磷酸酯和磷酸盐在盐水泥浆中对碳钢的缓蚀作用

THE INHIBITION OF STEEL CORROSION IN SALT WATER DRILLING FLUIDS BY PHOSPHATE ESTERS AND SALTS

本文较系统地研究了磷酸酯和磷酸盐在盐水泥浆中对碳钢的缓蚀作用。应用滚轮失重法研究表明,当缓蚀剂使用浓度为1000ppm 时,缓蚀效率均在80%以上。发现 W-201磷酸酯能提高低固相泥浆的常温流变性能。电化学研究说明 NH_4H_2PO_4和 W-201属于混合型沉积膜型缓蚀剂。介质中的二价阳离子是影响缓蚀效果的重要因素。

The corrosion inhibition of steel in salt(NaCl)containing water-base drilling muds by a series of phosphate esters and two acidic salts of phosphoric acid(K_2HPO_4 and NH_4H_2PO_4) is studied.The results of experiments with tumbling-loss method show that most of these inhibitors in concentration of 1000ppm in muds provide no less than 80% protection to steel samples.Moreover,one of the phosphate esters,W-201,has improved the rheological be- havior of a low solid-phase mud at room temperature.On the basis of electrochemical stu- dies it is established that W-201 and NH_4H_2PO_4 being able to form a deposite film on the metal surface,belong to inhihitors of mixed control type,that is,they inhibit both ionic and cationic processes.The concentration of bivalent cations in the systems is a major factor influencing the efficiency of these phosphate inhibitors.