摘要
对碳钢和Cr-Cu-Ni低合金钢进行模拟原油船货油舱上甲板环境的CO_2-O_2-H2S-SO_2干湿交替腐蚀实验,通过失重法获得模拟货油舱上甲板环境条件的腐蚀速率,分析锈层的物相组成并对带锈试样进行腐蚀电化学测试。结果表明,Cr-Cu-Ni低合金钢腐蚀初期减薄量大于碳钢,但随着腐蚀时间延长,Cr-Cu-Ni低合金钢腐蚀速率低于碳钢。相比于碳钢腐蚀电流密度降低幅度小的特点,Cr-Cu-Ni低合金钢腐蚀电流密度由裸钢的67.4μA/cm^2显著降低至带锈钢的11.7μA/cm^2。碳钢锈层内存在较大的贯穿整个锈层截面的裂纹,而Cr-Cu-Ni低合金钢中的耐蚀合金元素Cr Cu及Ni加入使锈层颗粒细小,结构致密,锈层内部截面裂纹细小。两种钢锈层均由非晶态腐蚀产物α-Fe OOH、少量的γ-Fe OOH、Fe_3O_4和单质S组成。相比碳钢的锈层,Cr-Cu-Ni低合金钢锈层具有较高的非晶态物质含量及较大α/γ值(α-Fe OOH与γ-Fe OOH含量比),从而使锈层具有高的致密度和保护性。
Corrosion behavior of carbon steel and Cr-Cu-Ni low alloy steel with rust forming in simulated CO 2-O 2-H 2 S-SO 2 wet-dry environment of cargo oil tanks of crude oil tankers for 98 days were investigated using corrosion rate by mass loss method,scanning electron microscope,X-ray diffraction,and electrochemical measurement.The results showed that the corrosion rate of Cr-Cu-Ni low alloy steel was higher than carbon steel in initial period,while with the increase of corrosion time,it tended to be lower than carbon steel.The corrosion current density of Cr-Cu-Ni low alloy steel reduced greatly from 67.4μA/cm 2 to 11.7μA/cm 2 after a period of corrosion,while the corrosion current density of carbon steel decreased little.The rust layer of carbon steel contained large cracks throughout the cross-section of it,while the rust of Cr-Cu-Ni low alloy steel was compact due to the small size of rust particles,with smaller cracks in cross-section of the rust.The rusts of both carbon steel and Cr-Cu-Ni low alloy steel were composed of amorphous corrosion products,α-FeOOH,small account ofγ-FeOOH,Fe 3 O 4 and element S.Compared to the rust of carbon steel,the rust of Cr-Cu-Ni low alloy steel had a high content of the amorphous corrosion product and a highα/γvalue(the content ratio ofα-FeOOH toγ-FeOOH),leading to high rust compactness.
作者
朱祎淳
柳伟
赵庆贺
赵永刚
张彬礼
李晓刚
ZHU Yichun;LIU Wei;ZHAO Qinghe;ZHAO Yonggang;ZHANG Binli;LI Xiaogang(Corrosion and Protection Center,Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China)
出处
《中国材料进展》
CAS
CSCD
北大核心
2018年第1期35-42,共8页
Materials China
基金
国家重点研发计划(2016YFE0203600)
国家自然科学基金项目(51571027)
关键词
低合金钢
合金元素
锈层
货油舱
low alloy steel
alloy elements
rust
cargo oil tank
