Effect of coating time and protective current on thickness of paint layer of Steel ST-37 by continuous painting

Corrosion is a major cause of the failure of the materials; especially in the cutting tools that mostly use carbon steel ST-37. Painting is performed on ST-37 to reduce or protect metal surface from the destructive effects of weather or the occurrence of corrosion. Besides, it is also applied to improve the esthetical and artistic value of metals. This study was conducted to determine how the influence of the current as well as the time of protection on the thickness of paint by continuous painting method. In this method, the specimens are hanged and hooked at the driving belt that put on the coating tub, and then the specimens are moved along tub during the painting process using the motor. The variables used for protection current are 1A, 2A, and 3A, while the variable times of paintings are 30, 45, and 60 minutes. The thickness of painting is investigated by Optical Microscope. As results, the thickness of the paint layer at a current of 1A, 2A, and 3A and time of 30 minutes are 154.15, 166.6 and 172.8 µm. For the coating time of 45 minutes, the thicknesses of the paint layer are 162.4, 181.2, and 191.6 µm. Meanwhile, for a coating time of 60 minutes with same above current, the thicknesses of paint are 235.3, 252.05, and 279.1 µm. The effective protection layer is found at a protective current of 1A, on 30 minutes of coating time with a thickness of paint layer is 154,15 µm. (paper)