Carbon steel piping systems in several plants have failed under different applications, due to erosion-corrosion. This paper presents a variety of case histories where single-phase and two-phase steam flows, caused erosion-corrosion damage mainly at turn points of elbows and heat exchanger tubes. It was observed that the presence, even of a small amount, of the vapor phase can significantly increase the velocity of the condensate. The results of metallographic, SEM, elemental (EDX), X-ray Photon Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) analyses and corrosion rate calculated for each case are presented. The main causes of the failures are discussed and
recommendations are provided to avoid similar problems in the future.
Keywords: Steam condensate, piping system, erosion-corrosion, air cooler tubes, elbows, impingement, carbonic acid, thermal conductivity.