Effects of Temperature on Fretting Corrosion Between Alloy 690TT and 405 Stainless Steel in Pure Water

In pressurized water reactor, fretting corrosion has become the main reason for the failure of 690TT heat exchanger tubes. The effect of temperature on the fretting corrosion behavior between 690TT tube and 405 stainless steel (SS) bar has been studied during 106 fretting cycles. The overall average coefficient of friction (COF) values descends with an increase in test temperature, while the width of worn scar becomes wider. The severest fretting corrosion happens when the test temperature is at 100 °C. The wear mechanism differs at different test temperatures, from adhesive wear at room temperature to abrasive wear and delamination at 100 °C, to abrasive wear at 200 °C. Deformation slips, high residual strain concentration, and micro-cracks are found which are disadvantageous for the further service performance of the tubes.