Papers by Keyword: Forging

Abstract: This paper describes the experimental study and modeling of the process of cross wedge rolling workpiece for the stamping of the crankshaft using a tool printed on a 3D printer. The study shows the design and printing features of the tool for cross wedge rolling. A comparison of the experiment and simulation in Qform program.

Abstract: This paper used finite element analysis of metal forming to study the forging process and die design of aluminum alloy brake parts. According to the process parameters and die design, the brake parts were forged by experiment. First, the die design is based on the product size and considering parting line, draft angle, forging tolerance, shrinkage and scrap. Secondly, the finite element analysis of metal forming is used to simulate the forging process of aluminum alloy brake parts. Finally, the aluminum alloy brake levers with dimensional accuracy and surface hardness were forged.

Abstract: In the forging industry, rolling is used to produce ring forgings, which are widely used in power and nuclear engineering. According to the technical conditions and established practice, large ring forgings are made using the operations of precipitation, piercing and rolling out with a striker on the mandrel.

Abstract: It is shown that deformed steel has an advantage over cast steel in terms of mechanical properties. It was revealed that the decrease in the durability of gear parts is associated with the presence of metallurgical defects in the steel. The square segregation is always inherited by the finished part and its appearance on the surface leads to the destruction of the product. The dendritic structure of steel is the reason for the low endurance strength of the tooth of the part. For heavily loaded gear parts of the «shaft-gear» type, it is recommended to use rolled products with a high degree of crimping (extension). To eliminate the dendritic structure in steel, hot deformation of the metal can be carried out at the stage of forging production.

Abstract: Ti-6Al-4V is used as a high-performance material in many industries (mainly automotive and aerospace, but also the medical industry) and traditionally produced by hot forging, with subsequent extensive post-processing and machining, leading to a material yield far from 100 % [1]. New production chains, such as additive manufacturing, enable the near net shape production of high-performance parts, however, still with long production cycles and high manufacturing costs, especially for larger parts [2]. Therefore, an efficient and feasible production is often limited to low quantities and/or small pieces. In the present study, we propose a hybrid manufacturing route, combining additive laser metal deposition (powder LMD) on hot forged base components, enhancing material efficiency, but still enabling the production of industrial quantities. Primary investigations on the microstructure and mechanical properties of the material show results similar to conventional hot forged material, but reduce the number of processing steps and increase the material yield.In more detail, the relationship between the primary beta grain size and the secondary alpha phase characteristics was investigated and moreover, related to the cooling history of the material. Furthermore, the influence of the microstructure and phase characteristics on the mechanical properties of the material was analyzed. For the determination of the primary beta grain size, the programming language MATLAB as well as its integrated open-source toolbox MTEX were used, where a GUI has been developed for the reconstruction of the primary beta grain orientations and sizes from recorded EBSD data of the secondary alpha (Ti) phase, using the Burger’s orientation relationship (BOR, [3-7]).

Abstract: The structure and misorientations of grain boundaries of ultrafine-grained nickel subjected to rolling and forging at liquid nitrogen temperature are studied. It is shown that as a result of rolling in UFG nickel obtained by the ECAP the forming of a band fragmented structure with the formation of special twin boundaries Σ3 is observed. An increase in the strain rate (forging) leads to the appearance of localized deformation bands in which the formation of new small grains is observed through dynamic recrystallization. The development of recrystallization results in increase up to 7% in UFG nickel the fraction of special twin boundaries Σ3 which are similar in nature to annealing twins.

Abstract: An in-house 2D finite volume model, specific for components of simple shape, was developed and applied to predict the thermal and microstructural evolution during heat treatment of steel forgings. The results of the thermal metallurgical modelling, including hardness profiles through the thickness, were compared with the experimental ones. Moreover, the 3D FEM software Deform-HT, able to calculate the thermal and microstructural evolution and the stress field during quenching, was specialized for the cases of interest. Examples of optimal heat treatment to develop the target microstructure and strength and reduce the risk of quenching cracks are discussed.

Abstract: The aim of this work was to analyse the microstructural nature of plasticity in ZnAl4Cu1 alloy and its dependence on the processing technology. The alloy condition was analysed after gravity casting, after forging and after ECAP processing. Two alloys with slightly different compositions were studied. For alloy A, the returnable material from a prominent Zn alloy producer was used. For B alloy input raw materials of relatively high purity were used. Tensile testing showed that in the as-cast alloy tensile strength had relatively low levels up to 211 MPa, and particularly low values of ductility only up to 2.5 % were found in B alloy, which was more polluted. By means of ECAP processing of the as-cast alloy, the tensile strength was improved by 50 % (Rm = 312 MPa). In the case of the purer A alloy the majority of samples improved to level A = 27.9 %. Forging of the as-cast alloy preserved strength on a level similar to the ECAP result, but ductility was improved to the level of 34.4 %, although alloy B had lower purity. Further significant ductility improvement was obtained through ECAP processing to A = 147 % of the as-forged alloy. The microstructure of ZnAl4Cu1 consists primarily of segregated η phase (rich in Zn) and fine eutectoid composed of η and alpha phases segregated mostly in dispersive state, but in places also in lamellar form. Close correlation between microstructure and processing method resulted from our fractographic study. In the case of ECAP processing of the forged state the finest microstructure was achieved, which was accompanied by higher plasticity and also by fine dimples of transcrystalline ductile fracture (DTDF).

Abstract: The main purpose of this contribution is to create a methodical procedure for numerical simulation of the forging process using FEM of a real part, which is produced in three forming operations. Then this process will be realised step by step for creation simulation model in the simulation software DEFORM 3D, where the output data will be calculated on an example forging process on real component. The obtained results are then compared with reality to determine the degree of match between simulation results and real component. The 3D models of dies for each operation as well as some input parameters were obtained from HKS Forge. This company is leading manufacturer of die forging for the engineering industry in Europe. Proposed methodical procedure can serve as a basis for creating additional simulation models that could simulate the wear of these dies during long time of use.

Abstract: When utilizing current combined systems of manufacturing large-sized shaft forgings, there is a tendency towards using an integrated approach, which consists in optimizing the shape of forged ingots and methods of their forging, intensifying shear strains in the axial zone of the ingots during their plastic deformation, and eliminating asymmetry of external forces at various points along the cross section of the ingot being deformed. This paper presents the results of the comparative analysis of quality of shaft forgings when forging ingots with a three-beam symmetric and asymmetric cross-section, as well as with the traditional octahedral cross-section, are used for the manufacture of shaft forgings. It has been shown that the use of forging ingots with a three-beam symmetrical and asymmetrical cross section provided an increase of KCU by an average of 4.3% and 13.1%, and of density by 17.5% and 21.0%, respectively, in the absence and presence of inert gas (argon) blowdown of the melt in the casting ladle before casting it into ingot molds. Their use also contributes to an increase in the number of forgings, suitable for ultrasonic testing, according to the C/c class with a permissible equivalent discontinuity diameter of ≤ 3 mm.