Hastelloy B2 and B3 Material are nickel-molybdenum alloys renowned for their exceptional corrosion resistance in harsh environments. While both are widely used in chemical processing, petrochemicals, and energy industries, their distinct compositions and performance characteristics make them suitable for different applications.
Chemical Composition of N10665 and N10675
Hastelloy B2 contains approximately 65–70% nickel (Ni) and 26–30% molybdenum (Mo), with minimal chromium (Cr ≤1%) and iron (Fe ≤2%) . Its low carbon content (≤0.02%) enhances resistance to intergranular corrosion.
Hastelloy B3 adjusts this formula by slightly reducing nickel (≈67%) and increasing molybdenum (28–32%), while adding small amounts of chromium (1–3%) and silicon (Si) for improved thermal stability.
Corrosion Resistance between alloy B2 and Alloy B3
Hastelloy B2 is superior in hydrochloric acid (HCl) and other non-oxidizing acids, making it ideal for HCl production equipment and chlorinated solvents. However, it struggles in oxidizing conditions (e.g., nitric acid) and high-temperature chloride environments .
Hastelloy B3 retains B2's resistance to HCl but extends performance to oxidizing and mixed-acid environments, including sulfuric (H₂SO₄) and phosphoric (H₃PO₄) acids. It also resists localized corrosion (e.g., pitting, stress corrosion cracking) better due to its refined composition .
High-Temperature Performance of Alloy N10665 and alloy N10675
Hastelloy B2 performs well at moderate temperatures but may oxidize or degrade in prolonged high-heat conditions (e.g., >400°C) .
Hastelloy B3 shines in high-temperature and high-pressure environments (e.g., chemical reactors, heat exchangers) due to its enhanced oxidation resistance and minimized phase instability.
Mechanical Properties of Hastelloy B2 and hastelloy B3
Tensile Strength: B2 exhibits higher tensile strength (≥690 MPa) compared to B3 (≥620 MPa) .
Ductility: Both alloys offer excellent elongation (≥40%), but B3's improved thermal stability ensures better toughness during thermal cycling.
Stress Corrosion Cracking: B3's optimized composition reduces susceptibility to stress-induced cracking in chloride-rich environments.
Fabrication and Welding of alloy B2 and alloy B3
Alloy B2 is easier to machine and weld using standard methods (TIG, MIG) without requiring post-weld heat treatment.
Alloy B3, while weldable, demands stricter control of welding parameters (e.g., heat input) to avoid cracking. Its superior thermal stability, however, simplifies hot forming processes.
Hastelloy B2 & Hastelloy B3 Material Manufacturer, Supplier
As a trusted stockist and exporter with a decade and a half of global experience, HT PIPE offers an extensive range of industrial materials: Hastelloy B2 pipes, sheets, alloy bars, plus precision-engineered fittings, flanges, and couplings. Contact our team for free, customized quotes and product brochures.
