摘要
采用IMO(国际海事组织)《货油舱用耐蚀钢试验程序》规定的模拟货油舱内底板腐蚀试验方法,研究了组织为马氏体、贝氏体+铁素珠、珠光体+铁素体的低合金高强度船板钢在酸性氯离子环境下耐蚀性。试验结果显示显微组织对钢的耐蚀性有显著影响。马氏体试验钢具有组织单一、碳化物析出少、产物膜对基体的保护效果最好的特点,其平均腐蚀速率最低。复相的珠光体组织,其渗碳体有较高的电位,与铁素体组织存在相间电位差,从而促进了铁素体的腐蚀,其锈层完整性和保护效果较差,腐蚀速率最高。贝氏体+铁素体试验钢相对马氏体试验钢在组织单一性上较差,但相对于珠光体+铁素体试验钢,其富碳相较少且分布均匀,这些对其在货油舱内底板环境中的腐蚀微电池数量和程度产生影响,因而其耐蚀性介于马氏体钢和铁素体+珠光体钢之间。
Test methods for simulating inner bottom conditions of cargo oil tanks（COT） according to test procedures for Qualification of Corrosion Resistant Steel for Cargo Tanks in Crude Oil Tankers by IMO（International Maritime Organization）,was used to study the corrosion resistance in acidic chloride media of low alloy marine steels with the microstructure of martensite,bainite and ferrite,pearlite and ferrite.Martensitic steel has single microstructure and less carbide precipitation,and corrosion product films with excellent protective effect,making it the lowest average corrosion rate.Selective corrosion of pearlite was developed under acidic chloride media,which is resulted from the duplex structure of pearlite.Cementite had high corrosion potential compared to ferrite,and the obvious interphase potential difference between cementite and ferrite promoted the corrosion of ferrite,making the film broken and less protective.So its corrosion rate is the highest.Compared with martensitic steel,the oneness of the microstructure of bainite and ferrite steel was poorer,while it has less carbon rich phases that were uniformly distributed,compared with ferrite and pearlite steel.These factors directly decided the quantity and degree of minute corrosive cell.So corrosion resistance of bainite and ferrite steel was between martensitic steel and pearlite and ferrite steel.
出处
《物理测试》
CAS
2013年第3期14-17,共4页
Physics Examination and Testing
基金
国家科技支撑计划资助项目(编号2011BAE25B01)
关键词
低合金钢
酸性氯离子环境
显微组织
耐蚀性
low-alloy steel
acidic chloride media
microstructure
corrosion resistance
