Degradation of Armco iron caused by cavitation was analysed. Cavitation erosion tests were carried out in a cavitation tunnel with a system of barricade exciters at two conditions: inlet pressure of 1000 kPa and 1200 kPa, and outlet pressure of 125 kPa and 130 kPa, respectively. In each test, three adjacent samples were examined. The case with increased inlet pressure caused more than a 3-fold increase (3.75 times) in the mass loss of sample 1 – as placed closest to the barricade exciters during 20 min of testing. Mass losses observed in samples 2 and 3 were equivalent for each test condition. Hardness measurements showed that the increase in surface hardness (i.e. at a depth of 0.02 mm) occurred only in samples 1, while in samples 2 and 3 softening occurred (the decrease in hardness). For sample 1, higher inlet pressure caused over 5 times hardness increase. However, the greater hardening depth was observed at the lower inlet pressure test. Numerical simulation showed that the impact of water micro-jet with the velocity of 100 m/s exceeds the tensile strength of Armco iron, and produces a pit with the depth of 0.7 μm. The increase in impact velocity to 500 m/s increases a pit depth to 4.6 μm. The depth of pits observed in sample 1, which was tested at the inlet pressure of 1000 kPa, indicated that the impact velocity was up to 200 m/s. For tests conducted at 1200 kPa, the depth of an observed pit indicates a micro-jet impact velocity was estimated around 500 m/s.

分析了由空化引起的 Armco 铁的降解。在带有路障激励器系统的空化隧道中进行了空化侵蚀试验，条件为入口压力分别为 1000 kPa 和 1200 kPa，出口压力分别为 125 kPa 和 130 kPa。在每个测试中，检查三个相邻的样品。入口压力增加的情况导致样品 1 的质量损失增加了 3 倍以上（3.75 倍） - 在 20 分钟的测试期间最靠近路障激励器。对于每个测试条件，在样品 2 和 3 中观察到的质量损失是相同的。硬度测量表明，表面硬度的增加（即深度为 0.02 毫米）仅发生在样品 1 中，而在样品 2 和 3 中发生软化（硬度降低）。对于样本 1，更高的入口压力导致硬度增加 5 倍以上。然而，在较低的入口压力测试中观察到更大的硬化深度。数值模拟表明，速度为100 m / s的水微射流的冲击超过了Armco铁的抗拉强度，并产生了深度为0.7 μm的凹坑。冲击速度增加到 500 m/s 将凹坑深度增加到 4.6 μm。在1000 kPa入口压力下测试的样品1中观察到的凹坑深度表明冲击速度高达200 m / s。对于在 1200 kPa 下进行的测试，观察到的坑的深度表明微射流冲击速度估计约为 500 m/s。数值模拟表明，速度为100 m / s的水微射流的冲击超过了Armco铁的抗拉强度，并产生了深度为0.7 μm的凹坑。冲击速度增加到 500 m/s 将凹坑深度增加到 4.6 μm。在1000 kPa入口压力下测试的样品1中观察到的凹坑深度表明冲击速度高达200 m / s。对于在 1200 kPa 下进行的测试，观察到的坑的深度表明微射流冲击速度估计约为 500 m/s。数值模拟表明，速度为100 m / s的水微射流的冲击超过了Armco铁的抗拉强度，并产生了深度为0.7 μm的凹坑。冲击速度增加到 500 m/s 将凹坑深度增加到 4.6 μm。在1000 kPa入口压力下测试的样品1中观察到的凹坑深度表明冲击速度高达200 m / s。对于在 1200 kPa 下进行的测试，观察到的坑的深度表明微射流冲击速度估计约为 500 m/s。