金属-板材-图片7-泰国四个大气实验站典型钢种暴露2年表面照片

图7为典型钢种在四个大气实验站达叻、是拉差、曼谷、呵叻暴露两年年宏观腐蚀形貌。碳钢和典型低合金钢的向阳面锈层覆盖均比较完整，向阳面普遍比背阳面锈层要厚。碳钢背阳面要比低合金钢背阳面附着的锈多，且碳钢锈层覆盖物呈现比较均匀的棕红色。暴露两年后不同暴露地点的420qNH 背阳面金属光泽消失，表面覆盖物呈现红褐色。

Metal plate picture 7 surface photos of typical steel exposed for 2 years at four atmosphere experimental stations in Thailand

Figure 7 shows the macroscopic corrosion morphology of typical steel grades exposed in four atmospheric experimental stations for two years, namely, Dalat, shilasha, Bangkok and Korat. The rust layer on the sunny surface of carbon steel and typical low alloy steel is relatively complete, and the rust layer on the sunny surface is generally thicker than that on the back. The rust on the back surface of carbon steel is more than that on the back surface of low alloy steel, and the rust cover of carbon steel is uniform brown red. After two years of exposure, the surface metallic luster of 420qnh in different exposure sites disappeared, and the surface covering was reddish brown.