ASTM B622
ASTM B622 Alloy Seamless Pipes & Tubes
ASTM B622 is the standard specification for Nickel-Molybdenum-Chromium (Ni-Mo-Cr) corrosion-resistant seamless pipes and tubes. These alloys offer exceptional resistance to a wide range of aggressive environments, especially oxidizing, reducing, and mixed acid media. Materials under ASTM B622 are commonly used in highly corrosive chemical processing industries, pollution control equipment, and offshore applications due to their superior metallurgical stability and high mechanical strength.
It covers seamless pipes and tubes manufactured by hot- or cold-working processes and suitably heat-treated to achieve optimum corrosion resistance.
Key Features
Excellent resistance to pitting, crevice corrosion, and stress corrosion cracking
High performance in oxidizing & reducing environments
Superior resistance to chlorides, strong acids, and wet chlorine gas
Stable mechanical properties at elevated temperatures
Good formability, weldability, and fabrication versatility
Technical Specification
| Property | Description |
|---|---|
| Standard | ASTM B622 |
| Product Form | Seamless Pipes & Tubes |
| Manufacturing Process | Hot or Cold Worked + Solution Annealed |
| Grades | N10276, N06022, N10675, N06455, N06686 |
| Corrosion Resistance | Exceptional in aggressive chemical media |
| Key Applications | Chemical Processing, Pollution Control, Marine & Offshore, Petrochemicals |
Common Grades
- Hastelloy C-276 (UNS N10276)
- Hastelloy C-22 (UNS N06022)
- Hastelloy B-3 (UNS N10675)
- Hastelloy C-4 (UNS N06455)
- Inconel 686 (UNS N06686)
Product Types Under ASTM B622
Seamless Pipes
Seamless Tubes
Straight Length Tube
Coiled Tubing
Heat Exchanger Tubes
Condenser Tubes
Manufacturing & Processing
Hot or cold finished seamless manufacturing
Solution annealing at 2050°F (1120°C) followed by rapid quenching
Eddy current testing, hydrostatic testing & NDT as per ASTM B622
Dimensional inspection and PMI testing
Optional: Bright annealing & special surface finish for critical industries
Applications
Chemical and Petrochemical Processing
Pollution Control Equipment
Flue Gas Desulfurization Systems
Acid Production Plants (Sulfuric, Hydrochloric, Phosphoric)
Pulp & Paper Digesters and Bleaching Units
Waste Treatment & Offshore Oil & Gas
Pharmaceutical Equipment
Heat Exchangers & Pressure Vessels (ASME compliant)