Jh. Zheng et al., PROTECTION OF DUPLEX STAINLESS-STEEL FROM LOCALIZED CORROSION BY SURFACE SUPERPASSIVATION, Materials science & engineering. A, Structural materials: properties, microstructure and processing, 174(2), 1994, pp. 120000045-120000049
So-called superpassivation surface treatment was conducted on a 22Cr-5
Ni-3Mo-N duplex stainless steel, and its pitting and stress corrosion
cracking (SCC) behaviour is studied in hot concentrated chloride solut
ions using cyclic polarization measurements and potential-controlled c
onstant load tests. The results indicate that ''superpassivated'' stee
l has an excellent pitting resistance and - consequently - also a very
good resistance to SCC since SCC of the duplex stainless steel initia
tes from pitting in the studied environments. Auger electron spectrosc
opy analyses show that the passivation treatment leads to a thick high
ly chromium-enriched passive film. Improved resistance of the duplex s
tainless steel to pitting and SCC is attributed to the existence of th
is him.