APPLICATION OF STRAINING ELECTRODE TO HIGH TEMPERATURE CORROSION

摘要

A tensile stress test combined with an electrochemical polarization technique employing a 25 mol% K_2SO_4 - 25 mol% Na_2SO_4 - 50 mol% ZnSO_2 melt as an electrolyte, namely a high temperature straining electrode (HTSE) system, has been developed for study on high temperature corrosion. This system examined spalling and cracking characteristics of oxide films in situ on Type 304 stainless steel at 773 K. The stainless steel was polarized in a passive potential region in the molten sulfate mixture and the anodic current induced by spalling and cracking of oxide films during deformation at a constant strain rate was monitored. This system has been also applied to study of the characteristics of anodic dissolution and subsequent passivation in the molten sulfates that occur immediately after the mechanical breakdown of oxide films.