Electrophoresis, as a key process in the automotive coating process, can endow the body with good corrosion resistance. The quality of the electrophoretic paint film directly affects the appearance quality of the painted body and other properties. The electrophoretic quality not only depends on the coating process and the type of paint, but also is affected by the surface quality of the steel plate. Therefore, the author has done experimental research on the influence of the surface roughness of cold-rolled steel sheets on the quality of electrophoresis, using roughness meter, cupping Tester, impact testing machine and other test equipment to study the electrophoresis quality of cold-rolled DC06 steel sheets with different roughness. roughness, mechanical properties.
Among them, the roughness measuring instrument refers to GB/T2523-2008, the sampling length is 0.8mm, and the evaluation length is 4.8mm. The cupping test refers to the cupping test of GB/T9753-2007 paint and varnish. Impact resistance refers to GB/T1732-93 Determination of impact resistance of paint film.
Test Conclusions
1) When the roughness Ra of the steel plate is between 0.6 and 1.3 μm, the roughness of the electrophoresis plate is lower than 0.3 μm, and the roughness of the electrophoresis plate increases with the increase of the roughness .
2) The cupping values of all sample paint films are greater than 5mm, and the impact resistance values are greater than 70kg·cm, which can meet the general requirements . The roughness of the cold-rolled sheet increases, and the impact resistance of the paint film improves.
