JT345耐大气腐蚀塔桅高强度结构钢的耐腐蚀性能

Anti-Corrosion Properties of Atmospheric Corrosion Resistant High Strength Structural Steel JT345 for Mast

对JT345耐大气腐蚀塔桅结构钢 (最大值 % :0 16C ,0 4 5Si,1 4 0Mn ,0 0 35P ,0 0 30S ,0 4Cu ,0 8Cr,0 0 2Nb)进行室内快速腐蚀、电化学腐蚀和室外大气曝晒腐蚀试验以及钢表面锈层分析。试验结果表明 ,JT345钢盐雾 (0 5 %NaCl,35℃ )和干湿交替 (0 3%NaCl+0 1g LNa2 SO4 +0 1g LNa2 SO3,室温 )年腐蚀速率均小于 0 6mm ,室外大气曝晒腐蚀速率为 0 0 2 5～ 0 0 4 6mm a ,达到CortenA钢 (% :0 10C ,0 4 0Si,0 4 8Mn ,0 0 94P ,0 0 19S ,0 5 2Cr,0 34Ni,0 32Cu)的实物水平。JT345钢的强度σb6 30MPa ,σs4 6 5MPa ,高于CortenA钢的强度 (σb4 95MPa ,σs345MPa ,δ531% ) ,并具有良好的塑性 (δ52 1% )。

The test of laboratory quick corrosion, electrochemical corrosion and outdoor atmospheric insolation corrosion as well as the analysis on surface rusty scale of atmospheric corrosion resistant high strength structural steel JT345 for mast (max %: 0.16C, 0.45Si, 1.40Mn, 0.035P, 0.030S, 0.4Cu, 0.8Cr, 0.02 Nb) have been carried out. The test results showed that the anti-atmospheric corrosion of steel JT345 was up to that of atmospheric corrosion resistant steel Corten A (0.10C, 0.40Si, 0.48Mn, 0.094P, 0.019S, 0.52Cr, 0.34Ni, 0.32Cu): the salt-fog (0.5% NaCl, 35 ℃) corrosion rate and dry-wet alternate ( 0.3% NaCl + 0.1g/L Na2SO4+0.1 g/L Na2SO3, ambient temperature) corrosion rate were all less than 0.6 mm/a and the outdoor atmospheric insolation corrosion rate was 0.025～0.046 mm/a, the strength - σb 630 MPa, σs 465 MPa of steel JT345 was higher than that of steel Corten A (σb 495 MPa, σb 345 MPa, δ5 31%), and the steel JT345 had excellent elongation (δ5 21%).