Impact-sliding fretting tribocorrosion behavior of 316L stainless steel in solution with different halide concentrations

Abstract

Impact–sliding caused by random vibrations between tubes and supports can affect the operation of heat exchangers. In addition, a corrosive environment can cause damage, accelerating the synergism of corrosion and wear. Therefore, the focus of this work was the impact–sliding fretting tribocorrosion behavior of 316L heat exchanger tubes at different halide concentrations. A device system incorporating the in situ electrochemical measurements of impact–sliding fretting corrosion wear was constructed, and experiments on 316L heat exchanger tubes in sodium chloride (NaCl) solution with different concentrations (0.0, 0.1, 0.5, 1.0, 3.5, and 5.0 wt%) were carried out. The synergism between wear and corrosion was also calculated and analyzed. The wear and damage mechanisms were elucidated by correlating the corrosion–wear synergism, morphologies, and material loss rates. The results indicated that the stable wear stage occurred at approximately 9–12 h, after which the corrosion current increased with the expansion of the wear area. As the halide concentration increased, the scale of damage on the wear scars gradually decreased, changing from being dominated by cracks, delaminations, and grooves to being dominated by scratches, microgrooves, and holes. There was an obvious positive synergism between wear and corrosion. The material loss was dominated by pure mechanical wear and wear enhanced by corrosion, but corrosion enhanced by wear contributed more than tangential sliding fretting corrosion. The total mass loss increased gradually in the range of 0.0–0.5 wt% and decreased in the range of 0.5–5.0 wt%. Large-scale damage enhanced by corrosivity and small-scale damage reduced by lubricity dominated the material loss at low and high concentrations, respectively.

Effects of salt spray duration on the fretting corrosion behavior of the Inconel 690 alloy tubes

“…Before the fretting corrosion test, the OCP usually decreased with an increase in the salt spray duration [Figure 11(a)], indicating the increased corrosion sensitivity of the tube surface. An increase of the salt spray duration can increase the amount of Cl − ions adsorbed on the alloy surface, thereby affecting the integrity and stability of the passive film (Ma et al , 2023). The OCPs of all the treated samples were reduced after the fretting corrosion test [Figure 11(b)].…”

The effect of NaCl concentration on impact-sliding fretting corrosion behavior of Inconel 690TT heat transfer tubes

“…Tan et al (2021) studied the wear of 316L stainless steel in solutions with five different SO 4 - /Cl - ratios (from 0.31 M: 0 to 0:0.62 M), and found that the synergistic effect between wear and corrosion was the main factor causing material loss. Ma et al (2023) studied the impact-sliding fretting corrosion behavior of 316L stainless steel in solution with different halide concentrations, and found that the lubricity and corrosivity of the solution, respectively, dominated different concentration ranges.…”