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This paper reviews some of the important processes underlying high temperature degradation of structural materials used in the petroleum and petrochemical industries. Particular emphasis is palced in degradation processes involving the interaction of structural metals and alloys with environments containing sulfidizing, carburizing, and halogenizing species. In addition the effect of gaseous hydrogen environments at elevated temperatures and pressures on the mechanical properties of steels will be discussed. The mechanism of attack and the effect of alloying elements in these phenomena will be described and discussed.

Anodic protection (A.P.) for corrosion control is based on the principle of protecting a metal or alloy from corrosion by raising the electrochemical potential of its surface to a value at which a protective oxide film (passive film) is formed and maintained. The principles of design of anodic protection systems are not very well developed. This paper discusses several important basic design concepts and describes several equations which can be used for the design and optimization of anodic protection systems for corrosion control.

This paper presents a brief summary of the stress corrosion cracking experience of carbon steel in amine acid gas scrubbing units. In addition, it discusses the current views of the most probable mechanism of cracking of carbon steel equipment in amine acid gas scrubbing units and the probable role of the nature of the amine molecule.

Passivity and localized corrosion is discussed using iron, iron‐chromium, iron‐chromium‐nickel alloys and aluminium as examples. A brief description is given of the prevailing ideas regarding the nature of the passive film and the processes by which its protective properties are lost when breakdown of passivity and localized corrosion occurs.

The subject of this paper is high temperature corrosion in chlorine and hydrogen chloride gaseous environments. The discussion will be limited to metals and alloys such as iron and carbon steel, iron‐chromium alloys and stainless steels, nickel and nickel alloys which are of interest in the petroleum industry.

Aqueous solutions which contain H2SO4, H2S or mixtures of H2S and NH3 are corrosive to carbon steel and other commonly used alloys. Therefore, titanium has been evaluated as a possible construction material in these environments. This paper summarizes the results of a study of the corrosion, galvanic and hydrogen embrittlement behaviour of titanium in aqueous sulfidic and sulfate solutions. Variables discussed include the effect of solution pH, temperature and solution composition on the corrosion and electro chemical behaviour including galvanic effects of titanium. This paper also considers the effect of pH, temperature and mechanical loading rate (strain‐rate) on the ductility and embrittlement of titanium.

Sour water condensates are aqueous condensates which contain different concentrations of aggressive compounds such as HCl, H2S, CO2, NH3, cyanides, etc. These condensates which can be fairly corrosive are encountered in a variety of refinery processes ranging from atmospheric distillation units to hydrodesulphurisers and sour water strippers. This paper deals with the mechanism of corrosion by these condensates and the factors influencing corrosion in several typical refinery units. In addition, methods for corrosion prevention and control are also discussed.

This paper deals with the causes and mechanisms of internal corrosion of tanks used for the storage of crude oil and distillates. Services which are considered in this paper include crude oil storage tanks, gasoline blending and/or storage tanks and storage tanks for kerosene and heavier distillates. Fixed‐roof, as well as floating‐roof tanks, are considered. Methods for corrosion prevention and control are discussed.