Hastelloy B
About Hastelloy B
Name and Equivalent Name: Hastelloy B is also called Alloy B or Nimofer 2.4800. It complies with standards such as UNS N10001, ASTM B333, DIN/EN 2.4800, BS 3072: NA11, GB/T 14992: NS143, and AMS 5795. It is recognized under ASME SB-335, ISO 15156, and NACE MR0175 for its reliable performance in challenging environments.
Hastelloy B Basic Introduction
Hastelloy B is a corrosion-resistant superalloy primarily composed of nickel and molybdenum. It is designed to resist hydrochloric acid and other reducing agents across a wide temperature range. Its chemical stability makes it effective in chemical processing industries, especially in highly acidic environments.
The alloy offers excellent mechanical strength and thermal fatigue resistance at elevated temperatures, extending its applications to critical equipment like heat exchangers, reactors, and evaporators. Its metallurgical properties also ensure resistance to pitting, crevice corrosion, and stress corrosion cracking, making it ideal for severe industrial conditions.
Alternative Superalloys of Hastelloy B
Alternative materials to Hastelloy B include Hastelloy C22, Hastelloy C276, Inconel 625, and Monel 400. These alloys provide varying degrees of corrosion resistance, especially in oxidizing environments.
Hastelloy C-series alloys, such as C22 and C276, are more suitable for broader chemical environments involving oxidizing and reducing agents. Monel 400 offers superior resistance to seawater corrosion, while Inconel 625 excels in high-temperature oxidation resistance. Selection depends on the specific operational conditions and environmental requirements.
Hastelloy B Design Intention
Hastelloy B was designed for use in highly acidic conditions, specifically to combat corrosion from hydrochloric acid. It ensures operational safety in equipment exposed to aggressive environments by resisting pitting, stress corrosion cracking, and reducing environments.
The alloy is engineered to maintain structural integrity under mechanical stress and elevated temperatures, making it highly valuable for chemical reactors and evaporators. Hastelloy B ensures durability and reliability in demanding applications with a melting point of 1370°C and excellent creep strength.
Hastelloy B Chemical Composition
Hastelloy B’s chemical makeup emphasizes high nickel and molybdenum content, providing resistance to hydrochloric acid and reducing agents. Cobalt enhances strength, while minimal chromium content avoids issues in reducing environments.
Element | Content (wt%) |
|---|---|
Nickel (Ni) | Balance |
Chromium (Cr) | 0.5 - 1.5 |
Molybdenum (Mo) | 26.0 - 30.0 |
Iron (Fe) | 2.0 - 4.0 |
Tungsten (W) | - |
Cobalt (Co) | Max 3.0 |
Carbon (C) | Max 0.01 |
Hastelloy B Physical Properties
Hastelloy B offers high density, excellent thermal conductivity, and mechanical strength. These properties allow it to withstand harsh environments while maintaining structural integrity over time.
Property | Value |
|---|---|
Density (g/cm³) | 9.24 |
Melting Point (°C) | 1370 |
Thermal Conductivity (W/(m·K)) | 10.2 |
Modulus of Elasticity (GPa) | 205 |
Metallographic Structure of Hastelloy B Superalloy
Hastelloy B exhibits a face-centered cubic (FCC) structure typical of nickel-based alloys. The alloy’s microstructure enhances corrosion resistance by limiting carbide precipitation, which could otherwise lead to localized corrosion.
Proper control ensures minimal intermetallic phases, such as σ-phase, during heat treatment, which can weaken mechanical properties. The alloy’s high molybdenum content promotes resistance to crevice corrosion, while the absence of excessive chromium prevents issues in reducing environments and maintaining ductility and toughness.
Hastelloy B Mechanical Properties
The mechanical properties of Hastelloy B provide excellent creep resistance, strength, and durability at high temperatures.
Mechanical Property | Value |
|---|---|
Tensile Strength (MPa) | 690 - 790 |
Yield Strength (MPa) | 240 - 320 |
Creep Strength (500-900°C) | Strong |
Fracture Toughness | High |
Fatigue Strength (MPa) | ~350 |
Creep Rupture Life (500°C/10,000h) | Long |
Hardness (HRC) | B85 - 90 |
Elongation (%) | ~40 |
Elastic Modulus (GPa) | ~200 |
Key Features of Hastelloy B Superalloy
1. Outstanding Corrosion Resistance
Hastelloy B excels in resisting hydrochloric acid and other reducing agents, making it ideal for chemical processing industries. Its corrosion resistance extends to pitting and crevice corrosion in severe conditions.
2. High Mechanical Strength
The alloy demonstrates superior tensile and yield strength, ensuring reliability under mechanical stress. Its performance remains robust even at temperatures as high as 900°C.
3. Thermal Fatigue Resistance
Hastelloy B maintains structural integrity under thermal cycling, with excellent fatigue strength and resistance to thermal fatigue up to 1000°C.
4. Long Creep Rupture Life
With a creep rupture life of around 10,000 hours at 500°C, Hastelloy B ensures consistent performance under prolonged exposure to high temperatures.
5. Versatile Application Range
Hastelloy B is widely used in chemical reactors, evaporators, and heat exchangers due to its resistance to harsh chemicals. It is also employed in nuclear, marine, and aerospace equipment.
Hastelloy B Superalloy’s Machinability
Vacuum Investment Casting: Hastelloy B is not typically used in Vacuum Investment Casting due to its high molybdenum content, which makes it susceptible to cracking under thermal stress. Such precision casting methods prefer alloys with more ductility and better flow characteristics.
Single Crystal Casting: Hastelloy B is not recommended for Single Crystal Casting because it lacks the structural composition required to form single crystals. This process typically utilizes nickel-based superalloys for high-temperature creep resistance and turbine applications.
Equiaxed Crystal Casting: Although technically feasible, Hastelloy B is rarely used in Equiaxed Crystal casting due to its primary role in reducing environments. Alloys like Inconel, with enhanced oxidation resistance, are more common in equiaxed casting for critical applications.
Directional Casting: Hastelloy B is unsuitable for Superalloy Directional Casting because it does not meet the creep and thermal fatigue resistance required for turbine blades and other aerospace components formed through this technique.
Powder Metallurgy Turbine Disc: Hastelloy B is not typically applied in Powder Metallurgy Turbine Disc production, as its properties are better suited to chemical processing than to the high-temperature mechanical stresses required in turbine discs.
Precision Forging: Hastelloy B is suitable for Superalloy Precision Forging, especially for components in aggressive chemical environments. Its high strength and corrosion resistance make it valuable for chemical reactors and heat exchangers.
Superalloy 3D Printing: Superalloy 3D Printing with Hastelloy B is viable, offering complex geometries with excellent corrosion resistance. Additive manufacturing allows optimized designs for chemical equipment operating in harsh environments.
CNC Machining: CNC Machining of Hastelloy B requires advanced tools due to its hardness and tendency to work harden. Proper cooling and tooling ensure precision for chemical equipment components.
Superalloy Welding: Superalloy Welding is feasible with Hastelloy B, provided appropriate techniques are used to manage cracking risks. Post-weld heat treatments enhance joint integrity for critical chemical applications.
Hot Isostatic Pressing (HIP): Hot Isostatic Pressing (HIP) improves the performance of Hastelloy B components by eliminating porosity and enhancing strength, making it ideal for chemical reactors and pressure vessels.
Hastelloy B Superalloy Applications
Aerospace and Aviation: Hastelloy B finds limited use in Aerospace and Aviation due to its primary focus on chemical resistance. However, it may serve in auxiliary components exposed to corrosive environments, such as fuel systems and chemical handling equipment.
Power Generation: In Power Generation, Hastelloy B is used in heat exchangers and chemical reactors dealing with corrosive cooling mediums. Its resistance to chemical degradation ensures long operational life for critical equipment.
Oil and Gas: Hastelloy B is essential in the Oil and Gas sector, where it is used in pipelines, pumps, and valves exposed to hydrogen sulfide and acidic environments. It ensures reliability under severe conditions.
Energy: Hastelloy B plays a role in the Energy industry by providing durability and chemical resistance in components subjected to extreme temperatures and corrosive mediums, such as energy storage systems.
Marine: In Marine environments, Hastelloy B offers excellent corrosion resistance for desalination equipment and seawater handling systems, ensuring reliable operation under aggressive saltwater exposure.
Mining: Hastelloy B is applied in Mining operations where equipment must withstand corrosive substances and abrasive environments, such as slurry pipelines and chemical extraction systems.
Automotive: Though less common in Automotive applications, Hastelloy B can be used in exhaust systems and chemical handling equipment within electric vehicles, where corrosion resistance is required.
Chemical Processing: Hastelloy B is preferred in Chemical Processing due to its exceptional resistance to hydrochloric acid. It is widely used in reactors, heat exchangers, and storage tanks.
Pharmaceutical and Food: In the Pharmaceutical and Food industry, Hastelloy B ensures product purity and safety by resisting contamination from aggressive cleaning agents used in production equipment.
Military and Defense: Hastelloy B’s reliability in corrosive conditions makes it useful in Military and Defense applications, such as chemical warfare protection equipment and storage systems.
Nuclear: In the Nuclear sector, Hastelloy B provides corrosion resistance in cooling systems and chemical processing equipment exposed to highly corrosive materials.
When to Choose Hastelloy B Superalloy
Custom superalloy parts made from Hastelloy B are ideal when dealing with aggressive chemical environments, such as hydrochloric acid or other reducing agents. It excels in chemical reactors, heat exchangers, and pipelines requiring mechanical strength and corrosion resistance. Its use is also critical in industries where component purity, durability, and performance under thermal stress are vital.
This alloy should be selected when the operational environment involves high temperatures (up to 1000°C) and prolonged exposure to corrosive substances. Furthermore, Hastelloy B is the right choice in applications requiring components with long creep life, excellent fatigue strength, and thermal stability to maintain reliability in extreme conditions.
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