Local Corrosion of the Tube Still for Coolers Made of 18-10 Grade Steel in the Circulating Water of Petroleum Refineries

摘要

Corrosion-electrochemical behavior of tube stills of a 18-10 steel combined with the case component members from plain carbon steels in circulating water of petroleum refineries is investigated. It was ascertained that the reasons for accelerated corrosion of tube panels, as well as origination and development of pitting corrosion perforating the bundle tubes, are as follows: a high content of chlorine ions in the circulating water and its periodical acidification; the contact between the two highly different steels accepted when manufacturing the coolers; and precipitation of corrosion products on the inner surface of tubes during shutdowns of the process.