通过国产Q235钢与X70钢U形试样在新加坡现场埋样试验，应用腐蚀形貌观察、裂纹扩展形貌观察、腐蚀产物的分析以及土壤理化性质分析等手段研究Q235钢和X70钢在新加坡土壤中的应力腐蚀行为特征，初步研究国产钢在国外典型土壤环境中的耐蚀性。结果发现，新加坡土壤中含有较多的硫化菌，硫化菌降低了硫酸盐还原菌的破坏作用；Q235钢与X70钢U形试样在新加坡酸性土壤中埋样1年后均发现了应力腐蚀开裂(Stress corrosion cracking, SCC)，表现出明显的SCC敏感性，X70钢应力腐蚀敏感性强于Q235钢，钢的强度对于应力腐蚀敏感性有一定的影响；点蚀的发生和酸性土壤环境促进了应力腐蚀的发生，其应力腐蚀过程主要受阳极溶解(Anodic dissolution, AD)控制，同时可能存在氢致开裂(Hydrogen induced cracking, HIC)的混合控制。

The stress corrosion cracking(SCC) behavior of U-bent specimens of Q235 and X70 steels buried in Singapore soil are investigated by observation of morphology involving pitting and cracking, analysis of corrosion products, as well as physical and chemical properties of soil, a preliminary study the corrosion behavior of X70 and Q235 steels made in China in a typical foreign soil environment. It is found that Singapore soil contains more sulfide bacteria, the sulfide bacteria reducing the damaging effects of sulfate reducing bacteria. Q235 and X70 steels are sensitive to SCC in acid soil environment of Singapore, the SCC susceptibility of X70 steel is higher than that of Q235 steel and the strength of steels affect the SCC susceptibility; pitting and acidity of soil promote the occurrence of SCC, the SCC process is mainly controlled by anodic dissolution(AD), while there also may by hybrid controlled by hydrogen induced cracking(HIC).