How to deal with the damage on the surface of weathering steel plate?

1. Dust
The manufacture of pipes is often carried out in dusty sites. There are often many dusts in the air, which constantly fall on the surface of equipment and weathering steel plates. Cleaning method: water or alkaline solution can be used to remove dust on the surface of pipes and equipment. However, the adhesive dust needs to be cleaned up with high-pressure water or steam.

2. Scratches
In order to prevent the accumulation of process lubricants or products or dirt, it is necessary to mechanically clean the scratches and other rough surfaces on the weathering steel sheet.

3. Thermal tempering color and other oxide layers
If the weathering steel plate is heated to a certain high temperature in the air during the welding or grinding process, chromium oxide thermal tempering color will appear on both sides of the weld, the lower surface and the bottom of the weld. The heat-tempered color is thinner than the oxide protective film and is clearly visible. The color is determined by the thickness, which can be iridescent, blue, purple to pale yellow and brown. Thicker oxides are generally black. It is caused by staying at high temperature or high temperature for a long time. When any of these oxide layers appear, the chromium content on the surface of the weathering steel plate will decrease, resulting in a decrease in the corrosion resistance of these areas. In this case, not only should the heat tempering color and other oxide layers be eliminated, but also the metal layer of the weathering steel plate should be cleaned.

4. Rust spots
Before or during the manufacturing process, we sometimes see rust on the weathering steel plate or equipment, which indicates that the surface is heavily contaminated. The rust on the surface must be removed before the equipment is put into use. The thoroughly cleaned surface shall be inspected by iron test and/or water test.