Hastelloy C22 Bar Hot Rolled & Forged Bars EN 2.4602 Alloy Bar
Diameter 10 - 350mm Pass UT Test
Hastelloy C22 (EN 2.4602) is a premium
nickel-chromium-molybdenum-tungsten alloy renowned for its
exceptional corrosion resistance, high-temperature stability, and
mechanical strength—making its hot-rolled and forged round bars
(with a diameter range of 10-350mm and UT test qualification) ideal
for demanding industrial applications. Below is a comprehensive
overview of this alloy bar, covering its chemical composition,
mechanical properties, key characteristics, equivalent grades, and
typical applications.
1. Chemical Composition
Hastelloy C22’s corrosion resistance and mechanical performance
stem from its precisely balanced chemical composition, which
adheres to international standards (e.g., ASTM B574, EN 10088-1).
The typical composition (by weight percentage) is as follows:
| Element | Content Range (%) | Key Function |
|---|
| Nickel (Ni) | 56.0 min | Base metal; provides excellent ductility, toughness, and resistance
to stress corrosion cracking |
| Chromium (Cr) | 20.0 - 22.5 | Enhances oxidation resistance (even at high temperatures) and
resistance to pitting/crevice corrosion |
| Molybdenum (Mo) | 12.5 - 14.5 | Boosts resistance to reducing environments (e.g., acids) and
prevents localized corrosion |
| Tungsten (W) | 2.5 - 3.5 | Complements molybdenum to improve corrosion resistance in harsh
media (e.g., sulfuric acid) and enhances high-temperature strength |
| Iron (Fe) | 2.0 - 6.0 | Improves workability during hot rolling/forging and reduces alloy
cost without compromising performance |
| Cobalt (Co) | 2.5 max | Controlled to minimize potential embrittlement in high-temperature
services |
| Carbon (C) | 0.015 max | Low carbon content prevents carbide precipitation (a common cause
of intergranular corrosion) during welding or heat treatment |
| Silicon (Si) | 0.08 max | Reduces oxide formation and improves castability/forgability |
| Manganese (Mn) | 0.5 max | Aids in deoxidation during manufacturing and enhances ductility |
| Phosphorus (P) | 0.02 max | Minimized to avoid brittleness and corrosion susceptibility |
| Sulfur (S) | 0.01 max | Strictly controlled to prevent hot cracking during welding and
forging |
2. Mechanical Properties
The hot-rolled and forged Hastelloy C22 bars (diameter 10-350mm)
exhibit excellent mechanical strength and ductility, even at
elevated temperatures. Below are the typical mechanical properties
(tested at room temperature, per ASTM B574):
| Property | Specification (Typical Value) | Test Standard |
|---|
| Tensile Strength (σb) | ≥ 690 MPa (100 ksi) | ASTM E8/E8M |
| Yield Strength (σ0.2) | ≥ 310 MPa (45 ksi) | ASTM E8/E8M |
| Elongation at Break (δ) | ≥ 40% | ASTM E8/E8M |
| Hardness (Brinell, HBW) | ≤ 210 | ASTM E10 |
| Impact Toughness (Charpy V-notch) | ≥ 100 J (74 ft-lb) at -196°C (-321°F) | ASTM A370/ASTM E23 |
Note: Mechanical properties can be adjusted via post-forging heat
treatment (e.g., solution annealing at 1120-1170°C followed by
rapid quenching) to optimize strength or ductility for specific
applications.
3. Key Characteristics
Hastelloy C22 hot-rolled and forged bars stand out for their unique
combination of properties, making them superior to many other
nickel alloys:
Exceptional Corrosion Resistance:
It resists a wide range of aggressive media, including sulfuric
acid, hydrochloric acid, acetic acid, seawater, and
chloride-containing solutions. Unlike lower-grade alloys, it avoids
pitting, crevice corrosion, and intergranular corrosion—even in
harsh environments like chemical processing plants or offshore oil
platforms.
High-Temperature Stability:
The alloy maintains its mechanical strength and oxidation
resistance at temperatures up to 1093°C (2000°F). It is resistant
to “hot corrosion” (attack by molten salts or sulfur-rich gases),
making it suitable for high-temperature applications like furnace
components or gas turbine parts.
Excellent Fabricability:
The hot-rolled and forged bars offer good ductility, enabling easy
machining, welding (compatible with TIG/MIG welding processes), and
forming (e.g., bending, flanging). Low carbon content eliminates
the need for post-weld heat treatment to restore corrosion
resistance.
UT Test Qualification:
All bars (10-350mm diameter) pass Ultrasonic Testing (UT) per
standards like ASTM A609 or EN 10228-3. This ensures the absence of
internal defects (e.g., cracks, inclusions) that could compromise
structural integrity in critical applications.
Toughness at Cryogenic Temperatures:
Unlike many alloys that become brittle at low temperatures,
Hastelloy C22 retains high impact toughness even at -196°C
(-321°F), making it suitable for cryogenic equipment (e.g., liquid
natural gas storage).
4. Equivalent Grades
Hastelloy C22 is recognized under various international standards
and has equivalent grades across regions, ensuring consistency in
performance and interchangeability:
| Standard Organization | Grade Designation | Common Name |
|---|
| ASTM (USA) | UNS N06022 | Hastelloy C22 |
| EN (Europe) | 2.4602 | Nickel Alloy 2.4602 |
| DIN (Germany) | NiCr22Mo9W | — |
| JIS (Japan) | NW 20602 | — |
| ISO | NiCr22Mo9W | — |
These grades share identical chemical and mechanical properties, so
Hastelloy C22 bars (EN 2.4602) can be used as direct replacements
for UNS N06022 or DIN NiCr22Mo9W in global projects.
5. Applications
Thanks to its versatile performance, hot-rolled and forged
Hastelloy C22 bars (10-350mm diameter) are widely used in
industries requiring corrosion resistance, high-temperature
strength, or structural reliability. Typical applications include:
Chemical Processing:
Reactors, pressure vessels, heat exchangers, and piping for
handling acids (sulfuric, hydrochloric), solvents, and corrosive
intermediates.
Oil & Gas Industry:
Downhole components (tubing, casings), offshore platform
structures, and wellhead equipment—resistant to seawater and sour
gas (H₂S).
Pharmaceutical & Food Processing:
Equipment (mixing tanks, conveyor parts) that requires corrosion
resistance to clean-in-place (CIP) solutions and compliance with
hygiene standards (e.g., FDA).
High-Temperature Equipment:
Furnace heating elements, gas turbine combustion chambers, and
aerospace components—withstands elevated temperatures and
oxidation.
Environmental Engineering:
Wastewater treatment systems, flue gas desulfurization (FGD) units,
and air pollution control equipment—resistant to acidic effluents.
