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Since the 21st century, the development of automotive and home appliance industries has greatly contributed to the prosperity of the plastics industry, which has led to an increasing demand for molding molds. In the production process, the molds will be impacted, worn and corroded, especially in the production of plastic products made of PVC, fluoroplastics and flame retardant ABS, etc. The molds will be corroded by the corrosive gases generated such as hydrogen chloride, hydrogen fluoride and sulfur dioxide, which requires plastic molds to have a certain degree of corrosion resistance while ensuring strong toughness.S136 SUP is a modified martensitic stainless steel based on S136 from ASSAB, Sweden, which has fine-tuned the content ratio of some elements to ensure a certain strength and high toughness at the same time. The chemical composition, heat treatment and microstructure of the steel have a certain influence on its corrosion resistance, and the tempering temperature of the heat treatment has a greater influence on the corrosion resistance of martensitic stainless steel. Therefore, in this paper, the microstructure and corrosion resistance of S136 SUP at different tempering temperatures are explored and studied.

Laser shock processing is a new kind of technology to improve the physical and mechanical properties of the metal surface. It uses the high-amplitude stress wave produced by the interaction of short-pulse laser and material, to make the material produce the compressive residual stress and refinement internal structure, and lead to the improved hardness and strength of material. In this paper, the simulation of laser shocking process with square spot of Titanium alloy plate was carried out through ABAQUS. The influences of the shock time, laser energy, plate thickness and spot size on the strengthening are investigated from the view of residual stress. The results show that: There are the compression residual stress in the workpiece surface after laser shcok processing, and its amplitude is about 300-400Mpa. With the increase of shock time, the surface residual stress increases, the area and depth of strengthening zone also increase. The strengthening area becomes a circular, while the distribution of residual stress becomes unhomogeneous. The surface residual stress increases as the laser energy increasing, but the amplitude is smaller. The plate thickness does not affect the amplitude of the surface residual stress. When the shock pressure is constant, surface residual stress does not change with the spot size. However, if the laser energy is constant, due to the shock pressure will decrease with the increase of spot size. Therefore, there should be an optimized spot size when the strengthening effectiveness and efficiency are both considered.

The research of the simulation for high speed cutting is usually based on 2D modeling by now, and the 3D simulation is few. Because the cutting process is a 3D deformation of workpiece, it's badly in need of the research on 3D finite element simulation of cutting process for further reveal the mechanism of high speed cutting. The 3D simulation of inclined cutting of hardened 45 steel (45HRC) is carried out base on ABAQUS. The forming process of serrated chip is simulated by adopting the Johnson-cook material modeling and separation criterion of shear failure. The change of chip morphology, chip flow angle and deformation coefficient of width under different rake angle and cutting depth are analyzed. The results show that the segment degree of chip becomes larger with the decrease of rake angle and increase of cutting depth. The chip flow angle is not effected by rake angle and its value is approximately equal to tool cutting edge inclination angle, an it increases with the increase of cutting depth. The deformation coefficient of width increase with the decrease of rake angle and increase of cutting depth.

A method for building the constitutive relationship based on the J-C model and hardness is presented through considering the influence of hardness on the yield strength and the tensile strength. A constitutive relationship of hardened AISI 1045 is built by this method and the adiabatic shear critical cutting conditions of three kinds of hardness AISI 1045 steel are prediction through a model building by the linear pertubation analysis which considering the influence of compression stress of the primary shear zone, the cutting conditions and the constitutive relationship. For proving the prediction results, some orthogonal cutting experiments are performed to get the critical cutting conditions of adiabatic shear. The comparison shows that the prediction results are consistent with that of experiments.

A model is presented for the prediction of critical cutting conditions of adiabatic shear in orthogonal high speed cutting. Considering the influence of compression stress, a critical criterion of adiabatic shear in orthogonal high speed cutting is given by linear perturbation on the compress-shear deformation continuum mechanics basic equations of the primary shear zone. Combining with the relationship of cutting conditions and deformation ones, also the materials constitutive realtionship, a pridiction model, which expressed by cutting conditions and materials properties is established. As an example, the adiabatic shear critical conditions of AISI 1045 steel are predicted, and cutting experiments are performed. The prediction results are consistent with that of experiments.

A strategy of toolpath generation based on Tool-Zmap geometric model has been proposed to achieve efficient finish machining of mold cavity. Considering cutting tool wear, the finish machining of mold cavity was performed using variable cutting tools of different diameter. Each cutting tool only cuts the corresponding area to avoid identifying machining characteristic and poor rigidity of cutting tool during high speed machining. Finally, the validity of presented strategy was experimentally affirmed by a machining example.

Sculpture surface machining is a critical process commonly used in die/mold industries. Since there is a lack of scientific tools in practical process planning stages, feedrates for CNC machining are set individual constant values all along the toolpath. In this paper, an enhanced mathematical cutting force model is presented and is used for selecting varying and ‘appropriate’ feed values along the tool path in order to decrease the cycle time in sculpture surface machining. The model is tested under various machining conditions and proved to be effective.

The metallurgical observations of microstructure characteristics of the adiabatic shear bands(ASB) within the primary shear zones of the serrated chips produced during high speed machining high strength steel have been performed by using optical microscope, SEM and TEM. The observations showed that the microstructure between the matrix and the center of the ASB gradually was changed, the fine equiaxed grains appeared with size of about 0.4～0.6μm in the center of the adiabatic shear band. The serrated chip formation was likely due to material softening that occurred in the primary shear zones. The microstructural development of dynamic recovery and rotational dynamic recrystallization is the dominant metallurgical process leading to material softening in primary shear zone during high speed machining. A model of microstructural development in primary shear zone during serrated chip formation in high speed machining was suggested by analyzing material softening mechanism.