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ASTM B622 Cylinder Tube Hastelloy Forging Pipe For Oil Equipment
Comprehensive Overview of ASTM B622 Cylinder Tube
Ⅰ Standard Positioning: The "Ultimate Solution for Extreme Corrosion" for Hastelloy Seamless Tubes
1.Scope of Application
ASTM B622 specifies the chemical composition, mechanical properties, and manufacturing requirements for nickel-molybdenum-chromium-based Hastelloy seamless tubes. It covers outer diameters (OD) ranging from 6 mm to 914 mm (0.25" to 36") and wall thicknesses from 0.3 mm to 50 mm (Schedule 5S to XXS). Typical grades include:
▶C276 (UNS N10276): A versatile corrosion-resistant alloy, resistant to wet chlorine, hydrochloric acid, and sulfuric acid;
▶C22 (UNS N06022): An ultra-pure Hastelloy grade, resistant to mixed acids (nitric + hydrochloric acid) and fluoride-containing media;
▶B3 (UNS N10675): A molybdenum-rich alloy, specifically resistant to concentrated hydrochloric acid (>30%) in reducing environments.
Ⅱ Chemical Composition: The "Corrosion-Resistant Gene" of Hastelloy
| Element | Typical Content (for C276, %) | Function Analysis |
|---|---|---|
| Ni | ≥ 57 (Matrix) | Forms a stable austenitic structure, resistant to non-oxidizing acids and Cl⁻ stress corrosion. |
| Mo | 15 – 17 | Provides resistance to pitting and crevice corrosion. |
| Cr | 14.5 – 16.5 | Forms a Cr₂O₃ oxide film, resistant to oxidizing acids and high-temperature oxidation. |
| W | 3 – 4.5 | Enhances resistance to erosion-corrosion. |
| C | ≤ 0.01 (Ultra-Low Carbon) | Prevents intergranular carbide precipitation and avoids sensitization in welded zones. |
Ⅲ Manufacturing Process: The "Corrosion Resistance Guarantee" from Melting to Forming
1. Melting
Adopts Vacuum Induction Melting (VIM) + Electroslag Remelting (ESR) to ensure uniform composition and freedom from inclusions.
2. Forming
▶Seamless Tubes: Produced via hot piercing → cold drawing process, with a wall thickness tolerance of ±8%;
▶Surface Treatment: Inner wall polished to Ra ≤ 0.8 μm (reduces fluid retention and prevents localized Cl⁻ enrichment-induced pitting).
3. Heat Treatment
Solution annealing at 1150℃ followed by water quenching.
4. Inspection
100% Ultrasonic Testing (UT, per ASTM E213) + Intergranular Corrosion Testing (per ASTM A262 Practice E). Tubes with defect equivalents > 1 mm are rejected.
Ⅳ Dimensional Specifications: Coverage of All Corrosive Scenarios
| Nominal Bore (NB) | Outer Diameter Range (mm) | Wall Thickness Range (mm) | Typical Application Scenarios |
|---|---|---|---|
| 1/8" – 2" | 6 – 60.3 | 0.3 – 10 (Sch 5S – 80S) | Chemical instrumentation tubes, nuclear waste liquid transportation (small diameter, high pressure). |
| 3" – 24" | 76.1 – 610 | 3 – 50 (Sch 40S – XXS) | Reactor connecting tubes, seawater desalination risers (large diameter, corrosion resistance). |
Ⅴ Application Fields: Hastelloy’s Role in Extreme Corrosion
1.Hydrometallurgy
2. Nuclear Waste Treatment
3. Hydrochloric Acid Regeneration
ⅥComparative Advantages: Superior Corrosion Resistance Over Inconel 625 (ASTM B444)
| Performance Indicator | ASTM B622 (C276) | ASTM B444 (Inconel 625) | Advantage Analysis |
|---|---|---|---|
| Resistance to Boiling HCl | 0.05 mm/year | 1.2 mm/year | C276 has 24x better corrosion resistance than 625. |
| Cl⁻ Pitting Resistance | No pitting (3.5% NaCl) | Mild pitting | C276 is suitable for marine/chemical Cl⁻ environments. |
| Maximum Service Temperature | 1093℃ (short-term) | 1200℃ | Inconel 625 offers better high-temperature performance, but C276 dominates in corrosion resistance. |
| Welding Process | No post-weld heat treatment | Post-weld solution annealing required | C276 improves construction efficiency by 40%. |
Ⅶ Inspection Standards: Stringent Quality Control Protocols
1.Material Verification: Direct-reading spectroscopy reports provided for each heat, with Ni content deviation ≤ ±0.5%;
2.Hydrostatic Pressure Test: 1.5x the working pressure;
3.Intergranular Corrosion Test: Per ASTM A262 Practice E, with corrosion rate ≤ 0.005 mm/year;
4.Surface Inspection: Endoscopic examination of inner walls, with no scratches allowed (to prevent localized Cl⁻ concentration).
Conclusion: The Irreplaceability of ASTM B622 Cylinder Tube
ASTM B622 defines the "corrosion resistance benchmark" for Hastelloy seamless tubes. Through high Mo content + ultra-low carbon design, double vacuum melting process, and full-scenario dimensional coverage, it has become the only choice for severe corrosion conditions (e.g., hydrochloric acid, fluoride-containing media, wet chlorine). Its core value lies in providing a "10-year leak-free" guarantee when stainless steel would be corroded through in such harsh environments.
DINGSCO Complete Production Chain:
SMELTING → FORGING → HEAT TREATMENT → MACHINING → HOT EXTRUSION
①Foundational Assurance in Smelting and Forging:
VIM furnaces ensure alloy purity; ESR furnaces further optimize internal structure. Forging yields diverse billets, laying a defect-free foundation for downstream processing and controlling material properties at the source.
②Precision Control in Intermediate Processing:
Heat treatment is customized for alloys. CNC machining enables high-precision forming, yielding semi-finished parts to ensure pre-extrusion billets meet forming specs.
③Synergistic Value of Hot Extrusion with Full Process:
The new hot extrusion press is part of an integrated system: High-purity alloys (VIM/ESR), dense forging microstructures, and heat-treated performance collectively enable stable extrusion of hard-to-form alloys. Produced complex components: seamless pipes, profiles; material utilization up 15-20%. Full-process efficiency cuts standard model lead times to 5-10 days.
④Quality and Delivery Assurance:
Every batch comes with EN 10204 Type 3.1 certification, inspected by our internal QC team. We support third-party audits (BV, SGS, etc.), and offer custom manufacturing per drawings with sample testing available.