield strength, minimum | 260 MPa (38 ksi) |
| Elongation, minimum | 21% in 50 mm or 17% in 200 mm |
Yield strength is determined by either the 0.2% offset method or the 0.5% extension-under-load method. Only the gauge length matching the test specimen applies to elongation, and the requirement is reduced for plate under 8 mm, so the certificate shows the figure for your thickness.
For an ASME order, specify SA-516 Grade 70 on the purchase order and confirm that the mill test certificate carries the ASME designation. ASTM A516 Grade 70 should not be described as ASME SA-516 Grade 70 unless the plate is certified to both specifications.
Why A516 Grade 70 Is Used for Boilers
A516 Grade 70 is usually the right choice for industrial boilers and welded pressure vessels running at moderate or lower temperatures.
- Strength. 485 to 620 MPa tensile with 260 MPa minimum yield. The design code sets the allowable stress for your vessel.
- Toughness. Killed steel made to fine grain practice, which is the basis for good notch toughness. Toughness is only verified if you order Charpy impact testing.
- Weldability. Welds and cold forms with normal carbon steel practice. Heavier sections usually need preheat.
- One grade across the vessel. Tensile and yield requirements are the same from thin plate to heavy section, so heavy shell courses and thinner parts sit on one specification.
A516 Grade 70 Boiler Steel Plate Delivery Condition
Plate 40 mm and under is normally supplied as-rolled. All our ready stock is as-rolled. You can order it normalized or stress relieved instead. Plate over 40 mm is supplied normalized.
If your specification calls for impact testing on plate up to 40 mm, that plate has to be normalized unless you state otherwise. State the test temperature, specimen orientation and acceptance criteria on the order.
If your boiler falls under IBR, tell us with your enquiry. IBR material is certified at the mill and cannot be added later to plate already in stock. An EN 10204 Type 3.1 certificate does not cover it.
Send these with your enquiry:
- Thickness, width, length and quantity
- Delivery condition, as-rolled or normalized
- Design temperature
- Any impact testing, inspection or IBR requirement
