3Long-term internal corrosion protection of chemical transport tank car

1. Substrate treatment: The painted surface must be thoroughly cleaned before painting, and it is required to be free of rust, scale, oil stain, water and dust. The derusting standard should meet the requirements of Sa2.5 or St3 in the corrosion grade of steel surface before painting in GB8923-88. 2. Construction temperature: The coating work should be carried out under the climatic conditions that the air temperature is above 5℃ and the relative humidity is below 85%, and the surface temperature of steel should be above 3℃ above the dew point temperature. Painting process: 1) Before painting, the components of the coating should be stirred evenly, mixed and stirred evenly according to the weight ratio required by the formula, and can be used after curing for half an hour. The prepared coating should be used up as soon as possible, and the applicable period is about 4 hours at 25℃. 2) Brush coating, roller coating and high-pressure airless spraying can be used for painting. In order to obtain better coating quality, high-pressure airless spraying is recommended. For edges, corners, welds, cuts and other parts, a coat should usually be brushed first, and then a comprehensive coating should be carried out according to the process requirements. 3) The thickness of the paint film shall be strictly controlled, so that 90% of the measured points reach the specified thickness; if the measured points fail to reach the film thickness, the film thickness shall reach 90% of the specified value. Recommended paint and proportion: 1. Dilling 482 metal accelerator is used as the direct bonding agent of metal to paint, with the thickness of 80 microns and the proportion of 20: 20. After thorough mixing, it is stirred evenly and dried for 20 hours after construction. 2. Dilin 441 or Dilin 704/ Dilin 958 wax colloid coating is a heavy-duty anticorrosive coating with a thickness of 1000 microns, and the mixing ratio is 20: 5. After thorough mixing, it is evenly mixed and dried at intervals, and the thickness of each pass is about 100-500 microns. 3, according to the construction requirements with matching diluent diluted to the appropriate construction viscosity. Dilin 8550 wax coating is resistant to long-term foaming of dichloroethane in pipes/pools, and also to long-term foaming of dichloroethane plus mixed acids such as hydrochloric acid/sulfuric acid/phosphorus pentachloride.