Stainless steel is widely used in many industrial fields, and the requirements for its processing accuracy and surface quality are increasing. Stainless steel passivation processing has the advantages of no cutting force and the ability to process complex shapes, while mechanical processing can achieve high-precision dimensional control and good surface roughness. Combining the two to form a composite process can complement each other and give full play to their respective advantages. For example, in the manufacturing of aerospace parts, both high-precision dimensions and specific surface textures and performance are required, which are difficult to meet with a single process. Composite processes provide a feasible solution.
Determining the order of stainless steel passivation and mechanical processing is the key. Mechanical processing first can remove most of the excess and provide a more uniform excess distribution for electrolytic processing, which is conducive to improving the efficiency and stability of electrolytic processing. However, for some workpieces that are easy to deform or sensitive to surface residual stress, electrolytic processing of part of the excess first and then mechanical finishing can reduce the impact of processing stress on workpiece accuracy. For example, when processing stainless steel thin plate parts, electrolytic thinning first and then mechanical processing of the edge contour can effectively prevent the deformation of the thin plate.
In the composite process, the current density and electrolyte concentration of electrolytic machining and the cutting speed and feed rate of mechanical machining need to be coordinated and regulated. The appropriate current density and cutting speed can ensure the machining efficiency while obtaining the ideal surface quality. For example, in the rough machining stage, a higher current density and cutting speed are used to quickly remove the excess; in the fine machining stage, the current density is reduced and the cutting parameters are adjusted to refine the surface texture. At the same time, the effect of the electrolyte on the mechanical machining tool should be considered, and the tool material with good corrosion resistance should be selected and the tool geometry parameters should be optimized.
The composite process has a complex effect on the surface integrity of stainless steel. There may be micro-roughness and oxide layer on the surface after electrolytic machining. The cutting parameters should be reasonably selected during mechanical machining to remove these defects and avoid new damage. By controlling the cutting depth and tool sharpness of mechanical machining, the generation of surface residual stress and micro-cracks can be reduced. For example, a cutting method with a small cutting depth and a large feed, combined with appropriate electrolytic polishing parameters, can obtain a high-quality surface with low surface roughness and no work hardening.
The realization of the composite process of stainless steel passivation and mechanical machining requires special equipment integration. Combine the electrolytic processing device with the CNC machine tool, develop a unified control system, and realize the automatic adjustment of process parameters and the automation of the processing process. For example, the current, voltage, cutting force and other parameters in the processing process are monitored in real time by sensors, and the feedback is given to the control system to automatically optimize the processing parameters, improve the processing accuracy and stability, and reduce the influence of human factors.
Establishing a complete quality inspection and evaluation system is crucial for composite processes. The surface morphology, microstructure and dimensional accuracy of the processed stainless steel are inspected by using equipment such as surface roughness meter, profilometer, metallographic microscope, etc. According to the test results, the rationality of the process parameters is analyzed, and the process is adjusted and optimized in time to ensure that the product quality meets the requirements. For example, by comparing the surface roughness data under different process parameters, the best parameter combination is determined to achieve high-quality stainless steel composite processing.
The composite process combining stainless steel passivation with mechanical processing has broad application prospects in the field of high-end manufacturing. With the development of intelligent manufacturing technology, composite processes will develop in the direction of intelligence, high precision and high efficiency. For example, artificial intelligence algorithms are used to optimize process parameters and achieve adaptive processing; new electrolytes and tool materials are developed to further improve processing performance and meet the growing demand for stainless steel parts in industries such as aerospace, medical equipment, and new energy.
