Atmospheric corrosion tests of steels were conducted for one year from April, 1962 to March, 1963 at 19 typical districts in Japan selected from meteorological viewpoint. The tests were designed to investigate the effect of meteorological factors on corrosion rates and corrosion tendency of steels.
The results obtained were as follows.
(1) The corrosion tendency was highest in industrial districts, and decreased in the following order: Pacific coastal districts, Japan-Sea coastal districts, inland districts.
(2) Corrosion rates were measured every month through the period, and the average corrosion rates decreased in the following order: Industrial districts (55.3mdd), Pacific coastal districts (20.4mdd), Japan-Sea coastal districts (18.8mdd), inland districts (5.1mdd). The average corrosion rate for the all districts was 21.9mdd.
(3) Among the meteorological factors such as temperature, humidity, precipitation, etc., the temperature effect is most important on the atmospheric corrosion of steels, even though sulfur dioxide and sea-salt particles (chloride) could become decisive in conjunction with the meteorological factors.