Wear Failure Analysis And Its Control Of CA6DF2L-30 Diesel Engine Flywheel By Experimental And Finite Element Method

Flywheel plays an important role in diesel engine although it has a simple structure form. As a driving link in friction clutch, it transfers power to the driven disk by friction, so it is subjected to wear failure.In the paper, the wear failure forms and wear mechanism of the CA6DF2L-30 diesel engine flywheel were analyzed experimentally. The chemical compositions, hardness, microstructure morphology of the nodular cast iron flywheel were investigated by means of spectra analysis, OM and SEM. The major wear failure forms, mechanisms and the factors affecting wear failure have been determined.In order to improve wear-resistance performance, two novel Fe-based powders were prepared by mechanical alloying. As the main constituent of the additives, these powders were filled into the flux-cored wire and claded on the surface of the flywheel material by TIG overlaying welding. The results have shown that the hardfacing is characterized by micro/nano composite microstructure. The composite microstructure is composed of Fe-based amorphous alloy matrix and dispersion strengthened micro / nano-crystalline particles. It is the composite cladding that can improve the wear-resistance performance and prolong the service life of the flywheel material.The strengthening role of the alloying elements such as B, Cr, C and Si is studied in the welding experiments. An composite microstructure reinforced with micron/nano-crystalline grains were obtained through appropriate heat treatment after welding. The composite microstructure can effectively improve the wear-resistance performance of the flywheel material. It is beneficial to the dry friction of the flywheel. In addition, the welding alloy components with different contents of carbide powder were studied. The effect of welding alloy components, welding and heat treatment process on the microstructure and mechanical properties of the composite coating are also analyzed. The optimal preparation conditions were given. The excellent mechanical properties and thermal fatigue properties of the coating were proved by experiment, and the wear -resistant mechanisms were discussed.Based on FEM and fatigue damage theory, dynamic simulation for flywheel working under different conditions were established by ANSYS, including idling and friction contact. The stress and strain fields were calculated out under the above-mentioned conditions. The relationship between the strain, stress and fatigue wear was analyzed. The calculation results are consistent with the experimental findings. Besides, bionic structure was proposed to optimize the surface structure of the flywheel by FEM. The above study has provided a theoretical basis for the structural optimization, maintenance and fatigue life analysis of the flywheel.Finally, based on experimental study and FEM theoretical analysis, effective measures and rationalization proposals were made to prevent premature wear failure of the flywheel.