Hastelloy B is a typical nickel-molybdenum corrosion-resistant alloy in the Hastelloy family. With nickel as the matrix and molybdenum as the main strengthening element, it has become a core material for addressing reductive corrosion conditions due to its unique compositional design and performance advantages. This alloy not only exhibits excellent corrosion resistance to reductive acids such as hydrochloric acid and formic acid but also maintains stable mechanical properties in the temperature range of 200°C to 1200°C. Additionally, it features good processability and formability, including cold rolling, hot rolling, forging, and welding. It is widely used in fields such as chemical engineering, energy, pharmaceuticals, and environmental protection, where high requirements for material corrosion resistance and reliability are demanded.
1. Chemical Composition
The chemical composition of Hastelloy B strictly complies with international standards (e.g., ASTM B333/B335/B336). The typical element content range is shown in the table below:
Element (Chemical Symbol) | Content Range (Mass Fraction) |
Ni | ≥65% |
Mo | 26%-30% |
Fe | 4%-6% |
C | ≤0.01% |
Si | ≤0.1% |
P | ≤0.02% |
S | ≤0.01% |
2. Physical Properties
Hastelloy B maintains stable physical properties at room temperature and high temperatures. The key parameters are listed in the table below (test conditions refer to ASTM standards):
Property Item | Value | Test Condition |
Density | 9.22 g/cm³ | 20°C |
Melting Range | 1330-1380°C | - |
Thermal Conductivity | 11.8 W/(m·K) | 20°C |
Thermal Conductivity | 14.5 W/(m·K) | 500°C |
Specific Heat Capacity | 435 J/(kg·K) | 20-100°C |
Coefficient of Linear Expansion | 11.2 ×10⁻⁶/°C | Room Temperature-100°C |
Coefficient of Linear Expansion | 13.5 ×10⁻⁶/°C | Room Temperature-500°C |
Electrical Resistivity | 1.38 ×10⁻⁶ Ω·m | 20°C |
Elastic Modulus | 210 GPa | 20°C |
3. Main Application Fields
Based on its resistance to reductive corrosion, high-temperature stability, and good processability, the core application scenarios of Hastelloy B are as follows:
Field | Specific Application Scenarios |
Chemical Engineering | Hydrochloric acid synthesis towers, hydrochloric acid storage tanks, hydrochloric acid heat exchangers, formic acid/acetic acid reactors, equipment for the reduction section of phosphorus chemical industry |
Energy Industry | Acidic oil and gas well pipes in oil and gas extraction, reactor liners for hydrocracking units, hydride processing equipment in the nuclear power field |
Pharmaceutical Industry | Corrosion-resistant reactors for pharmaceutical intermediates, sterile hydrochloric acid solution delivery pipelines, purification equipment for high-purity chemical raw materials |
Environmental Protection Industry | Wastewater treatment equipment containing high-concentration hydrochloric acid, corrosion-resistant components in flue gas desulfurization systems (reductive desulfurization environment) |
4. Usage Precautions
1. Avoid Oxidizing Environments: Hastelloy B has poor corrosion resistance to strong oxidizing media such as concentrated nitric acid and chromic acid, and it is strictly prohibited to use it directly in such working conditions. If the working condition contains a small amount of oxidizing impurities (e.g., Fe³⁺, Cu²⁺), chemical pretreatment must be performed in advance to remove them and prevent local corrosion of the alloy.
2. Welding Process Control: During welding, argon with a purity of ≥99.99% must be used for back and front protection to avoid oxidation of the weld area. No solution heat treatment is required after welding, but mechanical grinding or pickling should be used to clean the oxide scale on the weld surface to ensure consistent overall corrosion resistance.
3. Storage and Transportation: The product should be stored in a dry, well-ventilated indoor warehouse, away from humid environments and corrosive gases. During transportation, anti-collision packaging (e.g., wooden pallets, plastic protective films) must be used to prevent surface scratches or deformation that may affect performance.
5. Selection Recommendations
1. If the working condition mainly involves reductive acids such as hydrochloric acid and formic acid, and the operating temperature is ≤100°C, Hastelloy B plates or pipes are preferred to meet the corrosion resistance and forming requirements of the equipment.
2. If the application scenario involves high temperatures (800°C-1200°C) and a certain load (e.g., heating furnace tubes, reactor components), it is recommended to select Hastelloy B forgings or thick-walled pipes to utilize their excellent high-temperature mechanical stability.
3. If the working condition contains oxidizing components (e.g., nitrate, chlorate) or complex mixed media, detailed working condition parameters (medium concentration, temperature, pressure) should be provided. Professional technicians will evaluate the suitability, or recommend Hastelloy alloys with better oxidation resistance (e.g., Hastelloy C276).
