Advanced Materials Research Vols. 631-632

Abstract: As to laser welding process of thin plate, the configuration style of welding deformation under constraint condition is investigated by designing two cases: (1) the free bead welding, (2) the bead welding with a constraint clamp. Both experiment and simulation for these two cases are carried out to study the corresponding phenomena of welding deformation. In numerical simulation, an equivalent method, i.e., the Local Equivalent Welding Element (LEWE), is used to predict the residual deformation of welding plate, which possesses higher efficiency and accuracy. Research results show that the constraint condition will remarkably affect the residual deformation behavior of welded plate.

Abstract: In order to ensure H-beam’s organization and performance requirements, there is a certain compression ratio from the rolling of the billet to the finished product. This paper select rectangular billets and use DEFORM finite element software to simulate and analyze the rules of stress variation when rectangular billet is cogged down. The simulation results show that: from rectangular billet to finished product, the compression ratio is 17.4 and after cogging, billet size meet the requirements of the CCS rolling. The equivalent stress of breakdown rolling is mainly concentrated in the waist or in the junction of waist and legs. In the first few pass，equivalent stress is mainly concentrated in Sharp-angled position of both top and bottom, however the next few pass’s equivalent stress is mainly concentrated in the junction of web Plate and flange.

Abstract: The microstructures have been investigated in steel plates with different rolling processes to find the reasons of yield ratio overseted standard in few high strength building steel plates produced in Echeng Iron and Steel Corporation. The effects of rolling path, rolling path depress ratio on microstructure and properties. Some reasons of yield ratio overseted standard have been analyzed. The results show that decreasing rolling paths and increasing depress ratio refined grains but unchanged area ratio and interlamellar spacing of pearlite. Yield strength excessively increased but tensile strength unchanged increased yield ratio. So, excellent properties can be obtained by applying the optimization process.

Abstract: It’s not easy to control the processing route of alien solid wooden furniture’s process, which is based on the CNC processing center. And the edition of the cutting tool path is complex. This paper puts forward the optimization design method of section layout, and determines the method of the cutting tool path through choosing proper cutting tool and adjusting the parameters. This paper also verifies the effectiveness of this method, taking a head of Europe type bed processing line as an example.

Abstract: A suitable match of annealing process parameters is critical for obtaining the fine microstructure of material. Low carbon low alloy steel (20CrMnTi) was heated for various durations near Ac temperature to achieve fine pearlite and ferrite grains. Annealing temperature and time were used as independent variables, and material property data were acquired by orthogonal experiment under intercritical annealing followed by subcritical annealing process (IASAP). The weights of plasticity (hardness, yield strength, section shrinkage, and elongation) of annealing material were calculated by analytic hierarchy process, and then the process parameters were optimized by using the grey theory system. The results observed by SEM images show that the optimized material microstructure consists of refining and distributing uniformly ferrite-pearlite grains, and smaller lamellar cementites. Morphologies on tension fracture surface of the optimized material indicates that the numbers of dimple fracture show more finer toughness obviously comparing with other annealing materials. Moreover, the yield strength value of the optimized material decreases apparently measured by tensile test. Thus, the new optimized strategy is accurate and feasible.

Abstract: In order to enhance the efficiency and the surface smooth degree of the RBSiC grinding, a three factors two levels full factorial design was utilized to optimize the process. Combined with the effects of grinding parameters on surface roughness, the grit cut depth analysis was employed to choose the appropriate grinding parameters. The strength reliability and the residual stresses of the RBSiC ground using the optimized parameters were investigated. The results show that comparing to the polished RBSiC the ground ones have higher compressive residual stress, lower crack scatter and similar average bending strength.

Abstract: In this paper, ultra-high strength dual phase steel was investigated. Thermomechanical processing was conducted by using a laboratory hot rolling mill. The results have shown that the main transformation products at three different kinds of thermomechanical processing were ferrite, bainite, and small amounts of martensite. Laminar cooling led to ferrite grain refinement. The mechanical properties of specimen 1 which was controlled cooling after a relative lower temperature rolling are much higher than that of specimen 2. The presence of martensite islands and precipitates contributed to the enhancement of strength of the present steel. And the presence of retained austenite resulted in higher toughness. As a result, these specimens exhibited satisfactory mechanical properties.

Abstract: In order to meet the needs of recovery production of filtering and washing of fine powder of rare metal, a device has been developed which is a set ultra-fine filter, mixing washing, dry-pressed cake, cake discharge and microporous regeneration, etc. in one integral device, and all steps can be completed once using it in a confined space. In addition, a number of key technologies were advanced that can be realized by the device, including recycling technologies, polymer ultra-fine filter technology, equipment and structural design, workflow design, etc. The device has many advantages, such as high filtration precision, high recovery rate, high efficiency production, simple operation, high degree of automation and less environmental pollution. Fine powder of rare metal is generally prepared by electrochemical or chemical production method, wherein filtering and washing are two important processes. Filtering, washing, recovery technology and equipment progressiveness have a direct impact on products quality, resources loss, energy consumption, costs, environment and other problems. Design of a new ultra-precision filtering and washing equipment of fine powder of rare metal and its advanced recycling technology are of great significance.

Abstract: In order to obtain cover and pump body of tin bronze Tonghai pump that is dense and good pressure resistance,the casting mold of the cover of Tonghai pump is metal mold. The casting method of Tonghai pump is vacuum counter-pressure casting.The method of casting pump body of Tonghai pump is vacuum investment casting. This research is about reasonable casting process parameters of vacuum counter-pressure casting and vacuum investment casting.Finally qualified castings of cover and pump body of Tonghai pump can be obtained.

Abstract: Aero-engine alloys (also as known as superalloys)are known as difficult-to-machine materials, especially at higher cutting speeds, due to their several inherent properties such as low thermal conductivity and their high reactivity with cutting tool materials. In this paper a finite element analysis (FEA) of machining for Incoloy907 is presented. In particular, the thermodynamical constitutitve equation(T-C-E) in FEA is applied for both workpiece material and tool material. Cutting temperature and cutting force are predicted. The comparison between the predicted and experimental cutting temperature and cutting force are presented and discussed. The results indicated that a good prediction accuracy of both principal cutting temperature and cutting force can be achieved by the method of FEA with thermodynamical constitutitve equation.