无阴极保护燃气管道腐蚀危害的表征参量及规律

Characterization Parameters and Laws of Corrosion Hazard of Gas Pipeline without Cathodic Protection

对某燃气公司2016~2020年间泄漏燃气管道的管地电位分布情况进行了统计分析,同时开展了现场腐蚀检查片埋设试验,获得了检查片腐蚀速率数据及对应的检查片通电电位、电流密度、通断电电位差、环境电阻率、地表电位梯度等5个参量,通过数据分析得出各参量与腐蚀速率的相关性及相关规律。结果表明,电流密度与管道腐蚀速率的相关性最好,皮尔逊系数高达0.95,在没有检查片的条件下,可以采用管地电位指标对管道的腐蚀风险进行评判。

A statistical analysis was conducted on the distribution of pipeline ground potential of a leaking gas pipeline in a certain gas company from 2016 to 2020.At the same time,on-site corrosion inspection piece embedding tests were conducted,and corrosion rate data of the inspection piece and corresponding 5 parameters such as the on/off potential,current density,on/off potential difference,environmental resistivity,and surface potential gradient of the inspection piece were obtained.Through data analysis,the correlation and related laws between each parameter and corrosion rate were obtained.The results showed that the correlation between current density and pipeline corrosion rate was the best,with a Pearson coefficient up to 0.95.Without inspection plates,the pipeline to ground potential index could be used to evaluate the corrosion risk of pipelines.