C2024-20622 Liquid Metal Embrittlement (LME) Study Of A Zinc Rich Primer Applied Steel Vessel Plate And Galvanized Steel Plate At Elevated Temperature

Suresh Divi, Sri Krishna Chimbli - Zinc-rich primer-coated or galvanized ASME SA 516 grade 70 carbon steel vessels are commonly used in the chemical industry and refineries. Zinc-rich primer coatings and galvanizing are used to protect steel surfaces from corrosion. These are some of the most effective means of sealing critical equipment from moisture, protecting it from rust and corrosion. However, during weld repairs and post-weld heat treatment (PWHT), these vessels experience high temperatures (1000-1500oF) and could be susceptible to liquid metal embrittlement (LME).LME has been observed in several high-temperature applications and LME was described as the decrease in ductility of a metal caused by contact with liquid metal. It is characterized by a premature brittle failure of an otherwise ductile material when placed in contact with specific liquid metals. A plate from one of such vessels with zinc primer coating and a commercially available galvanized steel plate (ASME SA 5