The crosion resistance of metals is mainly attributed to the above mentioned points (1) and (2). The dry corrosion of point (1) belongs to the chemical mechanism, while the wet corrosion belongs to the electrochemical mechanism. Points (3) to (5) belong to the further classification of points (1) and (2). The anti-corrosion mechanism of color coated steel plate is to use the coating to isolate the substrate from the corrosive medium and prevent the chemical or electrochemical reaction on the surface of the substrate. Therefore, the corrosion problems we should study should be classified as chemical corrosion and electrochemical corrosion on the surface of color coated steel plate.In terms of domestic demand, infrastructure investment and residents' end consumption will provide support. Chen Kexin said that in the first half of this year, there were many "short boards" in the fields of transportation, water conservancy, energy, information, pipe network and so on, which provided more room for growth. Considering the slowdown of infrastructure investment growth in the first half of the year, decision-making departments may increase infrastructure investment in the second half of the year to offset the weakening of external demand, which will increase the demand for 304 stainless steel plate. In addition, residents' terminal consumption can also help the growth of 304 stainless steel plate demand.