硫酸溶液中のステンレス鋼の陽分極特性におよぼす塩素イオンの影響

抄録

The effect of cold-working, heat treatment and solution temperature on anodic behaviors of austenitic stainless steels of AISI Type 304 and 304L were studied in 1 N H₂SO₄ solutions containing various concentrations of chloride. With the increasing concentration of chloride ion, the critical current peak of both steels increased, and one more peak appeared in the potential range of −0.18∼−0.14 V (vs S.C.E.) in the Type 304 stainless steel. This peak increased by sensitization heat treatment and decreased by cold-working. The cold-working and ferrite precipitation by cold-working did not affect the critical potential of pitting formation, but the sensitization treatment at 675°C for 1 hr decreased the pitting potential of the Type 304 stainless steel. The breakaway rate of the passive film by pitting formation increased by cold-working.