环境因素对X80钢焊接接头腐蚀电化学行为的影响

Effect of environment factors on corrosion electrochemical behavior of X80 steel welded joint

通过正交试验法,采用动电位极化技术研究溶解氧、温度、p H值等环境因素对X80管线钢焊接接头在库尔勒土壤环境中的腐蚀电化学特征的影响。结果表明:库尔勒土壤模拟溶液中溶解氧从0.5 mg/L增大到6.5 mg/L时,X80管线钢焊接接头的腐蚀程度越来越严重,当氧含量为6.5 mg/L时,试样的腐蚀电流密度达到59.237μA/cm2;环境温度从20℃上升到60℃,X80钢焊接接头的腐蚀程度明显加剧,当温度为60℃时,试样的腐蚀电流密度达到44.593μA/cm2;溶液p H值从7.0增大到11.0,X80钢焊接接头的腐蚀程度相对减弱,当p H值达到11.0时,试样的腐蚀电流密度达到31.417μA/cm2。溶解氧含量对X80钢焊接接头的腐蚀行为影响最大,其次p H值的影响,温度对试样的腐蚀性影响相对最小。

The effect of environment factors including the dissolved oxygen,temperature and p H value on corrosion behavior of X80 steel welded joint in simulated Ku＇erle soil solution was investigated by potentiodynamic polarization and orthogonal testing. The results show that with the increasing of oxygen content from 0. 5 mg / L to 6. 5 mg / L,the corrosion of X80 steel welded joint is more serious. When the oxygen content is 6. 5 mg / L,the corrosion current density of the sample is 59. 237 μA / cm2. With the increasing of temperature from 20 ℃ to60 ℃,the corrosion of X80 steel welded joint is significantly intensified. When the temperature is 60 ℃,the corrosion current density of the sample is 44. 593 μA / cm2. With the increasing of p H value from 7. 0 to 11. 0,the corrosion of X80 steel welded joint is weakening. When the p H value is 11. 0,the corrosion current density of the sample is 31. 417 μA / cm2. Corrosive influence of dissolved oxygen on the X80 steel welded joint is maximal,and the p H value is second,while the temperature corrosive effect on metal is relatively minimal.