Design Of Ship Ballast System And Analysis Of Corrosion Resistance Of Key Components

With the development of China’s social economy,cruise travel is gradually welcomed by the public."Made in China 2025" clearly puts forward that "breaking through the design and construction technology of large-scale cruise ships" is one of the important signs of a strong shipbuilding country.As a ship protection system for maintaining the safe and stable navigation of cruise ships,ballast system has higher requirements than that of ordinary ships,so the design rationality and safety of key components are particularly important.Therefore,it is necessary to study the design basis and failure of cruise ballast system the effect of different working conditions on the corrosion resistance of key components in the same sea area.Taking the ballast system of large cruise ship as the research object,this paper analyzes the special requirements of cruise ship structure and its system composition.Combined with the domestic and foreign cruise ship design specifications,taking a large cruise ship as a template,this paper studies the layout of ballast cabin of cruise ship,stability requirements,system composition,working principle,layout characteristics,design principles based on safe return to port,calculation methods of ballast pipe diameter and other parameters specified by IMO and CCS.Through the design of auxiliary software,the parameter design and component selection of different types of cruise ballast system are realized,which provides a reference for the design of large cruise ballast system.The effects of Cl concentration,immersion time,sediment content and velocity on the static and dynamic corrosion of B10 and C90500,the key components of ballast system,the micro morphology of corrosion products,the corrosion morphology of surface,the corrosion degree of the two materials under different working conditions and the factors of working conditions were studied by means of surface analysis technology,electrochemical test and so on The influence mechanism of material corrosion provides data reference for the selection of key components of ballast system and the flow rate.The results show that the arrangement of ballast cabin is in accordance with the draft,initial stability height,restoring arm and weather balance standard required by IMO,and the calculation logic and design principle of key components are in accordance with the classification society.In the immersion test of simulated sea conditions,the impedance of the material increases with the increase of immersion time.Due to the strong penetration of chloride ion,the product film on the surface will be destroyed.Under the same soaking time,with the increase of chloride ion concentration,the impedance value of the two materials will decrease and the depth of corrosion pit will deepen.The immersion corrosion resistance of B10 is better than that of C90500 under the same working condition.The results show that with the increase of sediment concentration and velocity,the shear stress and mechanical force of sediment will increase,and the difficulty of the formation of product film will increase.There will be more cracks and crevices in the mixed layer,the corrosion resistance is weak,and the large mechanical effect will easily lead to "strain difference cell",which makes the corrosion rate maintain at a high level.The erosion corrosion resistance of B10 is better than that of C90500 under many working conditions.In conclusion,the relevant design and simulation test research carried out in this paper provide reference and data support for the design of ballast system of large cruise ship.