摘要
在青岛海洋大气环境中对3种不同表面状态的300M钢(裸材、低氢脆镀镉钛处理、超音速火焰喷涂WC-10Co4Cr)进行2 a大气暴晒实验,通过表面截面形貌观察、腐蚀产物分析等手段,研究了不同的表面处理方式对300M钢腐蚀行为的影响与机理。结果表明,经2 a大气暴晒后,超音速火焰喷涂WC-10Co4Cr的300M钢喷涂层发生剥落,基体作为阳极与喷涂层间发生电偶腐蚀及缝隙腐蚀,腐蚀速率最快,腐蚀坑最深;低氢脆镀镉钛处理的300M钢表面镀镉钛层腐蚀电位低于基体,镀层优先于基体发生腐蚀,因此对基体保护作用最好,腐蚀速率最低,腐蚀坑最浅。裸材与火焰喷涂层下的腐蚀产物主要由α-FeOOH、β-FeOOH、γ-FeOOH和Fe3O4组成,而镀镉钛试样表面除部分钢的腐蚀产物外还有Cd(OH)2和CdO2。镀镉钛层由于牺牲阳极作用保护效果最好,超音速火焰喷涂WC-10Co4Cr由于引发电偶腐蚀及缝隙腐蚀,加重了基材的腐蚀。
Atmospheric exposure of three types of 30 M steel with different surface treatments(bare material, Cd-Ti Plating of low hydrogen embrittlement, high-velocity oxygen-fuel(HVOF) sprayed WC-10Co4Cr coating) were conducted for 2a in Qingdao marine atmosphere. Then the corroded steels were characterized via surface and cross-section morphology observation and corrosion products analysis. The results of the two-year atmospheric exposure test are as follow: the HVOF sprayed WC-10Co4Cr coating peeled off, while galvanic corrosion and crevice corrosion occurred between the coating and the substrate which acted as anode, and the corrosion rate was the fastest and the corresponding corrosion pits were the deepest. While the corrosion potential of the Cd-Ti plated steel was lower than that of the substrate, and the plating was corroded prior to the substrate. The corrosion rate of the plated steel was the slowest and the corresponding corrosion pits were shallow, which indicated that the protective effect of Cd-Ti plating was the best among the three. The corrosion products on the bare steel as well as the substrate beneath the HVOF coating were mainly composed of α-FeOOH, β-FeOOH, γ-FeOOH and Fe3O4, but Cd(OH)2 and CdO2 were also appeared on the surface of the steel with Cd-Ti plating. The protective effect of Cd-Ti plating was obvious because of sacrificial anode protection, but the HOVF sprayed WC-10Cr4Cr caused galvanic corrosion and crevice corrosion, which aggravated the corrosion of the substrate.
作者
赵晋斌
赵起越
陈林恒
黄运华
程学群
李晓刚
ZHAO Jinbin;ZHAO Qiyue;CHEN Linheng;HUANG Yunhua;CHENG Xuequn;LI Xiaogang(Jiangsu Key Laboratory fo r Premium Steel Material,Nanjing Iron&Steel Co.,Ltd.,Nanjing 211500,China;Corrosion and Protection Center,University of Science and Technology Beijing,Beijing 100083,China)
出处
《中国腐蚀与防护学报》
CAS
CSCD
北大核心
2019年第6期504-510,共7页
Journal of Chinese Society For Corrosion and Protection
基金
国家自然科学基金(51971033)
国家重点研发计划(2016YFB0300604)
国家材料腐蚀与防护数据中心。
关键词
300M钢
低氢脆镀镉钛
超音速火焰喷涂
海洋大气腐蚀
300M steel
low hydrogen embrittlement Cd-Ti plating
high-velocity oxygen-fuel sprayed
marine atmospheric corrosion
