What Is ASTM A333 Low Temperature Steel Pipe？
ASTM A333 covers seamless and welded carbon and alloy steel pipe for use in cryogenic environments. During the manufacturing process of these steel pipes, whether using seamless or welding processes, there is no need to add filler metal during the welding process. At the same time, all these steel pipes require microstructural control processing. The standard covers multiple ferritic steel grades, including Grade 1, Grade 3, Grade 4, Grade 6, Grade 7, Grade 8, Grade 9, Grade 10 and Grade 11. Of these grades, Grade 6 is the most commonly used steel grade.
Chemical Requirements:
Composition %
Element | Grade 1 | Grade 3 | Grade 6 |
Carbon, max | 0.30 | 0.19 | 0.30 |
Manganese | 0.40 – 1.06 | 0.31 – 0.64 | 0.29 – 1.06 |
Phosphorous, max | 0.025 | 0.025 | 0.025 |
Sulfur, max | 0.025 | 0.025 | 0.025 |
Silicon | 0.18 – 0.37 | 0.10 min | |
Nickel | 3.18 – 3.82 |
Mechanical Properties:
Grade 1 | Grade 3 | Grade 6 | |
Tensile Strength, min, psi (MPa) | 55,000 (380) | 65,000 (450) | 60,000 (415) |
Yield Strength, min, psi (MPa) | 30,000 (205) | 35,000 (240) | 35,000 (240) |
CVN Impact (Charpy) Test:
Minimum Impact Test Temperature
Grade 1 | -50 (F) | -45 (°C) |
Grade 3 | -150 (F) | -100 (°C) |
Grade 6 | -50 (F) | -45 (°C) |
Heat Treatment:
Normalizing by heating to a uniform temperature not less than 1500 °F [815 °C] and cooling in air or in the cooling chamber of an atmosphere-controlled furnace.
