Corrosion of mild steel in the tidal waters of the thames estuary I. Results of six‐months' and one year's immersion

Mild steel specimens have been exposed to the tidal waters of the Thames Estuary at nine points between Richmond and the sea and in four conditions of immersion: (a) fully immersed, (b) half immersed, (c) tidally immersed, (d) buried in mud at each site. The specimens have been examined after exposure for 6 summer months, 6 winter months and one year. Results show that the corrosion is partly aerobic and partly anaerobic (microbiological). The relative importance of the two contributions is not yet clear. Maximum corrosion rates (weight loss) and maximum depth of pitting were found to occur between Woolwich and Tilbury, i.e., in that part of the river most heavily polluted and most nearly anaerobic for the greater part of the year. The corrosion rates were of the same order as those obtained in the open sea by earlier workers.