1. Core Matrix Elements
The core matrix is composed of nickel (Ni) and copper (Cu), with nickel as the primary element (accounting for 60%–70%) and copper as the secondary core element (accounting for 28%–34%). Other trace elements include iron (Fe, ≤2.5%), manganese (Mn, ≤2%), silicon (Si, ≤1%), etc.
The core matrix is nickel (Ni) (as the base element, accounting for 40%–60%), supplemented by high-content chromium (Cr) and molybdenum (Mo). Different Hastelloy grades are adjusted based on this core system, and some grades also add tungsten (W), iron (Fe), cobalt (Co) and other elements to optimize performance.
Hastelloy C276: Ni (balance), Cr (14.5%–16.5%), Mo (15.0%–17.0%), W (3.0%–4.5%), Fe (4.0%–7.0%).
Hastelloy B2: Ni (balance), Mo (26.0%–30.0%), Fe (≤2.0%), Cr (≤1.0%).
2. Key Differentiating Elements
Monel alloys rely on the Ni-Cu binary system to achieve corrosion resistance, especially in seawater, hydrofluoric acid and other media.
Hastelloy alloys rely on the synergistic effect of Cr, Mo and W to form a dense passivation film on the surface, thus obtaining excellent corrosion resistance to strong oxidizing media, reducing media and mixed acids, which is far superior to Monel alloys in harsh corrosive environments.
