Gangsteel produces and exports ASME SA203 Grade F nickel alloy steel plate for welded pressure vessels. Grade F is the quenched and tempered, highest-strength grade of the 3.50% nickel family in the ASME SA203 Steel Plates range, with a minimum yield strength of 55 ksi [380 MPa] for plates 2 in. [50 mm] and under.
Grade F has the same chemistry table as SA203 Grade E and the same nominal nickel as SA203 Grade D, but it is the only SA203 grade that must be quenched and tempered, and its strength drops above 2 in. [50 mm]. Grade F plates are impact tested under Supplementary Requirement S5 of SA-20, so the Charpy test temperature and energy for the service temperature must be stated on the order.
Grade Designation
- SA – ASME Boiler and Pressure Vessel Code material specification (Section II, Part A)
- 203 – SA-203/SA-203M, pressure vessel plates, alloy steel, nickel
- Grade F – 3.50% nominal nickel, quenched and tempered, 55 ksi [380 MPa] minimum yield up to 2 in. [50 mm] and 50 ksi [345 MPa] above
ASTM counterpart: ASTM A203 Grade F. Common writings include SA203GR.F, SA203 Gr.F and SA-203 Grade F.
Key Advantages of SA203 Grade F Steel Plate
- Highest strength in SA-203, above Grades D and E
- 3.50% nominal nickel for low-temperature service
- Quenched and tempered delivery, with tempering at not less than 1100 °F [595 °C]
- Charpy impact testing to SA-20 Supplementary Requirement S5
- Intended for welded pressure vessels
Chemical Composition (Heat Analysis, Maximum %)
| Plate thickness | C | Mn | P | S | Si | Ni |
|---|---|---|---|---|---|---|
| ≤ 2 in. [50 mm] | 0.20 | 0.70 | 0.025 | 0.025 | 0.15 – 0.40 | 3.25 – 3.75 |
| > 2 in. to 4 in. [50 – 100 mm] incl. | 0.23 | 0.80 | 0.025 | 0.025 | 0.15 – 0.40 | 3.25 – 3.75 |
Product analysis: Mn 0.78 max (≤ 50 mm) and 0.88 max (> 50 mm), Si 0.13 – 0.45, Ni 3.18 – 3.82. P and S maxima apply to both heat and product analysis. Si and Ni are ranges, not maxima.
Note: Grades E and F share one chemistry table. The table gives carbon maxima only up to 4 in. [100 mm]; there is no > 100 mm carbon row for the 3.50% nickel grades, so do not copy the Grade A or Grade B > 100 mm value. The actual heat analysis is shown on the mill certificate. Confirm all limits against the SA-203 edition named on your order.
Mechanical Properties
| Plate thickness | Tensile Strength ksi [MPa] | Yield Strength min ksi [MPa] | Elongation in 2 in. [50 mm] min % |
|---|---|---|---|
| ≤ 2 in. [50 mm] | 80 – 100 [550 – 690] | 55 [380] | 20 |
| > 2 in. [50 mm] | 75 – 95 [515 – 655] | 50 [345] | 20 |
Note: Grade F is the only SA-203 grade whose tensile requirements change with thickness, so design to the line for the ordered thickness. No elongation in 8 in. [200 mm] is specified for Grade F. Elongation adjustments follow SA-20; for plates 3/4 in. [20 mm] and under tested on the 1½ in. [40 mm] wide specimen, elongation in 2 in. [50 mm] is not less than 23%. Charpy V-notch testing is to SA-20 Supplementary Requirement S5; temperature and energy are set on the order. Guaranteed values must be confirmed on the mill certificate for the ordered thickness and edition.
SA203 Grade Comparison
| Grade | Nominal Ni % | C max % (≤ 50 mm / 50 – 100 mm / > 100 mm) | Yield min ksi [MPa] | Tensile ksi [MPa] | Elongation in 2 in. [50 mm] min % | Heat treatment |
|---|---|---|---|---|---|---|
| SA203 Grade A | 2.25 | 0.17 / 0.20 / 0.23 | 37 [255] | 65 – 85 [450 – 585] | 23 | Normalized |
| SA203 Grade B | 2.25 | 0.21 / 0.24 / 0.25 | 40 [275] | 70 – 90 [485 – 620] | 21 | Normalized |
| SA203 Grade D | 3.50 | 0.17 / 0.20 / – | 37 [255] | 65 – 85 [450 – 585] | 23 | Normalized |
| SA203 Grade E | 3.50 | 0.20 / 0.23 / – | 40 [275] | 70 – 90 [485 – 620] | 21 | Normalized |
| SA203 Grade F | 3.50 | 0.20 / 0.23 / – | 55 [380] ≤ 50 mm; 50 [345] > 50 mm | 80 – 100 [550 – 690] ≤ 50 mm; 75 – 95 [515 – 655] > 50 mm | 20 | Quenched and tempered |
Note: “–” means the chemistry table gives no carbon maximum above 100 mm for the 3.50% nickel grades. Mn (0.70 / 0.80 heat max), P 0.025 max, S 0.025 max and Si 0.15 – 0.40 are the same for all five grades. Grades A, B, D and E that receive purchaser-approved accelerated cooling plus tempering must meet a Charpy V-notch value of 20 ft·lbf [27 J] at an agreed temperature; Grade F is impact tested to SA-20 Supplementary Requirement S5. Same nickel or same strength does not make two grades interchangeable.
Available Dimensions
- Thickness: to enquiry. SA-203 sets no fixed maximum; thickness is limited by the ability of the composition to meet the mechanical requirements, and the chemistry table covers carbon up to 4 in. [100 mm]
- Width and length: to enquiry
- Tolerances: SA-20/SA-20M unless otherwise agreed
- Delivery condition: Quenched (water) and tempered at not less than 1100 °F [595 °C] for at least ½ h
Main Applications
- Welded pressure vessels for low-temperature service that need higher strength than Grade E
- Low-temperature process vessels, separators and drums
- Thinner-wall shells and heads where the design uses Grade F strength
- Petrochemical and gas processing equipment that names 3.50% nickel quenched and tempered plate
Equivalent Grades of SA203 Grade F
| Standard | Grade | Steel Number | Remarks |
|---|---|---|---|
| ASTM A203/A203M | A203 Grade F | – | Companion ASTM grade. Related, but an ASTM certificate is not automatically SA-203 or ASME Code acceptance, and the reverse is also not automatic |
| ASME SA-203 | SA203 Grade E | – | Same chemistry, but normalized and lower strength; not equivalent |
| ASME SA-203 | SA203 Grade D | – | Same 3.50% nickel, normalized, much lower strength; not equivalent |
| JIS G3127 | SL3N440 | – | Approximate: Japanese quenched and tempered 3.5% nickel plate; 440 MPa minimum yield and different limits |
| EN 10028-4 | 12Ni14 | 1.5637 | Approximate: European 3.5% nickel pressure vessel steel; heat treatment, strength and test rules differ |
| GB/T 713.4 (China) | 08Ni3DR | – | Approximate: Chinese 3.5% nickel low-temperature vessel plate; not a quenched and tempered Grade F match |
Equivalents are for reference only. A grade from another standard, or another SA203 grade, is not a direct substitute unless the designer or the project specification accepts it. Check chemistry, strength, heat treatment, impact testing and the named acceptance standard before approving any alternative.
Related Products
Other grades in the ASME SA203 Steel Plates range and related pages:
- ASME SA203 Steel Plates (family page)
- ASME SA203 Grade A nickel alloy steel plate
- ASME SA203 Grade B nickel alloy steel plate
- ASME SA203 Grade D nickel alloy steel plate
- ASME SA203 Grade E nickel alloy steel plate
- ASTM A203 Grade F alloy steel plate
- ASME SA537 steel plates
- Pressure vessel and boiler steel plate
Frequently Asked Questions (FAQ)
What is the difference between ASME SA203 Grade E and ASME SA203 Grade F?
ASME SA203 Grade E (ASME SA203 GR.E) and ASME SA203 Grade F (ASME SA203 GR.F) share the same chemistry table. Grade E is normalized with 40 ksi [275 MPa] minimum yield. ASME SA203 GR.F is quenched and tempered with 55 ksi [380 MPa] minimum yield up to 2 in. [50 mm] and 50 ksi [345 MPa] above. Normalized ASME SA203 Grade E is not a Grade F substitute, and the reverse needs the purchaser’s approval.
Why does ASME SA203 Grade F strength change with thickness?
SA-203 gives ASME SA203 Grade F (ASME SA203 GR.F) two tensile lines: 80 – 100 ksi [550 – 690 MPa] with 55 ksi [380 MPa] yield up to 2 in. [50 mm], and 75 – 95 ksi [515 – 655 MPa] with 50 ksi [345 MPa] yield above. Use the line for the actual plate thickness in the design.
What heat treatment does ASME SA203 Grade F (ASME SA203 GR.F) need?
All ASME SA203 Grade F plates are heated into the austenitic range, quenched in water and tempered at not less than 1100 °F [595 °C] for not less than ½ h. Normalizing alone does not meet ASME SA203 GR.F.
Is impact testing required for ASME SA203 Grade F steel plate?
Yes. ASME SA203 Grade F (ASME SA203 GR.F) plates are impact tested in accordance with Supplementary Requirement S5 of SA-20. State the test temperature, energy and orientation that your design needs on the order.
Is ASME SA203 Grade F the same as ASTM A203 Grade F?
ASME SA203 Grade F (ASME SA203 GR.F) and ASTM A203 Grade F (ASTM A203 GR.F) are companion designations with the same grade name. Check the editions named on the order. An ASTM A203 Grade F certificate is not by itself SA-203 or ASME Code acceptance; ask for dual certification if both are required.
What is the nickel content of ASME SA203 Grade F?
Nominal nickel in ASME SA203 Grade F (ASME SA203 GR.F) is 3.50%. The heat analysis range is 3.25 – 3.75% and the product analysis range is 3.18 – 3.82%, the same as ASME SA203 Grade D and ASME SA203 Grade E.
What information should I give when asking for an ASME SA203 Grade F quotation?
Give the grade (ASME SA203 Grade F, also written ASME SA203 GR.F), the SA-203 edition and any Code year the job requires, SA-203 or SA-203M units, thickness × width × length, quantity, impact test temperature and energy, other supplementary tests and the inspection document you need.
For a quotation or technical data for ASME SA203 Grade F steel plate, please contact Gangsteel.