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利用磁致伸缩空蚀试验机研究了ZQAl9-4-4-2镍铝青铜在2.4%NaCl溶液中的空蚀行为.结果表明:空蚀使ZQAl9-4-4-2镍铝青铜的自腐蚀电位正移约16 mV,使电化学腐蚀速率增大8倍;2.4%NaCl溶液中空蚀最大失重率是蒸馏水中的2.1倍.在腐蚀与空蚀的交互作用中,力学因素起了至关重要的作用,纯空蚀失重分量占总失重量57.3%,腐蚀因素作用相对较小.微裂纹首先在α/κ相界的α相部分形成;随着空蚀的进行,这些微裂纹在α相内合并扩展导致α相出现失重,κ相也随之剥离基体.空蚀微裂纹易于横向扩展而向深度方向受阻.试样表面均匀剥落,未出现大的海绵状的空蚀坑.ZQAl9-4-4-2镍铝青铜较好的加工硬化能力,是其具有良好的抗空蚀性能的关键所在.
The cavitation erosion behavior of ZQAl9-4-4-2 nickel-aluminum bronze in 2.4% NaCl solution was studied by using a magnetostrictive cavitation tester. The results show that cavitation causes self-corrosion of ZQAl9-4-4-2 nickel-aluminum bronze The potential shift is about 16 mV, which increases the electrochemical corrosion rate by 8 times. The maximum rate of cavitation loss in 2.4% NaCl solution is 2.1 times of that in distilled water. Mechanics play a crucial role in the interaction between corrosion and cavitation , The weight loss of pure cavitation accounts for 57.3% of total weight loss, and the effect of corrosion factor is relatively small.Microcracks first form in the α phase of α / κ phase boundary. With the cavitation erosion, In the combined phase, the α phase appears weightlessness, and the κ phase also peels off the matrix. The cavitation microcracks are easy to expand laterally and are blocked in the depth direction.The sample surface is spalled evenly, and no large sponge-like cavitation pits are found.ZQAl9-4 -4-2 nickel aluminum bronze better work hardening ability, it is the key to good anti-cavitation performance.