The effect of temperature on the corrosion rate of iron-carbon alloys

Abstract

Temperature has a significant effect on the progress of corrosion processes on the surface of metals and alloys. The corrosion behavior of iron-carbon alloys in a 0.1 N solution of sulfuric acid at various temperatures was studied. The parameters of the corrosion rate for the investigated system «iron-carbon alloy – 0.1 N solution of sulfuric acid» at different temperatures were determined. It was found that when the temperature increases by 10 °C, the dissolution of the iron-carbon alloy accelerates by an average of 2.3 times. The values of the activation energy of the corrosion process for the investigated iron-carbon alloys are determined, which indicate that the corrosion processes in a solution of sulfuric acid proceed by an electrochemical mechanism. It is established that when the carbon content in the alloy increases, the energy of corrosion activation increases, which means that the beginning of corrosion processes on the surface of iron-carbon alloys occurs later. After the beginning of corrosion, the dissolution of metal under the influence of an aggressive environment occurs faster on the surface of alloys with a high carbon content. Large mass losses of iron-carbon alloys with a high carbon content are caused by the presence on their surface of a greater number of «iron – carbon» galvanic couples. The more such pairs, the more likely and stronger corrosion.