A prepitting procedure to generate a single pit of ‘controlled’ depth on a steam turbine disc steel has been developed using disodium tetraborate-sodium chloride solution. The optimal conditions for controlled pit generation and growth were obtained by varying the ratio of tetraborate to chloride ions and applying an anodic current of 10 mA. The procedure can be used to produce a single pit on a cylindrical specimen, which can be used subsequently for stress corrosion cracking or corrosion fatigue tests. The growth rate and the shape of the pits have also been investigated.
Get full access to this article
View all access options for this article.
References
1.
ZhouS. and TURNBULLA.: Fatigue Fract. Eng. Mater. Struct., to be published.
2.
ASTM Standard E8-94a, ‘Standard test methods for tension testing of metallic materials’, ASTM, Philadelphia, PA, 1994.
