Study on electrochemical machining of involute internal spline of Cr-Co-Mo-Ni high-hardness gear steel.

Cr-Co-Mo-Ni high-hardness steel is widely used in critical mechanical transmission components. It has the difficult-to-cut characteristic because of its high hardness and high strength. In the cutting process, the machining cutting force is large, the tool is worn quickly, and the machining accuracy is poorly maintained. It has become one of the crux of restricting the improvement of quality and production efficiency of innovative products. In order to solve the above problems, this paper carried out research on the electrochemical machining process to achieve high-quality and efficient machining of high-hardness gear steel splines. Firstly, the process characteristics of ECM of internal spline are analyzed. The electrochemical field model is established by the multi-physical field coupling simulation platform, and the effects of the main electrolytic process parameters on the forming accuracy were numerically simulated and analyzed. Meanwhile, the three-dimensional simulation model of electrolyte flow field in the inner cavity of the electrolytic fixture is established, and the influence of electrolyte flow direction and electrolyte back pressure on the flow field distribution is explored. The platform of electrochemical machining system is set up. An experimental study on electrochemical machining of involute internal splines is carried out to further optimize the electrochemical machining process parameters. The test results showed that the electrolysis accuracy and efficiency of the 41-tooth involute spline workpiece are optimized when the electrolyte is 8% NaNO₃, the back pressure of the electrolyte is 0.2 MPa, the feed speed is 1.8 mm/min, and the processing voltage is 16.0 V. The machining accuracy of the method proposed in this paper meets the actual requirements of actual gear application. Compared with the traditional slotting process, the machining efficiency is improved by 62.5%, the tool wear is reduced, and the machining accuracy retention is improved. It has important application value for advanced machining technology of high-performance materials. [ABSTRACT FROM AUTHOR]