CO_2和Cl^-共存条件下L245NB钢的腐蚀行为

Corrosion Behavior of L245NB Steel in the Presence of CO_2 and Cl^-

四川省油气田的天然气中都含有一定量的CO2,为此,借助静态高温高压试验和电感式点腐测试仪,研究了不同CO2分压和不同Cl-浓度条件下L245NB钢的腐蚀行为。结果表明,在试验范围内,随着CO2分压和水中Cl-浓度的升高,L245NB的腐蚀速率相应增大;在40℃、总压为9 MPa、CO2分压大于1.0MPa,以及Cl-浓度大于5%的试验条件下,气相出现了点蚀。最后,还考察了抗CO2腐蚀缓蚀剂CT2-17对L245NB的保护效果。

The corrosion behavior of L245NB steel in the presence of CO2 with various partial pressure and Cl with various concentrations was evaluated using indoor static coupon test in high-pressure autoclave and inductance-type spot-corrosion test.The protective action of CO2 corrosion inhibitor CT2-7 for the steel was examined.Results showed that the corrosion rate of the steel increased with increasing partial pressure of CO2 and concentration of Cl-in the aqueous solution.Besides,gas-phase pit occurred at a temperature of 40 ℃,Cl-concentration of over 5%,total pressure of 9.0 MPa,and CO2 partial pressure of over 1.0 MPa.