PENGARUH PROSES PELENGKUNGAN DAN PEMANASAN GARIS PELAT BAJA KAPAL AISI E 2512 TERHADAP NILAI KEKERASAN DAN LAJU KOROSI

Abstract

Hull plate is the largest component of which has a high risk of damage due to corrosion, thus requiring repairs and maintenance costs are not small. This corrosion can occur during the production process of hull plates, which experienced a wide range of treatments including: cutting, bending and welding. To reduce the risk of damage due to corrosion, hence at the time of ship hull plate production process of prevention efforts required to avoid further damage. The process of bending steel hull plate was needed to form a ship body in accordance with the body plan in order to obtain the hull form that streamlines. This banding process can be done with the cold and hot working. Bending line heating method is very beneficial economically, but has some constraints, especially in setting the proper heating temperature in the line heating process. Line heating process can affect the microstructure of the plate, and the hardness of the plate. Line heating process also affects the corrosion rate of steel plate used in the media especially after the highly corrosive sea water. This research aims is to analyze the effect of bending process and lines heating of ship steel plate AISI E 2512 to changes in microstructure, hardness value of materials and also the corrosion rate. The method used is the method of experiments research. The specimen used is steel plate AISI-E 2512, which treated the bending process and lines heating using three kinds of bending radius R.67, R.100 and R.133. Tests conducted on the test specimen is micro structure, hardness testing, and corrosion test using sea water media with salinity 37 o /oo. The results showed that the corrosion rate of the best in the bending process was 0.126 mm/year occur in the bending process R 67. Whereas the best corrosion rate in the line heating process is 0.087 mm/year occur in the bending process R 67. Hardness testing results showed that the highest hardness in the bending process and the line heating process is 83.36 HRB and 80.38 HRB occur in the bending process R 133. The test results showed that the phase microstructure in the bending process and the line heating process is ferrite and pearlite. Key words: bending process, line heating, Hardness value, and Corrosion rate,