Hastelloy C-22 (UNS N06022 / Alloy C22) – Supplier of Round Bars, Seamless Tubes & Plates | Shanghai Hangbo Alloy Group

By Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier | ISO 9001:2015 | Est. 2012

Contact: sales@hangboalloy.com | hangbo@nickel-alloy.com | WhatsApp (Lisa): +86 13611656360

Quick Answer: What Is Hastelloy C-22?

Hastelloy C-22 (UNS N06022) is a versatile nickel-chromium-molybdenum-tungsten alloy designed for superior resistance to pitting, crevice corrosion, and stress corrosion cracking. With a high chromium content (22%), it offers significantly better resistance to oxidizing media (like nitric acid and wet chlorine) than Alloy C-276, while maintaining excellent performance in reducing environments. It is the premier choice for pharmaceutical industry reactors and chemical processing equipment where multi-purpose versatility is required.

Industry Pain Point: Many chemical plants handle mixed acid streams that fluctuate between oxidizing and reducing conditions. Standard alloys like C-276 excel in reducing environments but may struggle under strong oxidizing conditions. Hastelloy C-22 solves this by balancing its Mo and W content with high Cr, providing "universal" protection that reduces the risk of catastrophic failure in unpredictable process changes.

Key Properties at a Glance

Product Overview

Hastelloy C-22 is often referred to as the "Gold Standard" for multi-purpose chemical process vessels. Its metallurgy is optimized for stability:

• High Chromium (22%): Exceptional resistance to oxidizing acids (Nitric, Ferric salts) and wet chlorine.
• Molybdenum (13%) & Tungsten (3%): Provides localized corrosion resistance (pitting/crevice) in reducing media like Hydrochloric and Sulfuric acids.
• Low Carbon & Silicon: Prevents grain-boundary precipitation in the weld heat-affected zone, ensuring post-weld corrosion resistance without annealing.

Shanghai Hangbo Alloy Group provides C-22 in bars, plates, pipes, and fittings, all certified to ASTM/ASME standards.

Executive Standards

Chemical Composition (ASTM B574 wt.%)

Material Characteristics & Applications

Pharmaceutical Reactors: In the production of APIs (Active Pharmaceutical Ingredients), reactors encounter varying pH levels, from highly acidic catalytic steps to alkaline cleaning cycles. Hastelloy C-22 is chosen for its ability to resist Clean-In-Place (CIP) chemicals and its low leaching profile, ensuring batch purity.

Mixed Acid Environments: C-22 is exceptionally resistant to ferric chloride, cupric chloride, and contaminated organic/inorganic acids. Its PREN (Pitting Resistance Equivalent Number) of ~45 ensures safety in high-chloride desalination and waste treatment systems.

Pros & Cons & Global Project Cases

Frequently Asked Questions

Q1: Hastelloy C-22 vs C-276: Which should I choose?

Select C-22 if your process involves oxidizing acids (Nitric acid, wet chlorine) or mixed acids. C-22 has 22% Cr vs 16% in C-276. Select C-276 for purely reducing environments like strong Hydrochloric acid, as it is slightly more cost-effective and has higher Molybdenum.

Q2: How does C-22 perform in Hydrochloric Acid?

C-22 is excellent in HCl, maintaining low corrosion rates across all concentrations at room temperature. At boiling temperatures, it remains superior to stainless steels but may require B-3 for extreme conditions.

Q3: Is post-weld heat treatment (PWHT) necessary for C-22?

Generally, no. Due to its ultra-low carbon content, Hastelloy C-22 resists the formation of grain-boundary precipitates in the weld zone, maintaining corrosion resistance in the as-welded condition.

Q4: What is the PREN value of C-22?

The PREN (Pitting Resistance Equivalent Number) for Hastelloy C-22 is typically around 45-47 (calculated as %Cr + 3.3*%Mo + 1.5*%W), which is significantly higher than 316L (~24) or 904L (~34).

Q5: What is the maximum service temperature for C-22?

For pressure vessel service (ASME Code), C-22 is rated up to 677°C (1250°F). However, for aqueous corrosion service, it is typically used below 400°C.

Contact Shanghai Hangbo Alloy Group

Shanghai Hangbo Alloy Group - Complete Product Range

Production Process

Our material is manufactured using VIM (Vacuum Induction Melting) + VAR (Vacuum Arc Remelting) or ESR (Electroslag Refining) processes to ensure ultra-high purity and metallurgical integrity. The material undergoes precision machining and rigorous heat treatment (Solution Annealing/Aging) to achieve the specified mechanical properties and grain size consistency.

Testing & Inspection

To guarantee zero-defect delivery, all batches undergo comprehensive testing:

• UT/PT Flaw Detection: Ultrasonic and Penetrant testing to identify surface and internal defects.
• Mechanical Testing: High and low temperature tensile testing, impact testing, and hardness verification.
• Corrosion Testing: Intergranular corrosion tests and pitting resistance verification according to ASTM standards.

Quality Control

We implement a total quality management system with full-process traceability from raw material to finished product. All products are manufactured in strict compliance with ASTM, ASME, and AMS standards, accompanied by EN 10204 3.1/3.2 certificates.

Market Pain Points & Solutions

• Delivery Consistency: We address supply chain delays by maintaining a large inventory of raw billets and semi-finished products, ensuring rapid response times.
• Extreme Environment Tolerance: Our specialized melting processes ensure that our alloys maintain structural stability in highly corrosive and high-pressure environments where standard materials fail.

Deep Application Insights

• Petrochemical: Used in flare stacks and flare tips where resistance to high temperatures and sour gas corrosion is critical.
• Nuclear Power: Applied in reactor core components and control rod mechanisms due to its excellent radiation resistance and mechanical stability.
• Aerospace: Found in engine exhaust systems and turbine shroud rings where high fatigue strength and oxidation resistance are required.

Product Forms & Standards Comparison