Hastelloy Alloy Plate is a product made from a family of nickel-based superalloys primarily recognized for their exceptional and comprehensive corrosion resistance in the most aggressive chemical processing environments. Their high content of Molybdenum and Chromium allows them to resist virtually all corrosive media, including strong reducing acids, oxidizing acids, and wet chlorine, while offering superior resistance to pitting and stress-corrosion cracking. Hastelloy plate is mandatory for critical components like reactor vessels, heat exchangers, and scrubbers in the chemical processing, pharmaceutical, and pollution control industries.

Hastelloy Alloy Plate Description

HASTELLOY alloys, a proprietary trademark of Haynes International, are world-renowned high-performance nickel-based alloys primarily designed to excel in severe corrosive environments. Unlike Inconel or Incoloy which balance high strength and high temperature, HASTELLOY alloys prioritize ultimate corrosion resistance in both oxidizing and reducing media, often maintaining structural integrity in conditions where stainless steels and other nickel alloys fail rapidly.

Core HASTELLOY Alloy Grades Comparison

The HASTELLOY portfolio is categorized by its primary resistance mechanism (C-Type for versatile corrosion, B-Type for reducing acids, G-Type for strong oxidizing acids).

General Performance Characteristics of HASTELLOY Alloy Plate

1. Corrosion Performance

Broad Spectrum Resistance: The C-type alloys (C-276, C-22) are often described as "universal" corrosion materials, resisting both oxidizing (high Cr content) and reducing (high Mo content) conditions.

Localized Attack: Due to the high content of Mo and W, these alloys possess exceptionally high Pitting Resistance Equivalent Number (PREN), making them almost immune to pitting and crevice corrosion in most chloride environments.

Weldability and Sensitization: Modern HASTELLOY grades (C-276, C-22) have extremely low carbon and silicon, preventing the formation of detrimental grain-boundary precipitates in the heat-affected zone (HAZ), thus they can be used in the as-welded condition for many corrosive applications.

2. Mechanical and Physical Properties

Strength: HASTELLOY alloys offer superior tensile and yield strength compared to standard austenitic stainless steels, maintaining structural integrity under chemical attack and moderate pressure.

Ductility: As solid solution alloys, they exhibit excellent ductility and toughness, which aids in cold forming and fabrication processes.

Thermal Stability: Grades like B-3 and C-22 have been specifically formulated for improved thermal stability over older generations (like B-2 and C-4), minimizing the formation of deleterious intermetallic phases during elevated temperature exposure.

3. Fabrication

Forming: These alloys can be readily cold formed, although they exhibit a high rate of work hardening and require more power than conventional stainless steels.

Heat Treatment: They are typically supplied in the solution-annealed condition. Post-weld heat treatment is generally not required for corrosion resistance in the C-type and G-type grades.

Application Value of HASTELLOY Plate

HASTELLOY plates are essential where failure is not an option and where media are too aggressive for stainless or standard nickel alloys. Their value is measured in operational safety, reduced downtime, and extended service life:

Chemical Process Industry (CPI): Reactor vessels, heat exchangers, distillation columns, and piping exposed to highly corrosive acids (HCl, H₂SO₄, H₃PO₄), wet chlorine gas, and organic chlorides.

Pollution Control: Flue Gas Desulfurization (FGD) scrubbers, stack liners, dampers, and reheaters used in power generation to handle aggressive sulfurous/chloride condensate (C-276, C-22).

Pharmaceutical and Fine Chemical Production: Due to their low iron content and excellent corrosion resistance, they are used for high-purity processing equipment where metallic contamination must be minimized (C-22).