Vibration Characteristics of Rolling Mill System under ...
2. Vibration Model of Rolling Mill System 2.1. Vibration Model of Rolling Mill System under Nonlinear Constraints. Based on the production line of Hebei Iron and Steel Group Chengde branch, the data of all the simulation experiments are derived from the structural parameters of the 1780 rolling mill and the parameters of the rolling process.
Rolling of Metals
through the grains of the metal, the rolling of threads causes improved strength, because of cold working and favorable grain flow. Figure 13.15 Thread-rolling processes: (a) and (c) reciprocating flat dies; (b) two-roller dies. Threaded fasteners, such as bolts, are made economically by these processes, at high rates of production.
Research Article Rolling Force Prediction in Heavy Plate ...
2. Mathematical Model of Plate Rolling.. Rolling Force Model. e rolling force model is in the core position in the plate model system, as it is an important parameter to develop technological system, adjust the mill, improve the product quality, expand the product range, fully and reasonably tap equipment potential, and check equip-ment strength.
Hybrid intelligent modelling and simulation for cold ...
2 Description of the rolling process dynamics As shown in Fig. 1, the simulation of a typical n-stand tandem rolling process is to describe the dynamics of rolling mills, rolled strips, hydraulic systems and electric systems. The output variables of the n-stand tandem rolling process include interstand tension
Rolling of Metals: Process and Principles (With Diagram)
The rolling process is shown in Fig. 2.1: Rolling is done both hot and cold. It is accomplishes in rolling mills. A rolling mill is a complex machine having two or more working rollers, supporting rollers, roll stands, drive motor, reducing gear, flywheel, coupling gear etc. Rollers may be plain or grooved depends upon the shape of rolled product.
Lecture 2.2: Manufacturing and Forming - UL FGG
2.2 Hot Rolling 2.2.1 Description of the Rolling Operation. Hot rolling involves reheating of ingots, slabs, blooms or billets to the region of 1200 - 1300°C and passing the material between two rolls (Figure 8). The piece of steel may be passed repeatedly back and forth through the same rolls with the roll gap being reduced progressively.
Deformation Processing - Rolling
Flat Rolling Analysis Results – without front and back tension p p µp µp σ σ x x + dσ x Stresses on Slab in Entry Zone Stresses on Slab in Exit Zone p p µp µp σ σ x x + dσ x Using slab analysis we can derive roll pressure distributions for the entry and exit zones as: …
Analysis of Vertical-Horizontal Coupling Vibration ...
Nonlinear dynamic rolling forces in the vertical and horizontal directions are, respectively, established, considering the impact of vertical and horizontal directions vibration of rolls. Then a vertical-horizontal coupling nonlinear vibration dynamic model of rolling mill rolls is proposed, based on the interactions between this dynamic rolling force and mill structure.
Development of a Mathematical Model for Plate Mill
An approach which showed good agreement with real industrial rolling load data can be described by the expression. P = b l d K Q p. where P is the rolling load, b is the width of the rolling stock, K is the hot flow strength of the steel, l d is the length of contact between the rolls and rolling stock, and Q p is a geometrical factor.
Chapter 4 Surface finish and friction in cold metal rolling
METAL FORMING SCIENCE AND PRACTICE The flattening rate W is a function of the real area of contact area ratio A and the ratio p Y of the mean contact pressure to the plane strain yield stress of the strip, i.e. = A Y p W W, (4.4) The theoretical flattening rate W is in the range 1–8, increasing with increasing mean pressure and falling with increasing area of contact ratio.
Question Banks - Manufacturing Process III
In rolling a slab from 35 to 3omm, calculate the coefficient of friction and the length of contact. Take the value of roll radius as 250mm. Q10) Calculate the rolling load if steel sheet is hot rolled 30% from a 40mm thick slab using 900mm diameter roll. The slab is 760mm wide. Assume µ=0.30.
(PDF) Load Analysis in Hot Steel Rolling (a brief overview ...
Load Analysis in Hot Steel Rolling (a brief overview) 1. Introduction Mathematical models of the flat rolling process are numerous and are easily available in the literature. They provide estimates for variables such as roll separating force, and a variety of auxiliary factors such as temperatures of the rolled material and rolls, rolled solid ...
US3714805A - Control system and method for concurrent ...
The thickness of the plate delivered from the rolling mill can be expressed as a function of the cooperating forces produced during operation of the mill by the following expression 2 o GlP) (Q/ g) G/B) (Equation 1) where h, no-load roll gap between the work rolls P= rolling load M the modulus of the rolling mill parts, which modulus is a ...
Bifurcation Characteristic Research on the Load Vertical ...
In the metallurgical industry, the rolling mill represents a core piece of equipment. However, it has been found that there are always some parameter changes or disturbance factors during the rolling process, which may induce vibration in the rolling mill [1,2].This may even cause the load roll system to produce vertical vibration with large amplitude, leading to production accidents such as ...
Frontiers | Modeling of Rolling Force for Thick Plate of ...
During the rolling process of thick plate, the nonlinear specific plastic power that derived from the non-linear Mises yield criterion is difficult to be integrated, which has restricted the establishment of a rolling force model. To solve this problem, a new yield criterion is firstly established, and then used to derive a linear specific plastic power.
Rolling force calculation - in summary, the calculation of ...
FOUR HIGH ROLLING MILL . To analyze rolling without slipping, we first derive the linear variables of velocity and acceleration of the center of mass of the wheel in terms of the angular variables that describe the wheel's motion. The situation is shown in (Figure). Figure 11.3 (a) A wheel is pulled across a horizontal surface by a force.
Rolling Mill Load Calculation
Title: Rolling Mill Load Calculation Author: OpenSource Subject: Rolling Mill Load Calculation Keywords: rolling mill load calculation, maintenance for productivity rolling models abb group, rolling mill performance maths in industry org, bearing load calculation ntnglobal com, vol 4 issue 2 february 2017 analysis of static and, roll pass design ispatguru com, load analysis of rolls in a ...
Friction Coefficient's Numerical Determination for Hot ...
In this paper, a non-linear quadratic expression of the coefficient of friction at both entry and exit sides have been derived from the equations of rolling load in Hot Rolling Bland and Ford's program (HRBF).
Experimental and Theoretical Study on Minimum Achievable ...
However, in this experiment, the rolling load of mill is limited to a maximum value of 200 kN. The rolling force provided by the mill is not high enough to roll the foils to the theoretical minimum achievable thickness. In order to achieve a thickness close to the theoretical minimum, a mill of higher rolling load should be used.
Rolling mill including means for compensating for roll ...
3. In a rolling mill according to claim 2 wherein said proportional factor is modified by another factor K in which said K factor is greater than 0.5, but less than 2. 4. In a 4-high rolling mill having a housing including a pair of work rolls between which is formed a roll gap, 5. In a 4-high rolling mill having a housing including a pair of ...
Nonlinear vibration characteristics and time-delayed ...
An expression for the dynamic rolling force of a rolling mill is derived in terms of the vibration and process parameters by analyzing the dynamic rolling process. A nonlinear vibration model of the rolling mill rolls is established. The amplitude-frequency and bifurcation equations are obtained using a multi-scale approximation method, to solve the dynamic equation with time-delayed ...
Mechanics of Cold Rolling of Thin Strip | IntechOpen
2. Roll deformation of 4-high rolling mill. As symmetry of the mill about the mid-span of the rolls, the calculation process involves one half of a roll system. Given in Fig. 1, one half of the roll barrel and the strip are divided into m and n slab elements respectively. The rolling pressure, the pressure between the work roll and backup roll ...
Dynamic modelling and simulation of a hot strip finishing mill
A 7-stand finishing mill is shown in Fig. 2, together with the runout table and coiler.Typical values for strip thickness, temperature and speed are also given. A 4-high mill stand consists of two work rolls and two backup rolls supporting them, the former having a smaller diameter as seen in Fig. 2.The backup roll supports the work roll to mitigate the deflection caused by the deformation force.
Bifurcation characteristics of torsional-horizontal ...
2. The coupling vibration model with friction of rolling mill. In the study of rolling mill driven by the motor, in order to simplify the model and conform to actual physical meaning, rolling mill drive system is usually abstracted into two parts, which are the motor terminal and the roller terminal according to lumped mass method.
Development and Study of a Microprocessor-Equipped System ...
A new microprocessor-based system for monitoring rolling forces has been designed and built, the system making it possible to measure and record changes in the load on the rolls along sheet that is in the process of being rolled. Introduction of the monitoring system was the second stage in the modernization of the two high 150×235 mill in the laboratory of the Metal-Shaping Machines and ...
1. Hot rolling and rolling defects: 1.1 Front and back ...
Gage control in multiple rolling mills is achieved through measurement of strip thickness using x-ray gage and adjusting the strip tension using feedback control system. 1.8 Rolling defects: Mill spring is a defect in which the rolled sheet is thicker than the required thickness because, the rolls get deflected by high rolling forces.
Instability Condition Derivation for Hydraulic AGC System ...
In strip rolling, hydraulic automatic gauge control (HAGC) system is the key element to guarantee the precision of strip gauge. The stability of the kernel pressure closed loop (PCL) in the HAGC system plays an essential role in guaranteeing the rolling process with high performance. Nevertheless, there is some difficulty in exploring the instability mechanism of the HAGC system due to the ...
Nonlinear vibration characteristics and time-delayed ...
dynamic vibration model of the rolling mill rolls, as shown in Fig. 2. Fig. 1. Structural diagram of a four-high hot rolling mill In Fig. 2, the solid and dotted lines indicate the steady-state and vibration positions of the rolling system, respectively. I 5 and I 6 are the equivalent masses of the upper and lower rolls,
US7854155B2 - Method and rolling mill for improving the ...
A method for improving the running-out of a metal rolled strip ( 1 ), the rolled trailing strip end ( 1 a ) of which exits out of a respectively last roll stand ( 2 ) of a multistand rolling mill ( 3 ) at a rolling speed, wherein during rolling between two consecutive roll stands (F 1, F 2, F 3 . . . Fn) the strip tension (a) is adjusted to stabilize the strip position, provides that shortly ...
4-High rolling mill - , Ltd.
9. A 4-high rolling mill according to claim 8, wherein "n" is between 2.0 to 2.5. 10. A 4-high rolling mill according to claim 8, wherein a maximum shift amount of said roll shift device is about 1/2 of the difference between a maximum and a minimum width of the material to be rolled. 11.