SA203GrB Nickel Alloy Steel Plate for Pressure Vessels - Chemical Composition & Manufacturing Process
Overview
SA203GrB belongs to the ASME SA203 series of low-nickel alloy steel plates for pressure vessel applications.
The series includes grades A, B, D, E, and F. Among them, grades D, E, and F have a nominal nickel content of about 3.5%, commonly referred to as "3.5Ni steel".
These grades offer excellent impact toughness and stable mechanical properties in low-temperature service, suitable for operating conditions from -70°C to -101°C (up to -107°C in the quenched and tempered condition).
Standards
Manufactured in accordance with ASME SA203/SA203M, equivalent to ASTM A203/A203M-12.
Delivery Condition
Typically supplied in normalized or normalized + tempered condition.
Chemical Composition
| Thickness Range | C | Si | Mn | P ≤ | S ≤ | Ni |
|---|---|---|---|---|---|---|
| ≤ 50 mm | ≤ 0.21 | 0.15–0.40 | ≤ 0.70 | 0.025 | 0.025 | 2.10–2.50 |
| > 50 to ≤ 100 mm | ≤ 0.24 | 0.15–0.40 | ≤ 0.80 | 0.025 | 0.025 | 2.10–2.50 |
| > 100 mm | ≤ 0.25 | 0.15–0.40 | ≤ 0.80 | 0.025 | 0.025 | 2.10–2.50 |
SA203 series is a fully killed steel, designed to ensure low-temperature impact resistance and good weldability.
Mechanical Properties
| Item | Value Range |
|---|---|
| Tensile Strength (MPa) | 485–620 |
| Yield Strength (MPa) | ≥ 275 |
| Elongation (L₀ = 200 mm) | ≥ 17 % |
| Elongation (L₀ = 50 mm) | ≥ 21 % |
The material provides excellent low-temperature toughness and a favorable yield-to-tensile ratio, meeting the safety requirements of pressure vessel design.
Available Sizes
Thickness: 8–150mm
Width: 1600–4020mm
Length: 6000–18800mm
Applications
SA203 Gr.B is mainly used for Ni-alloy steel plates in welded pressure vessels, particularly in low-temperature and high-pressure environments. Typical applications include:
- Pressure Vessels: Petrochemical equipment, power station boilers (suitable for medium and low temperature service)
- General Industry: Low-temperature storage tanks, reactor shells (material selection must match the design temperature)
Choose Gnee Steel - Your Trusted Supplier
With years of experience in manufacturing and exporting SA203GrB and other pressure vessel steel plates, Gnee Steel ensures stable quality, complete size range, and customized production according to your requirements. Our products comply with international standards and are backed by competitive pricing and fast delivery.
📩 Contact us today to get the latest SA203GrB quotation and technical support!
Keywords: alloy steel plate, nickel alloy steel, pressure vessel steel plate, load-bearing components, vessel steel