| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel material superior in local corrosion resistance, which is resistant to local corrosion in a local corrosion-causing environment such as a saline-retaining part in the vicinity of a bottom plate in a crude oil tank, and to provide a corrosion test method. SOLUTION: (1) The steel material superior in the local corrosion resistance has such an immersion rest potential in a 3 mass% (hereafter described as %) NaCl aqueous solution exposed to air in a state having a clean surface free from oxide films and contaminants, as to be lower by 1 to 350 mV than that of pure iron containing 99.9% Fe in a similar state to the above. (2) The steel material further includes 0.0001-30% Zn. (3) These steel materials are used for the bottom plate as a component of a cargo tank of an oil tanker. (4) The corrosion test method for metallic materials is characterized by using a solid sulfur powder and a sheet with water-passing pores. COPYRIGHT: (C)2004,JPO&NCIPI
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