Studies on Rivet-Head Corrosion and its Prevention

Abstract

Inspections of many ship bottoms informing the authors that the rivet-head is more serverely corroded than any other parts, they studied and investigated these phenomena with various methods. Results of our investigation are shown as follows: (1) Galvanic corrosion due to millscale are most fundamental. (2) Escape of hydrogen from rivet causes paint film fracture. (3) Pitting corrosion due to stray current. (4) Effect of steel quality and microstructural characteristics of rivet bars. (5) Characteristics of paint film and painting system are also effective. (6) Erosion due to velocity and some various stresses (external and internal) have serious influence. (7) Bacterial corrosion is worth due consideration in some cases. We recognized that for the preventive measures of these rivet corrosions the painting process and pretreatment of painting are most important.