Types
The Haste Alloy pipe has gradually earned its place among the most used and trusted materials when making pipes. This is because of its resistance to the corrosive nature of chemical elements as well as its strength in harsh temperature and pressure conditions. The different grades of Hastelloy C276 pipes are suitable for specific environments.
Some types of Hastelloy pipes based on normalized manufacturing grade include:
- Hastelloy C-22: Commonly used in pulp and paper processing, chemical processing, waste treatment, and the production of chlorinated organic substances.
- Hastelloy C-276: This alloy is usually resistant to all forms of corrosion and can be used in the Chemical Process Industry, pollution control, oil and gas extraction and processing, and power generation.
- Hastelloy B-2: Often used in chemical processing, such as hydrochloric acid production and storage, and in the titanium and metal etching industries.
- Hastelloy X: Usually employed in gas turbines, aerospace engineering, pollution control, and high-temperature applications.
- N-105: Used in Aerospace, turbine components, and high-temperature and high-stress environments.
Commercial uses
The Alloy pipe's ability to withstand extreme environments makes it highly desired across chemical manufacturing, oil and gas, aerospace, power generation, and pulp and paper industries.
- Chemical processing: Hastelloy alloy pipes are frequently used in this space to transport highly corrosive substances such as acids, chlorides, and even wet cement. This is due to their ability to resist corrosion.
- Oil and gas industry: The pipes can be used in both offshore and onshore exploration and production activities, such as in deep-sea environments where the alloy's resistance to saltwater corrosion is critical for the long-term integrity of a pipeline.
- Pulp and paper industry: The pipes can be used in both chemical digestion and bleaching processes. The alloy's resistance to hydrochloric and sulfuric acids helps ensure durability and reduces maintenance costs.
- Aerospace: Hastelloy pipes are often used in the aerospace industry to manufacture parts that need to stand high temperatures and still maintain structural integrity, such as turbine components. Hastelloy X is particularly used in this field.
- Power generation: Hastelloy pipes are also used in nuclear power plants to contain highly corrosive fluids. They are also used in waste treatment systems that require corrosion-resistant materials to ensure safety and reliability.
Product specifications/key features
- Material composition: Hastelloy pipes are made from the combination of chemical elements they are resistant to. These elements include molybdenum, tungsten, nickel, chromium, and iron. Depending on the specific alloy grade the pipe will be used for, other elements, such as cobalt, manganese, and carbon, may also be added to improve the alloy's properties.
- Corrosion resistance: Hastelloy pipes can contain even the most corrosive materials, such as hydrochloric and sulfuric acids. This is because of the molybdenum and tungsten they are embedded with. Molybdenum helps resist chloride-ion-stressed corrosion, while tungsten provides extra resistance to high acidic concentrations.
- Durability: The alloy composition of the metals gives the pipes unparalleled durability and extended lifespan in both corrosive and non-corrosive environments. The pipes can also withstand extreme temperatures and high stress, which makes them a great fit in hazardous machining conditions.
- Temperature resistance: Depending on the specific alloy, Hastelloy pipes can maintain their strength and stability in either low or high temperatures. For example, Hastelloy C-276 is often used for high-temperature chemical processes, while N-105 is used for low-temperature applications.
- Formability and weldability: Hastelloy pipes can be easily formed and welded into complex shapes without losing their intrinsic properties. This makes them practical and adaptable for various applications.
How to choose
There are many hastelloy grades that have different compositions tailored for the different industries and harsh environments they contain. Therefore, there are some key factors to consider to help make the right choice for hastelloy pipe.
- Composition: Industries requiring extreme temperatures typically use Hastelloy X, while those needing corrosive chemicals prefer C-276. N-105 is also suitable for cryogenic applications.
- Cost: The choice of hastelloy pipe may come down to its cost compared to the longevity and resistance it will provide in a given environment. Hastelloy B pipes are generally cheaper than C alloys, while Hastelloy C-22 pipes are much more affordable than C-276.
- Physical properties: Information such as density, thermal expansion coefficient, and mechanical properties are important for helping select Which Hastelloy pipe to use based on the end-use requirements. For example, the high thermal expansion coefficient of the B-2 alloy makes it a suitable choice in environments with extreme temperatures, as it expands easily without cracking. Also, X- alloy's high density makes it stand high mechanical stress.
- Workability and fabrication: Choose the alloy that is easier to weld or machine for a highly corrosive environment, as they tend to be more difficult to work with. For example, C-276 is highly weldable, and N-105 is easy to machine.
Q&A
Are Hastelloy pipes worth the price?
Yes, the alloy has unmatched qualities that keep it worth every coin. The pipes can withstand extreme temperatures, retain strength without warping, resist chemical corrosion, and not crack or lose integrity over time. The pipes have even been used in hazardous oil and gas drilling, nuclear reactors, aerospace engineering, and chemical processing.
How to tell a genuine Hastelloy pipe?
Check for stamped information on the pipe to specify the alloy composition that meets the industry standards set by the ASTM. The print should be clear and visible even after the pipe is welded or subjected to adverse conditions. Other than the chemical makeup, other factors, such as material markings and physical tests, can help confirm the authenticity of the hastelloy. These include checking the mechanical properties, conducting non-destructive tests, and verifying the traceability of the material.
Does Hastelloy rust?
As strong and resistant as the alloy is, it is not entirely rust-proof. Stratton coined the term 'rust-resistant' to mean that such metals can, under some circumstances, be protected from the oxidation process that gives rise to rust. However, it can still occur, especially in less resistant alloys like B-2, used in non-corrosive environments. Nonetheless, it will still be resistant to corrosion and not fall apart as easily as some other weaker metals.
Can the alloy pipe be welded onto other materials?
Yes, it can be. When welding to mild steel or carbon steel, use a backing bar made from stainless steel or Hastelloy itself to help minimize dilution of the alloy. Also, use filler rods made from Hastelloy or compatible stainless steel to keep welded areas as corrosion-resistant as the original material.
