裂解装置黄油抑制剂注入管线失效原因

Causes of Failure of Grease Inhibitor Injection Line in Cracking Unit

由于碳钢管在黄油抑制剂与碱液中的电位差达400mV,因此碳钢管在这两种溶液中产生强烈电化学腐蚀,在承受超载的外力下断裂失效。由此可见,抑制剂注入管线设计选材有误。将碳钢管改为1Cr18Ni9Ti不锈钢管后,运行至今再未发现腐蚀。

The electric potential difference of carbon steel pipe in grease inhibitor and caustic liquid was as great as 400 mV, and carbon steel pipe, which was subject to serious electro-chemical corrosion in these two solutions, failed under the external load. It can also be seen from this that the improper pipe material has been selected for the service. When the metallurgy of the pipe has been changed from carbon steel to 1Cr18Ni9Ti, the unit has been running without any corrosion.