ASTM A333 Cryogenic Carbon Steel Pipe - Standard Full Name: ASTM A333/A333M-24 "Seamless and Welded Steel Pipes for Cryogenic Operations and Requirements of Notch Toughness". Product Type: Seamless / Welded (Straight Seam) Steel Pipe, with seamless being the primary type. Mainstream Grades: Gr.1, Gr.3, Gr.6 (Gr.8 for cryogenic applications). Applicable Scenarios: Cryogenic fluid transportation from -45℃ to -195℃, typically LNG/LPG, petrochemical, natural gas, and liquid nitrogen/liquid oxygen pipelines. 

Material Introduction:

Gr.1 (Basic Cryogenic Type): C≤0.30%, Mn 0.40–0.90%, Si≥0.10%. Low carbon, low impurities, balanced low-temperature toughness, suitable for operating conditions of -45℃ and above. Lowest cost, preferred for conventional cryogenic export projects

Gr.3 (Medium-temperature toughness type): C≤0.19%, Mn 0.31–1.06%, Si 0.13–0.37%, Ni 0.40max. Low carbon + trace nickel, stronger low-temperature impact resistance, suitable for -100℃ cryogenic applications. Mainstream for export LNG and ethane/propane pipelines.

Gr.6 (General cryogenic type): C≤0.19%, Mn 0.29–1.06%, Si 0.13–0.32%, Ni 3.18–3.82%. 3.5% nickel alloy, low-temperature performance surpasses carbon manganese steel, suitable for -101℃ LNG receiving terminals and core materials for ethylene cold boxes.

Gr.8 (Extreme cryogenic type, niche model): 9% nickel alloy, suitable for -195℃ liquid nitrogen/liquid oxygen, high cost, customized.

Product Advantages

Authoritative American Standards, High-Temperature Dedicated:ASTM/ASME dual certification (equivalent to SA106), the only universal carbon steel pipe in the global boiler, power plant, and petrochemical high-temperature fields. Specifically designed for high temperatures (450℃+) and high pressures (10~25MPa), unlike ordinary A53 (low pressure, normal temperature).

High-Temperature Performance Surpasses Ordinary Carbon Steel Pipes:Si Strengthening: High-temperature formation of a SiO₂ protective film, with creep resistance, oxidation resistance, and heat brittleness resistance 3 times higher than Q235. Grade B, allowable stress at 450℃: 180MPa, long-term stable without deformation or cracking.

Balanced Strength and Toughness, Safe and Reliable:Low sulfur and phosphorus (≤0.035%) + controlled rolling process: -29℃ impact ≥20J, suitable for both extreme cold and high temperatures. Seamless construction with no weld seams or leaks; 100% flaw detection + water pressure testing; zero leakage; long service life (30-50 years).

Welding/machining compatible with global standards: Grade B. Excellent weldability; standard welding rods/wires are sufficient; low preheating requirements; joint strength equal to the base material. Easy to cut, thread, bevele, and bend.

Full range of specifications; high cost-performance ratio.

Chemical composition (mass fraction %)

Mechanical properties

Statistics on the popular models and common specifications of carbon steel pipes

Select materials based on application

For general fluid transportation (water, gas, oil): 20#, Q235B, A53 Gr.B, STPG370

The best cost-performance ratio, globally applicable

For high-temperature / steam / boiler pipes: A106 Gr.B, 20G, 15CrMoG, P235TR1/P235GH

Better resistance to high temperature and pressure

For oil and gas pipelines: API 5L Gr.B, X42, X52, X60

High strength and good toughness, suitable for long-distance pipelines

For low-temperature environments (cold storage, LNG support): A333 Gr.1/Gr.3, 16MnDG

Resistant to low temperature without cracking

For structural pipes (supports, machinery, steel structures): Q355B (old 16Mn), St44.2, A36

High strength and good load-bearing capacity