中文摘要：

采用极化曲线、电化学阻抗谱、x射线衍射分析（XRD）及扫描电子显微镜（SEM）等方法，研究酸性土壤中不同pH值模拟硝酸型酸雨对X70钢腐蚀行为的影响。结果表明，酸性土壤中模拟硝酸型酸雨对埋地X70钢的腐蚀起加速作用；XRD结果表明X70钢表面的腐蚀产物主要由Fe2O3和SiO2组成；SEM分析表明随着淋溶液pH值的升高试样表面粗糙度逐级降低，气孔数量逐渐减少。

英文摘要：

The effects of simulated nitric acid rain in different pH value on X70 steel in acidic soil were studied by means of polarization curves, electrochemical impedance spectroscopy（eis）, x-ray diffraction（xrd）, scanning electron microscopy（sem） etc. The results revealed that simulated acid rain could heavily increase the corrosion rate of X70 buried; The results of X-ray showed that corrosion products mainly consist of Fe2O3, SiO2; The results of SEM showed that with the increasing of pH value surface roughness was falling and quantities of microspores decreasing.