Research on the impact performance of polyurethane coating on the steel structure surface

Focusing on the 3060 Goal, China builds a large energy base in Inner Mongolia. The steel structure facilities are subjected to long-term impacts from hard particles in the desert environment. Damage to the surface coatings of the steel structures resulted in reduced durability, and safety. The impact test of polyurethane coating was carried out by using an automatic ball impactor, the strain field of PU coating under impact load was collected by combining with Digital Image Correlation, the damage degree of PU coating was investigated by using Laser Scanning Confocal Microscopy, and elastic-plastic properties of PU coating were also studied. The results show that at the same impact height, the indentation depth of the substrate was Steel substrate > PU coating-steel substrate bilayer system, indicating that the PU coating played a better role in protecting the steel substrate. The compressive strain area at the impact contact point of the PU coating-steel substrate bilayer system increased with the increase of impact height, and the surface of the coating appeared to have different degrees of cracks and spalling. The dynamic hardness increases and then decreases with the increase of impact height, and the dynamic hardness value is the largest when the impact height is 30 cm.