热处理后的X80管线钢在土壤模拟液中的腐蚀行为研究

Research on the Corrosion Behaviour of X80 Steel with Heat Treatment in Simulative Soil Solution

以21世纪天然气输送管线的首选钢-X80钢为例,利用失重法及电化学测试系统分析其在榆林定边和湖北黄冈地区的两种酸碱性土壤模拟溶液中的腐蚀情况,通过对正火态和调质态的X80钢在土壤模拟溶液中腐蚀情况进行研究,失重试验表明该钢在榆林定边地区腐蚀速率高于湖北黄冈地区的腐蚀速率,但差别比较小;两种不同组织X80钢的腐蚀速度都是由快到慢,最后趋于平稳;无论酸碱土壤,调质后的X80钢的腐蚀速度偏小。电化学测试表明两种不同组织的X80钢在酸碱土壤模拟溶液中都只有活性溶解,没有钝化倾向;调质态X80钢的自腐蚀电位偏负,腐蚀电流密度较小,导致其在两种模拟溶液中的腐蚀倾向大,腐蚀速率小。

X80 steel, which is also the first choice for natural gas pipeline in twenty-first Century.Analyzing the corrosion of X80 steel by using weight loss method and electrochemical measurementsystem in the simulated solution of soil which were from Huang Gang, Hu Bei and Ding Bian, Yu Linarea. The Corrosion characteristics of Normalized and quenched-tempered X80 in the two simulatedsolution were studied. The loss weight test showed that the corrosion rate of Ding Bian area was higherthan that of Huang Gang, but the difference is relatively small; the corrosion rate of two different tissuesof X80 steel in different area’s simulated soil solution are both from slow to fast, finally become stable.What ever in acidic or alkaline soils, the corrosion rate of quenched and tempered X80 steel is alsosmaller. The electrochemical test revealed that both the X80 steel with different microstructure occursactive dissolve without passivation in these simulated solution, the higher corrosion tendency and lowercorrosion rate of quenched and tempered X80 steel is due to the negative corrosion potential and smallercorrosion current.