摘要
目的研究船舶低合金钢在模拟南海到北极的航行过程中的腐蚀情况,探索它在环境交变条件下的腐蚀行为与机理。方法选用3种温度(37、25、4℃)及相对应的典型海洋细菌,包括大西洋假交替单胞菌(Pseudoalteromonas atlantica)、需钠弧菌(Vibrio natriegens)和养料嗜冷杆菌(Psychrobacter cibarius),模拟航行往返过程中海洋环境的变化情况,以21 d为一个实验周期,每7 d改变一次温度和细菌种类,采用扫描电镜(SEM)、白光干涉、失重法和电化学测试方法从宏观和微观两方面对材料的腐蚀行为进行表征分析。同时,将相同的低合金钢试样浸泡在无菌海水中进行对照实验。结果浸泡在无菌海水中,当初始温度为37℃时,低合金钢的初始腐蚀速率较大;随着温度的降低和时间的延长腐蚀速率逐渐减小;当初始温度为4℃时,低合金钢的点蚀情况较严重,但腐蚀速率变化不大。浸泡在有菌海水中,初始温度为37℃时,低合金试样表面有大量方解石结构的碳酸钙镁盐沉积,从而较好地抑制了均匀腐蚀和点蚀的发生;当初始温度为4℃时,低合金钢试样表面点蚀严重,EDS能谱分析证明低合金钢试样在低温环境中没有明显的碳酸钙镁盐沉积。结论初始海水温度和细菌种类的不同会造成船用低合金钢腐蚀行为的极大差异,其原因主要是高温下细菌会诱导产生碳酸钙镁盐,并在低合金钢试样表面沉积,从而明显抑制了腐蚀;在低温环境下,细菌难以诱导碳酸钙镁盐的沉积,试样的均匀腐蚀和点蚀会非常严重,一旦发生腐蚀,即便后期再形成矿化产物膜也难以起到良好的防护作用。
This study aims to investigate the corrosion of low alloy steel during the simulated voyage from the South China Sea to the North Pole,and to explore the corrosion mechanism under the alternating environmental conditions.Three temperatures(37℃,25℃,4℃)and corresponding typical marine bacteria were selected,including Pseudoalteromonas atlantica,Vibrio natriegens and Psychrobacter cibarius.The change of Marine alternating environment during voyage and round trip was simulated.The experiment cycle was 21 days,and the temperature and bacteria species were changed every 7 days.Scanning electron microscopy(SEM),a three-dimensional(3D)optical profilometer,weight loss method and electrochemical test methods were used to characterize and analyze the corrosion behavior of materials from both macro and micro aspects.Meanwhile,the same low alloy steel samples were immersed in sterile seawater for the control experiment.In abiotic seawater,from 37℃to 4℃,the corrosion rate of low alloy steel decreased significantly.From 4℃to 37℃,the pitting corrosion of low alloy steel is more serious,but the corrosion rate changed inapparently.In the biotic seawater,from 37℃to 4℃,a large amount of calcium carbonate and magnesium salt were deposited on the surface of the low-alloy sample,thereby inhibiting the uniform and pitting corrosion significantly.However,from 4℃to 37℃,the surface of the low-alloy steel sample showed serious corrosion,and serious pitting corrosion was found after removing the corrosion products.X-ray energy dispersive spectroscopy(EDS)proved that the calcium and magnesium carbonates were not deposited on the steel surfaces under low-temperature environment.Therefore,the difference of initial seawater temperature and bacteria species can cause great difference in the corrosion behavior of marine low-alloy steel.The main reason is that bacteria can induce the deposition of calcium and magnesium carbonate on the surface of low-alloy steel samples at high temperature,which can obviously inhibit the corro
作者
毛晓敏
刘涛
郭娜
郭章伟
董丽华
MAO Xiao-min;LIU Tao;GUO Na;GUO Zhang-wei;DONG Li-hua(Shanghai Maritime University,Shanghai 201306,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2022年第6期36-47,共12页
Surface Technology
基金
国家自然科学基金(41976039,42006039,51901127)
上海市自然科学基金(19ZR1422100)。
关键词
微生物腐蚀
低合金钢
点蚀
生物矿化
环境交变
microbiological corrosion
low alloy steel
pitting corrosion
biomineralization
the alternating environment
