Kolupaeva Irina 

Physical and Metallurgical Faculty

Speciality: Metal Deformation Process

Scientific adviser:  professor Yakovchenko Alexander 

Improvement of technology of production of railway wheels with curvilinear disk and design method calibration

    The purpose of work is development of methods of computer-aided design calibrations and development of new technology of stamping and rolling of wheels, which allows to reduce metal consumption and marriage at the box office and the non-accomplishment of the comb through the use of accurate mass and billets prior formation of the ridge before rolling.

    Improvement of the technology of production of wheels with accurate and the reduced mass of up to (470-475) kg initial blanks requires the development and analysis of new technological schemes and calibrations and choose from them the most rational. The new technology is to provide higher the accuracy of wheels and a reduction in metal consumption.

    In this work we considered the technological scheme of forming of wheel billets with a crest. This scheme foresees the use of upper figured plates on the blank the media power 50 MN and provides preliminary forming part of the rim and hub. This scheme, in contrast from the existing technologies at JSC "VYKSA steel works" and JSC "NTZ", provides upset starting stock (after her the heating and the operation of asynchronous scale) on the press by force 20 MN in the upper technological ring. Can be used suspended technological ring or upper floating technological ring. But in one and in the other the need to ensure eject blank. Simultaneously with the draft is formation of part of the lateral surface of the workpiece. Then logging turned and fed at a press force of 50 MN.

    Centering blanks in the lower technological ring presses with the effort is 50 MN for отформованной on press by force 20 MN conical side surface of the workpiece. With lower technological ring press stress 50 MN in this case, once installed on the axis stamping. Deformation of metal on the media power 50 MN is executed after lowering the upper shaped stamp or upper plate figured.

    Allow significant reduction of the asymmetry of pieces on presses with force 20 MN, 50 MN and 100 MN. The upper moulding stamp performs самоцентрування workpiece. Самоцентрування is possible because the logging is not clamped stamps in the first moment of contact (as is the case with the existing technology. The first contact with the workpiece forming the ring, which executes it самоцентрування. So it is possible to consider the issue of exclusion centering preparations for the press a force of 100 MN трьохважеля центрователя. These measures combine to provide stable dimensions wheel billets, to have lunch, drive and the hub, which will significantly increase the accuracy wheel sizes.

    There is a need to improve methods of computer-aided design calibrations on metal and calibration of the instrument of deformation for the production of штамповано-rolled wheels. Calibration on the metal there is a set of contours of cross-sections of wheel billets and rough wheels that get upset, forging and rolling on all machines пресопрокатной line wheel-rolling mill. On the basis of calibration on metal are developed calibration tool deformation: calibration of the rolls (inclined, the main lever) and templates (molding). Calibration developed against a course of stamping and rolling.

    First, on the basis of contour crossing of the wheel, which get on вигібном the press, is developed calibration on metal for the KPS. The crossing of the wheel, which get to the KPS, necessary for the design of circuit section wheeled billet, received on формировочном press. In the future digital information on these contours in the automatic mode should be transferred to the corresponding window, where is the design of calibers. After reception of the digital information already the size should be transferred to the corresponding window for the design of the rolls. And at each stage should calibrator doesn be able to manage this process, including the control of digital and graphic information, to determine the modes of operation, adjust the any size in available for this table.(figure 2).

    In the right part of the window is the construction of the contour section draft wheel after the KPS, combined with the contour of a draft wheel after вигібного press. In the bottom part of the window provides a table, which is calculated as the weight of all designed wheel after the KPS, and the mass of its separate parts (rim drive and the hub). Moreover, in parallel are calculated the same masses the draft wheel after press. This comparison allows to specify the value of reductions of the wheel on the press and, accordingly, the sizes of all the main elements of the wheel.

    Design of calibration for transition "KPS - forming press" is responsible stage, because the shape and dimensions of відштампований wheeled billet should provide rolling the KPS wheels without defects of rolling of origin. Improving the models was associated with the need to ensure possibility of designing of the calibrations from the previous formation of a crest on press the power 100 MN.(figure 3).

    In terms прессопрокатних lines колесопрокатный OF shops OF open society "Interpipe NTZ" and JSC "VMZ" sediment blanks in the lower technological ring and their dispersal perform in the media power 50 MN. Pre-acceleration the besieged blanks perform the punch, the diameter of which, as a rule, is equal to 500 mm.

    Calibration on metal for procuring the press is developed on the basis of calibration metal forming presses. She determining the mode of deformation of metal forging wheel parts, the first of turn, should provide the virtually simultaneous filling metal-forming dies in the rim and hub.(figure 4).

    Once you have selected the type of calculation and in the table of the initial information preset values: distillation of the blank; radius;bias of technological rings and other values, you need to specify parameters balance, received on the press (in the conditions of JSC "Interpipe NTZ" and JSC "VMZ" this is a press force of 100 MN)(figure 5).

    Here after the control of the contour section will design-bathroom-control its entry in the molding dies. At the same time is calculated size of the gap between the workpiece and forming the ring for the first time stamping. Size of the gap exerts a certain influence on the forming of metal. Therefore, to obtain required gap calibration can be changed(figure 6)

    Followed by a calculation of the mass workpiece. Blank weight is defined as the sum of the masses preparation of press force 20 MN and metal waste.

Conclusions:

    1. For visualization of metal forming in molding dies press the power 100 MN when forming the wheel blanks with the crest of the blanks part of the prepared press 50 MN rim and hub at a ratio of hT / hD in the range of 1-1 .2.

    2. For the design of calibration on metal for transition "press the power 100 MN - KPS" and determine the radial and axial compression metal.

    3. When rolling the wheel blanks with comb it is possible to eliminate defects such as failure to crest and the west on the ridge with the inside of the wheel, which is associated with overflow metal ridge part of the caliber.