scholarly journals System dynamics of a pipe pilger CRM working stand

2019 ◽  
Vol 75 (6) ◽  
pp. 725-734
Author(s):  
S. P. Rakhmanov ◽  
V. V. Povorotniy
Keyword(s):  
Optimal Design ◽  
Cold Rolling ◽  
High Speed ◽  
Rational Design ◽  
System Analysis ◽  
High Efficiency ◽  
Rolling Process ◽  
Calculation Algorithm ◽  
Cold Rolling Mills ◽  
Analysis Of Dynamics

Efficiency of the pilger cold rolling of pipes process realization can be increased both by perfection of the rolling process and by a selection of rational parameters of the base technological equipment and the mills functioning regimes. Particular attention should be paid to the increase of reliability of functioning, increase of high-speed and productivity of pipe cold rolling mills (CRMs). Results of the system analysis of dynamics of pipe CRM working stand of various designs presented. A calculation algorithm elaborated and differential equations of the pipe CRM working stand obtained. Pictures of dynamic motions for selected pipe CRM working stand obtained. The analysis of theoretical studies showed, that for stabilization of the stand base elements it is necessary to increase the rigidity of the working stand correspondent elements. It was shown, that the stand rigidity increase reached by arrangement longitudinal bridge of variable thickness, connecting the internal and external structure’ casing. An optimal design roller actuator elaborated. Implementation of the actuator will enable to accomplish the technological process more effectively, since the unit’ elements can adopt all possible inaccuracy of the working stand manufacturing and assembling, as well as housing post deformation. It was ascertained, that the roller actuator of optimal design, above all, plays a role of an emergency gear of the pipe CRM working stand. The studies revealed that increase of productivity and quality of the manufactured products reached mainly by application of the working stand of rational design at the pipe CRM. The industrial running the modified variant of working stand design during eight years to roll hard-deformed steels and alloys confirm its high efficiency at production of precision high quality pipes.

Research on the Stress Uniformity of the High Speed Bearing with Heavy Load in Cold Rolling

2014 ◽  
Vol 599-601 ◽  
pp. 422-425
Author(s):  
Zhe Hong ◽  
Bao Shou Sun ◽  
Bin Hu
Keyword(s):  
Cold Rolling ◽  
High Speed ◽  
Roller Bearing ◽  
Rolling Process ◽  
Fe Model ◽  
Feed Speed ◽  
Heavy Load ◽  
Tapered Roller Bearing ◽  
Bearing Rings ◽  
Stress Uniformity

An FE model is established on the basis of ABAQUS software for simulating the closed cold rolling process of the high speed TRB (tapered roller bearing) with heavy load. The influences of the feed speed, main roll rotational ratio, and initial angle between two guide rolls on the stress uniformity of the formed bearing rings are studied by evaluating the standard deviation of the Von Mises on all elements in the FE model. The research shows that the stress uniformity of the formed bearing rings decreases with the increment of the feed speed; the stress uniformity increases with the increment of the main roll rotational ratio; and the stress uniformity increases with the increment of the angle between two guide rolls.

Process and Properties on the Precision Forming of Spline Cold Rolling

2010 ◽  
Vol 154-155 ◽  
pp. 191-196 ◽  
Author(s):  
Zhi Qi Liu ◽  
Jian Li Song ◽  
Yong Tang Li ◽  
Xu Dong Li ◽  
Ming Fu Wang
Keyword(s):  
Plastic Deformation ◽  
Cold Rolling ◽  
High Efficiency ◽  
Flow Line ◽  
Metal Flow ◽  
Impact Resistance ◽  
Rolling Process ◽  
Plastic Deformation Zone ◽  
Forming Process ◽  
Involute Spline

Cold rolling precision forming process of spline is one of the high-efficiency, precision and non-chip forming advanced manufacturing technologies. It has the characteristics such as high forming efficiency, energy-saving, low material consumption and better forming properties of components. The principle and the force of involute spline cold rolling precision forming process were analyzed. Forming experiments of involute spline cold rolling were carried out, and the microhardness map of the tooth outline was gained. The rule of the metal flow in the deforming area and the forming mechanics of the microstructure were analyzed. The influence of plastic deformation on the forming properties was also conducted. Experimental results showed that dramatic plastic deformation has taken place on the upper surface of the workpiece during the cold rolling process of spline, while the influence on the inner materials were very small. The grains were distributed as a flow line pattern along the tooth profile, and the grains in the plastic deformation zone presented a fine and long fibrous state. The hardness on the section of the tooth outline is regularly distributed. Compared with the spline components obtained from conventional cutting method, the hardness of the spline was greatly increased, therefore, comprehensive mechanical property such as wear resistance and impact resistance were largely improved. Precision measuring and hardness testing of the tooth outline section showed that the components obtained by the experiments were free of defects, and the application requirement can be satisfied.

High-speed rolling by hybrid-lubrication system in tandem cold rolling mills

2015 ◽  
Vol 216 ◽  
pp. 357-368 ◽  
Author(s):  
Yukio Kimura ◽  
Noriki Fujita ◽  
Yukihiro Matsubara ◽  
Koji Kobayashi ◽  
Yosuke Amanuma ◽  
...  
Keyword(s):  
Cold Rolling ◽  
High Speed ◽  
Lubrication System ◽  
Rolling Mills ◽  
Tandem Cold Rolling ◽  
Cold Rolling Mills

Modeling and Optimization of Rolling Process: A Multi-Objective Approach

2020 ◽  
Vol 19 (02) ◽  
pp. 343-364
Author(s):  
S. Panda ◽  
S. N. Panda
Keyword(s):  
Cold Rolling ◽  
Film Thickness ◽  
Temperature Rise ◽  
High Speed ◽  
Rolling Process ◽  
Response Analysis ◽  
Strip Rolling ◽  
Multi Objective ◽  
Inlet Zone ◽  
Cold Strip Rolling

In a high-speed cold strip rolling process, it is necessary to optimize the process parameters for improved quality in the product. In this study, two separate multi-objective optimization problems for a cold rolling process are formulated. The objectives in one of the cases are minimum isothermal film thickness and film temperature rise in the inlet zone and in another case it is minimum thermal film thickness and film temperature rise in the inlet zone. Particle swarm optimization algorithm has been used for solving the optimization problem. The key input parameters for the cold rolling process are identified and prioritized through the convergence study and the coefficient of variation analysis. A response analysis is performed on the critical input variables. This study assists the process engineer to understand the lubrication in cold strip rolling at high speed and select an appropriate lubricant for a given combination of strip and rolls.

scholarly journals Analysis of the Reasons for the Tearing of Strips of High-Strength Electrical Steels in Tandem Cold Rolling

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7124
Author(s):  
Ivan Petryshynets ◽  
František Kováč ◽  
Ladislav Falat
Keyword(s):  
Cold Rolling ◽  
High Speed ◽  
High Efficiency ◽  
Steel Strip ◽  
High Strength ◽  
Bimodal Distribution ◽  
Dislocation Motion ◽  
Temper Rolling ◽  
Final Thickness ◽  
Tandem Cold Rolling

High-strength non-oriented electro-technical steels with a low thickness possess excellent isotropy of electromagnetic and mechanical properties which is highly required in the production of high-efficiency electric motors. The manufacturing process of this type of steel includes very important and technologically complex routes such as hot rolling, cold rolling, temper rolling, or final heat treatment. The final thickness is responsible for the decrease in eddy-current losses and is effectively achieved during cold rolling by the tandem rolling mill. Industrial production of thin sheets of high-strength silicon steels in high-speed tandem rolling mills is a rather demanding technological operation due to the increased material brittleness that is mainly caused by the intensive solid solution and deformation strengthening processes, making the dislocation motion more complex. The main objective of this work was to investigate the distribution of local mechanical strains through the thickness of high silicon steel hot bands, generated during the cold rolling. The experimental samples were analysed by means of electron back-scattered diffraction and scanning electron microscopy. From the performed analyses, the correlation between the material workability and the nucleation of cracks causing the observed steel strip failure during the tandem cold rolling was characterized. Specifically, the microstructural, textural, misorientation, and fractographic analyses clearly show that the investigated hot band was characterized by a bimodal distribution of ferrite grains and the formation of intergranular cracks took place only between the grains with recrystallized and deformed structures.

scholarly journals Robust Backstepping Control for Cold Rolling Main Drive System with Nonlinear Uncertainties

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Xu Yang ◽  
Kai-xiang Peng ◽  
Chao-nan Tong
Keyword(s):  
Cold Rolling ◽  
High Speed ◽  
Linear Time ◽  
External Disturbance ◽  
Rolling Process ◽  
Drive System ◽  
Disturbance Attenuation ◽  
Parameter Uncertainties ◽  
Robust Controller ◽  
Main Drive System

The nonlinear model of main drive system in cold rolling process, which considers the influence with parameter uncertainties such as clearance and variable friction coefficient, as well as external disturbance by roll eccentricity and variation of strip material quality, is built. By transformation, the lower triangular structure form of main drive system is obtained. The backstepping algorithm based on signal compensation is proposed to design a linear time-invariant (LTI) robust controller, including a nominal controller and a robust compensator. A comparison with PI controller shows that the controller has better disturbance attenuation performance and tracking behaviors. Meanwhile, according to its LTI characteristic, the robust controller can be realized easily; therefore it is also appropriated to high speed dynamic rolling process.

scholarly journals Robust Tension Control of Strip for 5-Stand Tandem Cold Mills

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Behrooz Shafiei ◽  
Mohsen Ekramian ◽  
Khoshnam Shojaei
Keyword(s):  
Cold Rolling ◽  
Rolling Process ◽  
Tension Control ◽  
External Disturbances ◽  
Rolling Mills ◽  
Tandem Cold Rolling ◽  
Cold Rolling Mills ◽  
Hankel Norm ◽  
Norm Approximation

Tandem cold rolling process is a nonlinear complex system with external and internal uncertainties and significant disturbances. The improvement in the quality of the final output depends on the control strategy of centerline thickness and interstand tension. This paper focuses on interstand tension control problem in 5-stand tandem cold rolling mills. Tension dynamics can be described by a nominal model perturbed by parametric uncertainties. In order to overcome the model uncertainties and external disturbances, suboptimalH∞andμcontrollers are proposed and the Hankel-norm approximation is used to reduce the order ofμcontroller. The performance of the proposed controllers is demonstrated by some simulations.

Effect of Lubricant Scarcity on the Film Formation in an Inlet Zone During High Speed Cold Rolling Process

2007 ◽  
Author(s):  
Prahlad Singh ◽  
R. K. Pandey ◽  
Yogendra Nath
Keyword(s):  
Cold Rolling ◽  
High Speed ◽  
Heat Dissipation ◽  
Film Formation ◽  
Rolling Process ◽  
Lubricating Oil ◽  
Lubricating Film ◽  
Viscous Heat ◽  
Inlet Zone ◽  
Reduced Temperature

Effective lubrication during the cold rolling is vital in achieving desirable tolerance and surface quality over the metallic sheets. However, in the process of cold rolling, it has been established that the lubricant’s viscosity drastically reduces (viscosity thinning) due to huge viscous heat dissipation in the lubricating film at the elevated rolling speeds. Thinning of lubricant viscosity increases the escaping tendency of the lubricant from the inlet zone. Thus, scarcity (starvation) of lubricant prevails in the inlet zone of roll and strip interface. Based on the present investigation, it is observed that the existence of starvation seems to be beneficial in terms of reduced temperature rise and less quantity of lubricating oil required provided there is a continuous film at the strip-roll interface.

Numerical Simulation Study on the Cold Rolling of Hollow Thread

2010 ◽  
Vol 160-162 ◽  
pp. 849-854 ◽  
Author(s):  
Hui Ping Qi ◽  
Yong Tang Li ◽  
Zhi Qi Liu ◽  
Shi Wen Du
Keyword(s):  
Numerical Simulation ◽  
Cold Rolling ◽  
High Efficiency ◽  
Rolling Force ◽  
Low Cost ◽  
New Technology ◽  
Failure Process ◽  
Tangential Force ◽  
Rolling Process ◽  
Thin Wall

The cold rolling technology of thread was rapidly developed due to its high efficiency, low cost and perfect property of its production. But theoretical researches on the precise forming were very few, especially for the hollow parts. In the rolling process, empirical (trial and error) methods have been a mainly part. This is unfavorable for the development of the new technology. In this paper, numerical simulation of the cold rolling process of hollow thread was studied. The DEFORM soft was used to perform the simulation work. The stress field, strain field and velocity field in the workpiece were obtained. The change curve of the rolling force and the relation curve of tangential force and torque were obtained. The failure process of hollow thread in the rolling process was also simulated. The failure reason of thin wall thread in the rolling process was analyzed according to the change of effective stress in the workpiece. The result is well agreement with theoretical ones. The further research will be done to promote the application of numerical simulation in the cold rolling of hollow thread parts.

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