The Oxidation and Corrosion Resistance of Nitrided Iron Alloys.
Abstract
Potentiokinetic measurements show that the corrosion resistance of austenitic Fe-34w/o Ni alloys containing Mo or Ti is increased by nitriding in NH3:H2 gas mixtures to form respectively a homogeneous distribution of 3Mo2N precipitates or a modulated structure of Ti-N clusters. Resistance to aqueous corrosion is also increased in alloys containing nitrogen in solid solution. A commercial nitrogen alloyed steel, Nitronic 50, which has excellent corrosion resistance in the annealed condition is heavily attacked when tested after removal of nitrogen. High temperature oxidation studies of ferritic iron alloys in static air have been completed. No significant differences in weight gain is detected between alloys tested in the annealed, the nitrided or the nitrided and aged conditions for Fe-5w/o Mo and Fe-2.32w/o Cr alloys but superior oxide adhesion is observed on nitrided pure iron and alloys containing a dispersion of incoherent nitrides. Experiments on nitrided mild steel oxidised at 600 C demonstrate the resistance to fracture of oxides formed on nitrided alloys. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 27, 1981
- Accession Number
- ADA107516
Entities
People
- K. H. Jack
Organizations
- Newcastle University