This work is composed of part-1 and part-2. Part-1 was reported in Bull. Soc. Sea Water Sci. Jpn., 57,(2), pp.93-102 (2003). This manuscript is part-2 and intended for the conditions which participate in corrosion velocity. Some figures and tables are quoted from excellent corrosion textbooks shown at“References”. I wish to express my gratitude to the authors and the publishers.