ASTM A203 Grade D and Grade E are nickel-alloy steel plates for welded pressure vessels, differing mainly in nickel content and mechanical properties: Grade D has about 2.25% nickel, offering good low-temp toughness, while Grade E has around 3.25% nickel, providing higher strength for even colder service. Both are typically normalized and specified for low-temperature impact resistance, crucial for industries like oil, gas, and chemical processing.
Chemical Composition
A203 Grade DChemical Composition | |||||
Grade | The Element Max (%) | ||||
C | Si | Mn | P | S | |
A203 Grade D | 0.17 | 0.13-0.45 | 0.70-0.80 | 0.035 | 0.035 |
A203 Grade EChemical Composition | |||||
Grade | The Element Max (%) | ||||
C | Si | Mn | P | S | |
A203 Grade E | 0.20 | 0.13-0.45 | 0.70-0.80 | 0.035 | 0.035 |
Mechanical Property
Mechanical Property of A203 Grade D steel plate | A203 Grade D |
Tensile strength, kis [MPa] | 65-85 [450-585] |
Yield strength, min, kis [MPa] | 37 [255] |
Elongation in 8 in. [200 mm], min, % | 19 |
Elongation in 2 in. [50 mm], min, % | 23 |
Mechanical Property of A203 Grade E steel plate | A203 Grade E |
Tensile strength, kis [MPa] | 70-90 [485-620] |
Yield strength, min, kis [MPa] | 40 [275] |
Elongation in 8 in. [200 mm], min, % | 17 |
Elongation in 2 in. [50 mm], min, % | 21 |
ASTM A203 Grade D
Nickel Content: Approximately 2.25%.
Usage: Primarily for welded pressure vessels and boilers, especially where low-temperature service is required.
Properties: Good tensile strength and impact toughness at low temperatures.
ASTM A203 Grade E
Nickel Content: Approximately 3.25%.
Usage: Similar to Grade D, used in pressure vessels and boilers but designed for even lower operating temperatures due to its higher nickel content.
Properties: Higher tensile strength and yield strength than Grade D, with enhanced low-temperature performance, sometimes even requiring quench and temper heat treatment for enhanced strength.
Key Differences Summarized
Nickel: D has ~2.25% Ni; E has ~3.25% Ni.
Strength: Grade E offers higher minimum tensile and yield strength than Grade D.
Application: Both for low-temp pressure vessels, but E is for colder conditions than D.
