表面沉积NaCl和NaHSO_3的低合金钢和碳钢在干湿交替条件下的腐蚀行为

CORROSION BEHAVIORS OF LOW ALLOY STEEL AND CARBON STEEL DEPOSITED WITH NaCl AND NaHSO_3 UNDER DRY/HUMID ALTERNATIVE CONDITION

利用Fourier变换红外(FTIR)光谱、XRD和SEM技术以及恒电流测试技术,研究了表面沉积NaCl和NaHSO_3的低合金钢和碳钢在干湿交替条件下的腐蚀行为.结果表明,低合金钢和碳钢的腐蚀速率都随着实验周期的延长而减小,且其失重量基本相同,低合金钢并未表现出比碳钢优越的耐蚀性.主要腐蚀产物为α-FeOOH,Fe_3O_4,γ-FeOOH和硫酸盐,此外还存在大量的δ-FeOOH,导致腐蚀速率降低.

The corrosion behaviors of low alloy steel P265GH and carbon steel Q235 deposited with NaCl and NaHSO_3 under dry/humid alternative condition were investigated by FTIR,XRD,SEM and galvanostatic method.The results reveal that under present experimental condition,corrosion rates of low alloy steel and carbon steel decrease with prolonging time and their mass losses are almost identical.Besides,corrosion resistance of low alloy steel P265GH is not better than that of carbon steel Q235.The corrosion products formed on the two steels are mainly composed ofδ-FeOOH,α-FeOOH, Fe_3O_4,γ-FeOOH and sulphate,among whichδ-FeOOH is predominant.The existence ofδ-FeOOH accounts for the decrease of corrosion rates of the steels.