Abstract: The velocity field is devided into the basic and additional fields. The basic velocity field should satisfy given conditions on boundary, but the additional velocity field should only satisfy the uniform boundary conditions. Corresponding to those two parts of velocity field there are basic flow function and additional flow function. The basic flow function can be written definitly, while the additional flow function, according to the Weierstrass theorem, has been written as a family of vectors in complete space, i.e. a polynomial. With the aid of minimization of the total power the coefficients of the polynomial hare been defined. By using this method, the following results are obtained: velocity field, field of strain-rate, stress field, the back and front boundaries of plastic zone, the position of neuture point on the contact arc, and the rolling pressure acting on the contact surface of the strip.
Abstract: This paper emphatically discusses the influence of the roll crown on the deformation of the roll system and the rolling pressure, and the corrected equations are verified by test, shows their arailablity in practical engineering.
Abstract: The paper investigates the chatter phenomenon about 120~250Hz often occurred during the rolling of cold strips establishes a more reasonable dynamic model of the chatter, and simulates the chatter process. The chatter is a self-excited vibration resulting from the inherent instability of rolling process increasing with rising rolling speed. The limit speed up to which the chatter occurs varies with difference of technology parameters of rolling and specification of cold mill. The mistakes about chatter mechanism existing in the research articles of some foreign investigators are pointed. The measurements which may prevent from chattering with reasonable design and operation of cold mill are given by the analysis and simulation.
Abstract: Compress experiments on 5139 samples of nine grades of carbon steel which were collected from 1700 hot strip mill in WISC were made by a cam plastometer with constant strain rate, the flow stresses of carbon steels measured. Seven appropriate types of flow stress mathematical models were chosen to make regression analyses of these experimental data. A new - mathematical model was obtained in wfich the influences of main chemical elements in carbon steel and deformation conditions were fully considered. The structure and effect of new mathematical model are better than that of being used and it has been successfully used for on-line production control of 1700 hot strip mill in WISC.
Abstract: The photoelastic-photoplastic material selective principle and loading equipment of cutting are introduced. The isochromatic photographs of elastic de-formation and crack extensive residue, crack extension at cutting, the stress distribution on the surface of cutting tools which contact with the metal and the relation between cutting stress and b/h are given.
Abstract: Two kinds of torsional vibration responses are discussed whicl produced in drive system of blooming mill owing to the roll slippage during working course. By means of fracture mechanics the fracture torque is calculated according to the cracks appeared in damaged section of the wobbler. The calculated fracture torque is in accordance with two kinds of torsional vibration responses.
Abstract: The power calculation methods of three-roll planetary mill by using cone rolls are discussed. A series of formulas, including the deformation zone, contact area, rolling force and rolling torque, are presented for practical use.
Abstract: A new method is approached here by simulating the action of rolling elements with nonlinear elastic supports. The system deformation is considered. The results show that the rolling element load distribution has close relationship with the chock stiffness and bearing clearance. When the stiffness is relatively small the load is double-peakly distributed but not single-peakly as described in conventional analytical method.
Abstract: To insure the rotation of rolled parts is the fundamental condition for building normal rolling process in cross wedge rolling. Under the same technique, there will be a most difficult area to rotating the part, it is neither in the begining nor in the stretching shaping part of the wedge, it is around the highest point of the wedge from its begining where the rolled part rotates about half a circle (θ=π). It has been demonstrated by not only practice also the formulas of rotatory condition.
Abstract: Roll pass design of straight welded tubing with CAD method have been developed in order to raise the efficiency and the quality of products. By using this system, calculation of parameter, drawing roll-flowers and drawing roll contouring were accomplished in ten minutes. Design period for a set of spare graphs have been reduced from one month to several hours. The functions and characteristics of the computer-aided design system for roll pass (ZHG-CAD) are described.
Abstract: Nowadays The swivel of many hydraulic clay gun is performed by a piston cylinder and a rod mechanism. The formulas for the maximum force acting on the piston and for the relation between swivelling cylinder travel and the angle of the arm are given by the analysis of the swivelling mechanism, which provides basis for designing, calculation and optimizing the parameters of the rod mechanism.
Abstract: Measurement and analysis of productivity and screening efficiency on the TZ120-240 single layer screen and the 2TZ120-240 double layer screen are carried out by using orthogonal design method. The influence of altitude, direction angle, angle of the screen surface and burden thickness on productivity and screening efficiency is revealed. The optimum plan of all of the parameters is also found.
Abstract: Torque value and its variation rules for withdrawal rolls in different positions under four working conditions were derived on the basis of measuring and analyzing for multi-roll withdrawal and straightening systems of heavy continuous slabs casting machines. It is of great significance to the continuous casting production and the design of multi-roll withdrawal and straightening systems.
Abstract: Using axisymmetric theory of plane problem in elasticity and considering, the influence of controlled collapse, a new calculating method is developed, in which the radial stress and the coil hoop stress are studied together. Some curves have been made and by which the radial pressure can be calculated easily. The calculated results are similar to that measured in experiment.
Abstract: For rotary flying shears in a starting working state, it have an obvious effect of the rotary radius of its knife-edge and the ratio of its drive gear on the starting time, the strength of the driving parts and the operating load of main motor. The rotary radius of the knife-edge and the ratio of the drive gear are expressed.
Monthly, started in 1955 Supervising institution：Ministry of Education Sponsoring Institution：University of Science and Technology Beijing Editorial office：Editorial Department of Chinese Journal of Engineering Publisher：Science Press Chairperson：Ren-shu Yang Editor-in-Chief：Ai-xiang Wu ISSN 2095-9389CN 2095-9389
