The two cutting tools obtained from ultra-fine grade Ti (C,N)-based cermets were tested in the dry cutting of a medium carbon steel (AISI1045). Microstructure and mechanical properties were studied. Wear mechanisms (mainly diffusion and oxidation) were investigated in detail and compared each other in order to better understand key aspects due to thermal wear mechanisms. Comparing tool A with B, under the adopted cutting conditions, the tool A has a better resistance to oxidation deformation in machining medium carbon steel due to the higher hardness, although tool B has higher bending strength and fracture toughness.

Different process steps of the workpiece have different effects on the microstructure in the multi-stage forging. In this study, the effect of four different process steps of steering arm on microstructure was studied by FEM. Results have showed that upsetting is beneficial to refine the microstructure as well as finish forging. Especially drawing can make the distribution of microstructure homogeneous while bending has less effect on it. The already-designed forging process for steering arm was reasonable based on the simulation. Eventually, the grain size level of the steering arm was tested as 6.5 based on the conventional standard.

According to the structure features of the piston, the method of combining application of finite element simulation and theoretical analysis was explored to determine the extrusion process program and the extrusion process parameters. Theoretical calculation shows that a longitudinal extrusion and a lateral extrusion can form piston. The result comparing simulative prediction with theoretical calculation demonstrates that there is a good fit between the two and the theoretical calculation is right. The result of simulative prediction demonstrates that the grain size of piston after extrusion is about 17.8 μm and the refining rate reaches 55%. The grain size on both sides of the piston skirt and piston internal floor place is about 27 μm, so the refining effect is less obvious than other parts. However, the grain refinement in the piston pin holes is more obvious, the grain is refined to 13 μm and the refining rate is about 67.5%.The result comparing simulative prediction with the experimental analysis demonstrates that there is a good fit in grain refinement between the two.

The stability of mold oscillation can directly influence on slab surface quality and operational safety in continuous casting. In recent years, the hydraulic oscillation is developed and applied as the driven equipment of mold oscillation. In the present work, based on the slab continuous caster of hydraulic oscillations, the displacement and other parameters of hydraulic oscillator are measured and the evaluation method of oscillation is studied. The displacement difference and phase difference of oscillation with sinusoidal waveform and non-sinusoidal waveform are analyzed. Especially, the dynamic characteristics of the driving force of left and right cylinders are evaluated. The results indicated that the hydraulic oscillator is quite a good device in terms of precision. The method proposed may be useful for evaluating oscillators.

In order to get high quality forgings, it is significant to predict the microstructure evolution during hot forging process accurately. In this study, a simulation model is built by combining FEM with the dynamic recrystallization model of 42CrMo, and the finite element model is proved to be reliable by a serial of upsetting deformation experiment. Then the distributions of microstructure evolution are obtained on upsetting process. Upsetting is beneficial to refine the grain size and drawing can make the distribution of grain size homogeneous. By comparing the simulation results with experiments, the distributions of microstructure are a close match in the middle part of steering arm. The forgings formed by this process have a good microstructure and have high comprehensive mechanical properties.