Study and Analyze Corrosion Rate of the Submerged Structure of Submarines and Evaluate the Performance of Various Painting Systems for Better Structure Protection (M.Sc. Thesis)
- Karachi : Institute of Materials Sciences and Research Pakistan Steel, 1997
- 120 p. : ill
ABSTRACT :
Corrosion due to the marine environment has been a major problem faced by the marine industries and installations all over the world. This problem is more severe for Pakistan Navy as the seawater around Karachi harbour is more polluted and aggressive as compared to the other harbours. The submarines and ships of Pakistan Navy spends most of their time in this hostile environment because PN Dockyard is the only major Naval Base, which looks after the maintenance and operational aspects of these ships and submarines. In the present work various panels were prepared from the material actually used for the construction of submarine's structures. These panels were immersed around PN Dockyard and their corrosion rates were determined by using the weight loss method. Corrosion products removed from these panels have been analyzed quantitatively and qualitatively by performing laboratory analysis, i.e. chemical analysis and x - ray diffraction respectively. Four different paint systems have also been developed in collaboration with the local manufacturers (Berger and Buxly Paints Pvt. Limited). These paint systems were tested in comparasion with the imported paints and after series of tests i.e. laboratory as well as field tests, the evaluation of these paint systems has been carried out in accordance with ASTM Standards. Based on the experiments performed and studies carried out, using the facilities of IMS&R, Buxly, Berger and PN Dockyard laboratories, it is concluded that, the corrosion rate around PN Dockyard is approximately 21 mpy (mils per year) and corresponding reduction in the plate thickness is approximately 0.6 mm per year. The best paint system is the Berger Chlorinated Rubber based paint system. Mathematical model built on the basis of observed data can provide the values of weight loss with good approximation of the experimental data.