EFFECT OF VELOCITY AND NaCl CONCENTRATION ON THE EROSION CORROSION OF LOW CARBON STEEL

• Main Author: (NIM : 23107012); Pembimbing : Dr. Ir. Bambang Widyanto, SOMAWARDI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/17267
• Institution: Institut Teknologi Bandung

Corrosion erosion is the most common corrosion in piping system, it causes the metal damage by relative motion of fluid in surface of metal. High speed of fluid containing particles can causes erosion and low speed causes only <br /> <br /> <br /> corrosion. Corrosion erosion occurs only in critical speed. The impact of metal destruction caused by corrosion erosion is higher than the damage caused by either corrosion or erosion. <br /> <br /> <br /> Research was conducted on low carbon steel by varying fluid velocity. Liquid jet impingement is used as test equipment. The test was carried out for four hours to specimen (St.37) at 90O of impact angle. Degree of destruction of specimen was observed using stereo microscope and macro camera. Cross section observed by optical microscope, surface contour measured by dial gauge. Shear stress distribution on the surface of the specimen is simulated with <br /> <br /> <br /> Computational Fluid Dynamics (CFD). By this research is founded that the weight loss occurred at 2,1 m/s speed <br /> <br /> <br /> of fluid containing alumina or without alumina is higher than it occurred at 4,42 m/s. This result indicates that corrosion phenomenon dominant at low speed fluid. At high speed fluid (6,63 m/s), weight loss of material is the most greater compare to it occurred at 2,1 m/s or 4,42 m/s speed of fluid. This indicates that erosion is dominant than corrosion. Concentration of 3.5% NaCl has an optimal solubility of oxygen compared to 5% NaCl concentration. The more optimal solubility of oxygen, the higher weight loss of specimen due to autocatalytic process by Cl- ion. The specimen surface damage by 3.5% NaCl concentration is more dominant than 5% NaCl concentration.