tailieunhanh - Lesson 24- Painting

Tham khảo tài liệu 'lesson 24- painting', ngoại ngữ, anh văn thương mại phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Lesson 24- Painting The corrosion of metals is a universal phenomena in the shipbuilding industry which causes serious direct or indirect losses year in year out. In accordance with the surroundings the corrosion may be classified as chemical medium corrosion atmosphere corrosion sea water corrosion and soil corrosion and the like. As it is known to all steel is widely used in shipbuilding since it acts as cheap structural materials. But its corrosion has turned out a big problem. Therefore effective anticorrosion precautions have to be taken to reduce the loss resulting from the steel corrosion. Up till now the protection coating on steel plates has remained one of the chief means of steel anticorrosion. The service life of a protection coating is related to various factors such as the rust removal on the surface the thickness of coating the composition of paint the painting process adopted etc. From a long practice and through a trial-and-error experiment people have come to know the quality of rust removal on steel surface is the most important factor in the performance of a protection coating. To minimize the hull corrosion marine steel plates must go through rust removing and primer painting. In general there are two ways to carry out the process. One way is to remove the rust and oxide on steel plates by shot-blasting or acid-pickling and then to paint them with a rust-proof primer. The other way is to shot-blast a whole section sometimes even a whole hull and then to paint it with a rust-proof primer as well. In order to raise the production efficiency an automatic production line for the steel plate pretreatment is to set up in a shipyard. The whole process may cover calibration rust removal primer painting drying and material marking of steel plates. With regard to the quality check of the rust removal there are generally two standards namely cleanness and roughness. The former refers to whether there is any remains of oxide on steel plate surface which .