结垢指数和氯离子对碳钢腐蚀行为的分析.docx

亘宝王些盘堂亟±堂位监塞
摘要
本文采用失重法、极化曲线法、和XPS表面分析技术等方法研究了PSI值、***离予浓度、HEDP和锌盐对碳酸氢钙溶液中的碳钢腐蚀行为的影响;用静态阻垢法研究了HEDP等阻垢分散剂对不同PSI值的碳酸氢钙溶液的阻垢分散作用。、、5,O、,***~
a
一、失重法结果表明: ,即使不加任何缓蚀剂,溶液也有一定的缓
蚀作用。
二、极化曲线研究表明: ,且随着PSI的减
小,碳钢的腐蚀速度降低; ,碳钢的过钝化电位正移,致钝电流密度减小,钝化区
的电位范围变宽;
***离子浓度的增加而增大;
4.***离子能破坏碳钢表谣的沉积膜,加速碳钢的腐蚀;
***离子的不同PSI值的碳酸氢钙溶液中,HEDP和锌盐的加入使得碳钢的腐蚀速率减小,,其维钝电流密度变小i
,使得碳钢的腐蚀速率减小,但是减小的幅度并不
大;
,碳钢的腐蚀速率明显变小,说明HEDP和锌盐有明显的协同效应;
***离子浓度大大地破坏了HEDP、Zn2+和碳酸钙形成的膜。三、XPS表面分析技术研究表明: l。碳钢表面的保护膜主要是由Ca(1I)、C(Ⅳ)、一OH和02一组成,另外还
有少量的Fe;
篮璺
,0时,碳酸氢钙溶液能在碳钢表面形成一层碳酸钙保护膜,抑制了金属的腐蚀;
,
要由Ca(II)、C(Ⅳ)和O(1I)组成,但是表面膜中检测不到P; ”,
要由Ca(II)、C(IV)、O(II)和Zn(II)组成; ”和5ppmHEDP,
面形成的膜主要由ca(II)、C(IV)、O(II)、Zn(11)以及P组成,但P的存在形
式比较复杂,从微观上证明了HEDP和锌盐具有协同作用。四、静态阻垢实验表明: ,HEDP的阻垢效率不太理想:
。
关键词:碳酸钙结垢指数极化曲线腐蚀阻垢性能有机膦酸
II
匾夏至些太堂堑±堂焦途塞
ABSTRACT
The Iiteratures of corrosion inhibitor and scale index were corrosion behaviors of carbon steel in different PSI(Puckorius Scale Index)solution and/or chloride
were studied by weight loss,polarization curves and XPS surface analysis technology.
The effect off the corrosion ofhydroxyethyli—denediphosphonic acid(HEDP)and zinc salt
were also evaluated,and their scale inhibition were evaluated by static test.
result of weight loss experiment showed that the corrosion rate of carbon steel
can be decrease in the lower PSI solution.
result of polarization curves showed that:
(1)carbon steel in different PSI solution is a typical active-passivate metal,and the
anidic dissolution rate increased with the increase of PSI.;
(2)With the decrease of PSl,the transpassive potential is moved up positive,passive
currunt density is reduced and the