材料期刊网

通过特殊设计的电子试片,分别利用电阻法(ER)和电化学方法对同一个X65管线钢试片在3.5％(质量分数)NaCl溶液中的腐蚀速率进行了50 d的在线监测,并将在线监测结果与失重法的测量结果进行了对比.结果表明:随着腐蚀的进行,逐渐生成的锈层对X65管线钢的腐蚀有良好的抑制作用,腐蚀速率在30 d后降至初始腐蚀速率的1/6;ER法测试时,测试初期由于试片表面不均匀腐蚀,导致其测量结果与失重法的测量结果存在较小的误差,在腐蚀进行20 d后,二者具有良好的一致性;电化学方法在测试初期与ER法和失重法具有较好的一致性,但随着内锈层的发展,腐蚀在进行30 d后,电化学方法的测试结果远高于试片真实的腐蚀速率,表明电化学方法不适用于海洋环境中的长期腐蚀监测.

Through a special design of electronic coupons,on-line monitoring of corrosion rate for the same coupon of X65 steel in 3.5％ (mass fraction) NaCl solution for 50 d was carried out by electrical resistance (ER) and electrochemical methods.The measurement results by on-line monitoring were compared with those monitored by weight-loss method.The results show that the rust layer had an excellent inhibition for the corrosion of X65 steel.The corrosion rate reduced to 1/6 of the initial corrosion rate after 30 days.The ER monitoring results had a measurement error at the beginning due to the nonuniform corrosion on the specimen surface.The corrosion rates measured by ER technique and weight-loss method had a good accordance after corrosion for 20 days.The corrosion rate measured by electrochemical methods agreed with the other two kinds of methods during the initial period.However,after corrosion for 30 days,the electrochemical measurement results were much higher than the real corrosion rate of the specimen.It means that electrochemical methods are not applicable for long term corrosion monitonng in ocean surroundings.