Effect of Residual Stress on Corrosion Polarization Mechanism of the ASME SA-179 Material in Corrosive Environment

The aim of this research is to investigate the polarization behavior of corrosion on the SA-179 material, which is commonly used in heat exchanger equipment. The existence of tube components as a conduit for cooling fluid such as water or other solutions is the most significant feature of the temperature control of the heat exchanger. The cooling media is frequently a corrosive solution, which may degrade the heat exchanger material's performance. Furthermore, the corrosion process could be accelerated by residual stress generated by the shape of the heat exchanger tube formed by the cold working procedure. The SA-179 Carbon Steel Material, which has been manufactured to represent a heat exchanger tube, metallographic observations, polarization measurements, and macro-observations on the surface of the corroded area have been carried out in this work. To produce the strain and residual stress conditions seen in the elongation and compression segments, the SA-179 material was loaded using the U-Bend method. To generate a corrosion polarization curve that describes corrosion behavior under the conditions of plastic strain and residual stress, the potentiostatic measurement has been applied. Plastic deformation has an effect on grain boundary conditions in the SA-179 material, according to the average grain size discovered in this work. The polarization behavior is also influenced by this circumstance. The corrosion potential value is − 0.766 V at a current of 1.9 × 10–7. A in the absence of strain and residual stress. Furthermore, the corrosion potential is demonstrated to be − 0.823 V at a current of 6.8 × 10–7. A under conditions with U-Bend deformation. According to this phenomenon, plastic deformation has a bigger Nobel effect on SA-179 material in a corrosive environment, but has a higher corrosion rate if the corrosion process has already occurred.