| Seawater is a kind of clean, nonflammable, widely available, and easy to store andtransport material, and is an ideal pressure medium in modern water hydraulicstechnology. However, seawater has lower viscosity and high vapor pressure than thehydraulic oil, which result in a series of tough problems such as serious corrosion,poor lubrication, prone to friction-wear and cavitation. Therefore, study on theseissues is not only helpful to make seawater hydraulic pumps, but can give someguidance to the development of other seawater hydraulic components.Based on the analysis of failure mode and mechanism of seawater pump, aconclusion can been draw that the corrosion resistance of materials and trobologicalbehaviors of the key friction pairs have a critical effect on the reliability of seawaterhydraulic pumps.The corrosion resistant properties of hydraulic pumps materials have beeninvestigated by seawater immersion and electrochemistry. The test results show thatthe material without heat treatment has preferable corrosion resistance but thecorrosion resistance of material with the surface or the whole heat treatment shows uppoorer corrosion resistance performance. For the common heat treatment of materialused in the seawater pump，solution and aging，low pressure nitrogen and nitrizinghave better corrosion resistance performance compared to others QPQ treatmentwhich has the worst corrosion resistance behavior.Focused on the wear failure of the seawater hydraulic pump, research groupintroduce MCF-10wear and friction test-rig to simulate the key friction pair slidingvelocity and stress distribution in seawater pump. It can be concluded from theanalysis results that the material has the lowest friction coefficient and wear rate valueat1m/s and load of2.66MPa. Compared with17-4PH/PEEK friction pair, thefriction pair composed of Ceramic/PEEK (Si3N4, SiC) and316L/PEEK have lowerfriction coefficient, and the value of friction coefficient are mainly less than0.04.In the light of the above comparative study of tribological characteristics, ceramicwas choosed as the slipper pad material to calculate anti-wear reliability. Ansys-PDSmodule was used to build modeling, calculate reliability and analyze the influence ofimport variable on output results. A new seawater hydraulic pum structural scheme with high reliability has beenproposed by analysis of hydraulic pump structural. The paper takes slipper pad asexample to deduce accelerated life test equation. |
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