The Research on Erosion-Corrosion Behavior of B10 Copper-Nickel Alloy

摘要

Currently, B10 CuNi alloy has garnered widespread adoption in the maritime sector due to its robust corrosion resistance. Nevertheless, instances of corrosion rupture and p erforation persist in the elbow regions of shipboard ballast water, heat exchanger, and fire -fighting systems, highlighting the need for a comprehensive understanding of the intricate erosion -corrosion synergy in this alloy. The erosion - corrosion process i n B10 Cu -Ni alloy remains largely unexplored and necessitates further investigation. To this end, the present study delves into the disparities in erosion-corrosion behavior of B10 alloy exposed to a 3.5% NaCl solution containing sand particles for 36 hour s, utilizing a controlled loop apparatus to meticulously manipulate fluid temperature (36° C-37° C), flow velocity (0-4.5 m/s), and sand content (0-1%). Following the experimental exposure, sophisticated analytical tools such as scanning electron microscopy (SEM), X -ray photoelectron spectroscopy (XPS), surface profilometry, and electrochemical techniques were employed to meticulously examine the surface morphology, elemental distribution patterns, and compositional alterations within the film layers of the B 10 alloy. Our findings reveal the existence of a critical flow velocity range (2.5 -3.5 m/s) at a sand content of 1%, within which the protective surface film undergoes complete removal. Notably, at flow velocities exceeding 3.5 m/s, the corrosion film layer on the elbows of B10 copper-nickel alloy is comprehensively stripped away. Intriguingly, even at these high flow velocities, where no visible corrosion pits or extensive impact marks are discernible, a notable depletion of manganese (Mn) elements is obse rved. By synthesizing these findings, we have elucidated the erosion -corrosion damage mechanism of B10 copper -nickel alloy, contributing valuable insights into the development of enhanced protective measures and material design strategies for critical maritime applications.