Environmentally Assisted Cracking in the Chemical Process Industry. Stress Corrosion Cracking of Iron, Nickel, and Cobalt Based Alloys in Chloride and Wet HF Services

摘要

Many different alloys are used in the fabrication equipment for the chemical process industry (CPI) and the most common of these alloys are iron base (stainless steels). During service, the primary cause of failure of engineering alloys is stress corrosion cracking (SCC). Although the occurrence of environmentally induced cracking might be prevented by reducing the level of tensile stresses on components, this approach is seldom practiced. In some cases, failure can be avoided through a proper alloy selection based on results from laboratory testing. The aim of this paper is to assess the predictive capabilities of laboratory testing for cases of SCC in the CPI. Instances of chloride cracking and wet hydrofluoric acid (HF) cracking in the field are analyzed based on results from laboratory testing.