Hastelloy C22 (UNS N06022), a nickel-based high-temperature and corrosion-resistant alloy, is widely used in chemical industries due to its outstanding comprehensive properties. With high contents of Cr, Mo, and other elements, this alloy demonstrates exceptional corrosion resistance against both oxidizing and moderately reducing environments, particularly excelling in resisting oxidative acid corrosion. Its excellent resistance to stress corrosion cracking and localized corrosion makes it ideal for harsh applications, including strong inorganic acid solutions, chloride-containing media, organic acids, and seawater.
How to achieve optimal corrosion resistance and mechanical properties in Hastelloy C22 (UNS N06022)? Three key process optimizations are essential:
1, Melting Process Optimization
Precise composition control: Mo content increased from 12.8% to 13.0%;
Vacuum melting refining time extended by 10 minutes to reduce macrosegregation.
Significantly improved resistance to intergranular corrosion.
2, Hot Working Process Improvement
Increased rolling ratio and reduced final rolling temperature to refine the microstructure;
Achieved grain size Grade 5 or better (per ASTM E112) after heat treatment;
3, Solution Heat Treatment Enhancement
Reduced water quenching time after soaking from 190 sec to 60 sec;
Increased initial cooling temperature to suppress intergranular secondary phase precipitation;
Corrosion rate significantly improved from 1.1 mm/y to 0.65 mm/y (ASTM G28 Method A)
Elongation increased from 50% to 65% (ASTM E8), greatly enhancing workability and service performance.
As a professional nickel-based alloy solutions provider, Tiny Alloy has successfully improved the overall performance of Hastelloy C22 through these process optimizations.
