FEM analysis of the manufacturing of hollow forgings from a tube billet

The study presents an analysis of the manufacturing process of a hollow forging. The process was proposed to consist of three stages. In the first stage (extrusion) wall thickness was reduced and the flange was formed. In the two subsequent stages the flange was formed. The material flow was examined using FEM. The issue of defect occurrence in the area of a hole caused by the material moving away from the mandrel was especially researched. Moreover, the strain state was analysed in the following forging operations. The distribution of the fracture criterion was presented. Moreover, a prediction of the forces necessary for the process to be performed in real conditions was carried out. The conclusion is that the proposed scheme of forming hollow forgings may be implemented in industrial conditions.

Study of tube billet reduction to obtain constant wall thickness

Analysis of material thickening process during reduction operation is presented. In order to obtain constant thickness after reduction by conical die thickness distribution of the workpiece is proposed. Workpiece with required thickness distribution is manufactured by thinning drawing. Experimental verification of proposed thickness distribution in order to obtain constant thickness after reduction operation is carried out.

MODELING THE WORK OF THE HEAD OF A HYDROMECHANICAL EXPANDER FOR WELDED PIPES OF A LARGE DIAMETER

Finite element simulate of the operation of the expander head during the calibration of welded bulky pipes was carried out. The forces required to move the parts of the expander power drive are determined. It is shown that a change the length of the cylindrical surface of the wedge segments of the expander and the axial movement step size with constant radial extension of the segment changes the distribution of plastic deformation in the tube billet s.

Theoretical substantiation of reverse isothermal extrusion scheme of pipe billet with active friction and drawing of its edge part

Method consisting in the implementation of the reverse extrusion process of tube billet in isothermal сondition of stamping with active friction is considered. Feature of the method is the simultaneous use of friction forces and pushing of the formed thickened edge part of the workpiece and its further straightening. The force conditions and stress state in the product are estimated. Comparison of this method with the classical extrusion scheme is given.

Development of rational deformation mode of tube billet in continuous roll forming

Universal formula is proposed for calculating the optimal strip width and tube-billet perimeter at each stage of bending in the production of electrowelded low- and medium-diameter straight-seam tube and pipe of round and complex cross section. This formula determines the conditions of tube deformation in machines of different type and allows the increase in tube-billet perimeter in group of stands with open gauge profi le to be taken into account for different forming behavior. For the tube and pipe range produced, the reduction at the tube-billet perimeter in group of stands with closed gauge profi le should be no more than 0.6 %. That decreases the steel consumption by decreasing the width of the initial billet, without loss of pipe quality, and increases the product yield by eliminating edge buckling in the course of forming.

Effect of protective coatings on serviceability of aluminium alloys in environment of oil production

The effect of protective coatings on the wear resistance and corrosion resistance of the 2024 aluminium alloy used for the oil drill pipes producing is studied. The nature of the drill pipes damage made of aluminium alloys during operation is analyzed. The microstructure of the coatings, the electrochemical potential and corrosion rate of the 2024 aluminium alloy with and without coatings of various compositions are studied, and comparative analysis of the adhesion and wear resistance of coatings is performed. It is shown that tube billet made of 2024 alloy with сoating based on tungsten carbide has the highest range of service properties and can be used to effectively protect the surface of aluminium drill pipes during operation.

New Technologies for Producing Bicycle Hub Forging

The paper presents the results of research on two new forging processes for producing bicycle hub forgings in a three-slide forging press. The first process is related to producing a forging with an axial cavity by flashless forging. The other one concerns the production of a forging from a tube billet. The potential benefits offered by these two new forging processes compared to the conventional hammer forging method for producing hubs are discussed. The designed processes are verified theoretically via numerical simulations. The first of the proposed processes is also subjected to experimental verification. The results demonstrate that the new technologies allow obtaining good quality products. A comparison is made between material and energy consumption in the two analyzed processes and in conventional hammer forging. It is found that the application of the forging process in a three-slide forging press leads to a considerable decrease in manufacturing costs.

NUMERICAL SIMULATION OF THE BULK FORMING PROCESS TO MANUFACTURE COUPLING DETAILS FROM TUBE BILLET

Currently, most coupling details in the actuators are made by traditional methods such as bulk forming from block billet and then metal cutting. Such manufacturing methods often lead to material wastes due to cutting a large amount of excess processing. To save material and improve production efficiency, tube billet would be selected for bulk forming. However, when tube billet is used for bulk forming, it should be carefully calculated to avoid instability and folding defects in workpiece. This article presents the research on the forming process of the coupling details using numerical simulation and based on the obtained results, the suitable geometric size of tube billet for the forming operation in closed die can be determined.