Corrosion Studies of Iron In the Presence of Sulfur

Abstract

The authors give details of a study to determine effects of additives in sulfur cement and in surrounding aqueous solution when an interface of iron and sulfur was present in contact with water. No corrosion was observed when the iron was protected by even thin layers of sulfur cement. While information on corrosion at this interface was obtained it should not be misinterpreted insofar as performance of sulfur joints in cast iron pipe is concerned. Historical evidence and results of this study indicate properly prepared sulfur cement joints are satisfactory in bell and spigot cast iron water mains. The study consisted in partly or completely embedding an iron rod in a molten composition based on sulfur and immersing the resulting mass in water under various conditions.The addition of sodium chloride to the sulfur cement accelerated corrosion of the iron at the sulfur iron interface. Completely embedded iron rods in a silica-filled, sulfur cement were unaffected after two years' immersion in tap water, water at various conditions of pH and in the presence of aqueous sodium chloride.