Device and method for evaluating pitting corrosion resistance of stainless steel in 100-150 DEG C heat supply network system

Abstract

The invention discloses a device and method for evaluating pitting corrosion resistance of stainless steel in a 100-150 DEG C heat supply network system. The device comprises an electrochemical testing container, a concentrated liquid storage box and a reference electrode container; the electrochemical testing container is wrapped with a constant-temperature heating sleeve; the electrochemical test container is filled with heat supply network water simulation liquid; a stirring paddle is arranged at the bottom in the electrochemical testing container; a chloride ion concentration adjusting liquid adding opening is formed near the stirring paddle; a platinum sheet electrode, a stainless steel working electrode and a salt bridge are arranged on the electrochemical testing container; a salt bridge is bridged between the electrochemical test container and the reference electrode container; a NaCl solution is contained in the concentrated liquid box, and the concentrated liquid box is connected with the chloride ion concentration adjusting liquid adding opening through a pipeline; the other end of the salt bridge extends into a reference electrode container, a KCl solution is filled in the reference electrode container; a reference electrode is also arranged on the reference electrode container. The reference electrode and the test solution are separated by using the salt bridge, so that the reference electrode is used at normal temperature, and the test result is more stable.

Description

technical field [0001] The invention belongs to the field of research on material corrosion behavior in heating pipe network systems, and in particular relates to a device and method for evaluating the pitting corrosion resistance of stainless steel in heating network systems at 100°C to 150°C. Background technique [0002] The heating pipe network is an important equipment to ensure the heating of residents in winter, and the stable operation of the heating pipe network is of great significance to the protection of people's livelihood. The heat exchange tubes or heat exchange plates in the heating pipe network are usually made of stainless steel, and pitting corrosion is the main failure mode in this environment. The water volume of the heating pipe network system is large, and the water source for replenishment is usually complicated. Moreover, compared with the circulating water system, the temperature of the heating network system is higher, and the risk of pitting corr...

AI Technical Summary

Problems solved by technology

The pitting sensitivity of stainless steel under a certain chloride ion concentration can be analyzed by means of potentiodynamic polarization curve and constant potential test, but in order to find the critical value, it is often necessary to prepare solutions containing different concentrations of chloride ions and conduct multiple tests , gradually find the critical value, and the test takes a long time

At present, there is no relatively simple device and method for testing the critical chloride ion concentration of stainless steel pitting corrosion on the market

Images