Geng Huang He

Research on the Application and Design of Special Tools of the Hydrogenated Cylindrical Shell

Both the heavy cutting process and the importance of the chip control are discussed. Through analyzing the characteristics of the rough machining of the hydrogenated cylindrical shell, both the structure and the material of the turning tool for rough machining are designed. To test and verify the feasibility study on them, the contrast experiment between the new-type turning tool and the reference substance in cutting the 2.25Cr-1Mo-0.25V steel which is the material of hydrogenated cylindrical shell is made, then the service life and the chip-breaking performance of the tool are compared. Finally, the technical reference to design the new-type turning tools is summarized.

Research on the Dynamic Mechanical Characteristics of the Tool Life in the Excessively Heavy-Duty Cutting Process

Basing the foundation on the cutting experiments of 2.25Cr-1Mo-0.25V steel which is the material of hydrogenated cylindrical shell, the dynamic mechanical characteristics of the excessively heavy-duty cutting were analyzed. Then through researching the influence that the dynamic mechanical characteristics had on tools failure in limited heavy-duty cutting process, and the model of dynamic shearing force in cutting area was established. However, the experimental results showed that the dynamic shear-flowing-stress in cutting area had great influence on tools fatigue, and the mainly damaged form of the heavy-duty cutting tool was shearing fracture. Analyzing the theory comprehensively, the critical condition of tools fracture which was under the terms of extreme loading had been established finally.

Research on the High-Efficiency and Energy-Saving Cutting of the Aero Engine Fan Blades

As the heart of the aircraft, aircraft engine is the decisive factors of aircraft performance. The turbofan engine technology is in the forward position of aero engine, and has become the main power of fighter and civil aircraft. In order to improve the processing efficiency of the aero engine fan blades, a high-efficiency and energy-saving technology was given to replace the traditional processing methods. The paper analyzed and researched the problems which appeared in the machining process of the aero-engine, and the high-efficiency and energy-saving methods was summarized which would become the technical guidance of high efficiency machining of the aero engine fan blades.

Research on the High-Efficiency Turning Tool for Rough Machining of Large Hydrogenated Cylindrical Shell Forging

The large hydrogenated cylindrical shell is an important part of petrochemical pressure vessels. From the macroscopic aspects, the influence that the surface defects of the large hydrogenated cylindrical shells forging blank has on the high efficiency machining was analyzed in the paper firstly. Then, through the chemical point of view, the new chemical components of the shells material were known, and the shells material physical properties were also dissected. The phenomenon of compatibility between the Co element which is in tools material and the siderophile element of the 2.25Cr-1Mo-0.25V steel which is the material of the large hydrogenated cylindrical shell was found. Therefore, the technical performance requirements of the heavy-duty turning tool which is to achieve the goal of high efficiency cutting were put forward. Through researching the chemical and the physical properties of the shell, the new high-efficiency turning tool was designed from the aspects of the tools material and the tools geometric structure. Finally, the comparative test between the new heavy-duty turning tool which was named XF8 and the YT5 tool which was being used in factory was made, and by way of comparing both the service life and the chip-breaking performance of XF8 with YT5s, the test results showed that the XF8 met the requirements of high-efficiency heavy-duty turning, and the feasibility of the tools design scheme was further verified.

Tool Life Evaluation Methods of Heavy Forging Hogging Machining Based on Image Processing Technology

In practical production, the evaluation method of tool life that heavy forging shell ring is in hogging machining compare the length of its processing surface in a single direction, the method considers neither the actual cutting distance of cutting tool, nor the impact times sustained by the cutting tool, this paper provides a new method of tool life evaluation based on image processing technology. Through collecting images of processing surface of the work-piece, which contains the different colors and brightness caused by processed and unprocessed, and image processing, analysis and calculation, the new method can accomplish the calculation about the effective cutting distance of cutting tool and the number of impact force about cutting tool, it will be more scientific and more reasonable evaluation method of tool life. Finally, one example is given. New method can be used to provide accurate evaluation of tool life and material machinability for the machining of large forgings.

Research on Machinability of the Shell Materials and Tools' Failure

Large cylindrical shell is a large diameter and thick wall tube part working in high temperature and high pressure environment. It is made of 2.25Cr-1Mo-0.25V high strength steel, whose machinability is special. The characteristics of cutting temperature and cutting force are researched in the cutting process by analyzing the machinability of 2.25Cr-1Mo-0.25V steel in this paper. And the main tool failure modes are analyzed in the cutting process, combining with empirical approach to compare tool failure modes under cutting different steels. The high efficiency cutting measures are proposed in tool optimization design finally, in order to provide a reference for high efficiency machining of large cylindrical materials.

Research on the Tools’ Life in the Dynamic Heavy-Duty Cutting Process

In this paper, the machinability of surface is introduced, and it is obtained from the analysis that the main macroscopic factors of tool premature failure are forging defects. Through research on the mechanism and rule of heavy-duty turning tool fracture failure, the conclusion is obtained that dynamic load leads to tool fracture and breakage finally. The tool working state under dynamic load is analyzed similarly by finite element software, and the simulate result verifies accuracy of the conclusion. Finally, the critical time model of tool fracture under dynamic load is established and the prevention measures of tool premature failure are formulated, which provide reference for the improvement of production efficiency and tool breakage prediction.

Research on the Tools' Strength in the Condition of Uncommonly Dynamic Heavy-Duty Loads

ntroducing the machining-ability of the surface of hydrogenated cylindrical shells blank, and the analysis showed that one of the main macroscopic factors which caused the tool to be broken early was forging defect. According to researching on both failure mechanisms and rules of the heavy-duty turning tools fracture, the conclusions that the dynamic load led into the crack then made the tool to be broken could be drawn. Then, the finite element simulation was utilized to analyze the tools working state under dynamic load condition, and the simulation results verified the correctness of the conclusion. For improving production efficiency and providing a reference for the prediction of tool breakage, finally, the critical time model of tool breakage under the condition of dynamic cutting was built, and the measures of preventing tools premature failure were developed.

The Design and Simulation of Main Tool Carrier System in a Condition of Large Vertical Lathe

To solve excessivly large deformation and vibration problems in machining large tube section, ensure the machining accuracy and quality of the tube section, the main tool carrier system of a large vertical lathe is designed, by simulation means of finite element, static analysis, dynamic modal analysis and dynamic response analysis are respectively carried on the main tool carrier structures designed. A reasonable overhang length of the tool in the tool carrier system is given through static analysis, dynamic modal analysis show the higher natural frequency of the tool carrier system, the production of cutting resonance can be avoided, the maximum response and corresponding stress conditions of the system under the harmonic loads are given by dynamic response analysis, analysis results show that the sustainable dynamic characteristics of tool carrier system can meet the machining requirements.

The Design and Finite Element Analysis of the Tool in Turning the Inner Ring Groove of a Large Cylindrical Shell

In this paper, for turning the inner ring groove of a large nuclear cylindrical shell, based on requirements of machining condition, the matching tool assembled are designed. Based on the platform of finite element simulation analysis, the deformation and stress analysis of the tools overall structures are carried out, this provides a theoretical basis for the static strength evaluation of the tools. Through the dynamics modal analysis of the tools, natural frequencies and modal shapes of the tools are obtained, this provides a theoretical basis to evaluate the dynamic characteristics of the tools, in particularly, the resonance characteristics. Through static and dynamic analysis, the reasonableness of structural design of the tools is evaluated theoretically.