石油测井仪器表面材料点蚀原因分析

摘要

High Cr alloy can inhibit CO2 corrosion effectively. But in actual practice, some logging instruments have pitting corrosion phenomenon on the material surface during the loggings; there is a serious phenomenon of perforation. Pitting phenomenon is mainly because the Cl-dig to deep. Cr(OH)3 can inhibit the Cl-enrichment and alleviate the pitting effectively. 17-4PH steel pitting corrosion phenomenon is probably Cr(OH)3 can reach the metal surface by anion, thereby etching substrate. Perforation may be because of corrosion product falling leaves the region, which formed a large cathode anode corrosion environment.%　　高Cr合金能够有效的抑制CO2腐蚀,但是在实际中,有些测井仪器在深井测井后表面材料出现点蚀现象,严重的有穿孔现象。点蚀现象主要是因为Cl-深挖造成,Cr(OH)3能够有效的抑制Cl-富集,能够有效的缓解点蚀现象,17-4PH钢出现点蚀现象的原因可能是FeCO3依然能够通过阴离子使其到达金属表面,从而腐蚀基体。穿孔可能是因为腐蚀产物膜脱落使得该区域形成大阴极小阳极的腐蚀环境而造成的。