Effect of Material Property Changes on the Performance of Al Rolling Mills

2010 ◽  
Vol 638-642 ◽  
pp. 247-254 ◽  
Author(s):  
Kai F. Karhausen ◽  
Wolfgang Schneider
Keyword(s):  
Rolling Process ◽  
Total Production ◽  
Process Chain ◽  
Rolling Mills ◽  
Strip Profile ◽  
Process Chains ◽  
Production History ◽  
Product Surface ◽  
Property Changes ◽  
Aluminium Strip

The industrial production of aluminium strip comprises a rather long process chain. One of the characteristics of aluminium alloys is that a number of final strip properties are influenced considerably already at very early process stages. Since it is practically impossible to run large variations of controlled process changes on an industrial mill experimentally, Through Process Modelling (TPM) has been in focus of research and has developed into a valuable tool to design process chains with a view to achieving desired properties. Metallurgical models in combination with (plasto-) mechanical/thermal models trace variables of state through the process chain down to the final operation. However, there are further important properties of the product, which may be generated as consequence of the total production history. Predominant examples are the strip profile and flatness and the product surface. These properties do not only result from the processes settings, they may also have a strong back-effect on the process performance itself. As a consequence they may also affect the metallurgical properties. This paper shows representative computations of in-dustrial aluminium rolling process steps to evaluate the interactions of different mechanisms taking place in the rolling processing chain, with a special attention to profile/flatness, surface and metal-lurgical properties.

scholarly journals The Analysis of the Asymmetric Plate Rolling Process in the Finishing Stand 3600/ Analiza Asymetrycznego Procesu Walcowania Blach Grubych W Klatce Wykańczającej 3600

2014 ◽  
Vol 59 (4) ◽  
pp. 1533-1538
Author(s):  
A. Kawałek ◽  
H. Dyja ◽  
M. Knapinski ◽  
G. Banaszek ◽  
M. Kwapisz
Keyword(s):  
Process Parameters ◽  
Rotational Speed ◽  
Shape Factor ◽  
Rolling Process ◽  
Asymmetry Factor ◽  
Asymmetric Rolling ◽  
Rolling Mills ◽  
Plate Rolling ◽  
Strip Shape ◽  
Roll Gap

Abstract In order to enhance the quality of plates, various solutions are being implemented, including normalizing rolling, the process of rolling followed by accelerated cooling, as well as new roll gap control systems. The hydraulic positioning of rolls and the working roll bending system can be mentioned here. The implementation of those systems results in increased loads of the rolling stands and working tools, that is the rolls. Another solution aimed at enhancing the cross-sectional and longitudinal shape of rolled plate is the introduction of asymmetric rolling, which consists in the intentional change of the stress and strain state in the roll gap. Asymmetric rolling systems have been successfully implemented in strip cold rolling mills, as well as in sheet hot rolling mills. The paper present results of studies on the effect of roll rotational speed asymmetry and other rolling process parameters on the change in the shape of rolled strip and the change of rolls separating force for the conditions of normalizing rolling of plates in the finishing stand. The variable process parameters were: the roll rotational speed asymmetry factor, av; the strip shape factor, h0/D; and the relative rolling reduction, ε. Working rolls of the diameter equal to 1000 mm and a constant lower working roll rotational speed of n = 50 rpm were assumed for the tests. The asymmetric rolling process was run by varying the rotational speed of the upper roll, which was lower than that of the lower roll. The range of variation of the roll rotational speed factor, av =vd/vg, was 1.01÷1.15. A strip shape factor of h0/D = 0.05÷0.014 was assumed. The range of rolling reductions applied was ε = 0.08÷0.50. The material used for tests was steel of the S355J2G3 grade. For the simulation of the three-dimensional plastic flow of metal in the roll gap during the asymmetric hot rolling of plates, the mathematical model of the FORGE 2008 ® program was used. For the mathematical description of the effect of rolling parameters on the strip curvature and rolls separating force the special multivariable polynomial interpolation was used. This method of tensor interpolation in Borland Builder programming environment was implemented. On the basis of the carried out analysis can be state, that by using the appropriate relative rolling reduction and working roll peripheral speed asymmetry factor for a given feedstock thickness (strip shape ratio) it is possible to completely eliminate the unfavorable phenomenon of strip bending on exit from the roll gap, or to obtain the permissible strip curvature which does not obstructs the free feed of the strip to the next pass or transferring the plate to the accelerated plate cooling stations. Additionally by introducing the asymmetric plate rolling process through differentiating working roll peripheral speeds, depending on the asymmetry factor used, the magnitude of the total roll separating force can be reduced and, at the same time, a smaller elastic deflection of rolling stand elements can be achieved. As a result smaller elastic deflection of the working rolls, smaller dimensional deviations across its width and length finished plate can be obtained.

scholarly journals IMPROVING DYNAMIC REGIME OF ROLLING FOR INCREASING DURABILITY OF BALL-ROLLING MILL ROLLS

2019 ◽  
Vol 61 (12) ◽  
pp. 927-932 ◽  
Author(s):  
V. Yu. Rubtsov ◽  
O. I. Shevchenko ◽  
M. V. Mironova
Keyword(s):  
Contact Pressure ◽  
Rotational Speed ◽  
Rolling Mill ◽  
Experimental Studies ◽  
Rolling Process ◽  
Operating Conditions ◽  
Frequency Method ◽  
Rolling Mills ◽  
Ball Rolling ◽  
Progressive Technology

One  of  the  important  reasons  for  the  downtime  of  ball  rolling  mills  is  replacement  of  rolls  due  to  their  wear  and  tear.  The  degree  and  zones  of  critical  wear  of  ball  rolling  rolls  are  investigated  in  the  article, where the greatest wear is observed over the flanges in zone of billet  capture.  Conditions  necessary  to  capture  the  blank  and  to  perform  rolling  process  are  analytically  determined.  Variable  frequency  method  of  roll  rotations  is  proposed  as  a  progressive  technology  for  blank supply. The results of tests for its variations in accordance with  linear  and  quadratic  law  are  presented.  Known  formulas  determining  average  strain  rate  at  rolls  rotational  speed  change  are  converted  for  linear and quadratic dependences. Experimental studies have been carried  out  in  conditions  of  EVRAZ  Nizhnetagilsky  Metallurgical  Plant  ball rolling mills during rolling of 60mm ball made of Sh-3G steel. Experiments  were  performed  for  given  parameters  of  manual  change  in  rolls rotation speed at blank capture by rollers. The results have shown  a  significant  effect  of  change  in  rotational  speed  on  average  specific  pressure during blank capture. Evaluation of torque-time and average  contact  pressure  for  calculated  and  experimental  data  are  presented.  Empirical characteristics are also described at variable rotational speed  of rolls according to linear and quadratic law. Acceptable convergence  of results of calculated and empirical characteristics is determined. Engineering solution has been proposed for that task. It consists in installation of a thyristor converter. This solution allows reduction of rolls  speed before blank capture. Also, this solution will increase frequency  to  the  nominal  value  according  to  the  given  law  after  blank  capture.  As an obtained result, there is uniform distribution of average contact  pressure over the entire length of the roll under different operating conditions  of  mill  in  automatic  mode. Application  of  this  technique  will  reduce wear degree of the rolling tool. At the same time, productivity  of ball rolling mill will be maintained. Rolls consumption and number  of rolls change will decrease due to rolls wear.

Intrinsic Hybrid Composites for Lightweight Structures: New Process Chain Approaches

2016 ◽  
Vol 1140 ◽  
pp. 239-246 ◽  
Author(s):  
Simon Frederik Koch ◽  
Daniel Barfuss ◽  
Mathias Bobbert ◽  
Lukas Groß ◽  
Raik Grützner ◽  
...  
Keyword(s):  
Hybrid Composites ◽  
Process Chain ◽  
Lightweight Structures ◽  
Fiber Placement ◽  
Reinforced Plastics ◽  
Steel Sheets ◽  
Process Chains ◽  
New Process ◽  
Hybrid Laminates ◽  
Automated Fiber Placement

This publication describes new process chain approaches for the manufacturing of intrinsic hybrid composites for lightweight structures. The introduced process chains show a variety of different part and sample types, like insert technology for fastening of hollow hybrid shafts and profiles. Another field of research are hybrid laminates with different layers of carbon fiber reinforced plastics stacked with aluminum or steel sheets. The derived process chains base on automated fiber placement, resin transfer molding, deep drawing, rotational molding and integral tube blow molding.

Systematic Process Chain Creation for CFRP Structures in Early Product Development Stages

2016 ◽  
Vol 1140 ◽  
pp. 328-334
Author(s):  
Matthias Behr ◽  
Carsten Schmidt
Keyword(s):  
Composite Structures ◽  
Production Costs ◽  
Preliminary Design ◽  
Process Chain ◽  
Whole Process ◽  
Reinforced Plastic ◽  
Building Process ◽  
Process Chains ◽  
Carbon Fibre Reinforced Plastic ◽  
Specific Sequences

A planning method is presented which allows to systematically building process chains based on a preliminary design of composite structures. The method utilises the specific sequences of procedural steps that occur in the production of carbon fibre reinforced plastic (CFRP) structures, to build sub process chains for each component of the structure. Process restrictions are considered to evaluate the suitability of different production processes. To obtain the whole process chain of the structure, different joining methods are applied in addition to combine the components and its sub process chains. The results of the presented method are used in an overarching development procedure to investigate resulting impacts on the solution. Possible impacts could be the production costs or the material characteristics.

scholarly journals Skew Rolling of Rods from Scrap Rail Heads

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2970 ◽  
Author(s):  
Tomczak ◽  
Pater ◽  
Bulzak
Keyword(s):  
Experimental Tests ◽  
Rolling Process ◽  
Industrial Applications ◽  
Experimental Investigations ◽  
Longitudinal Rolling ◽  
Rolling Mills ◽  
Second Stage ◽  
New Process ◽  
Skew Rolling ◽  
Theoretical Considerations

This paper presents the results of theoretical and experimental investigations of a new process of rolling rods from scrap rail heads. First, the industrial applications of scrap railway rails and methods of their recycling are discussed, and then the concept of two-stage rolling of rods from heads cut off from scrap rails is proposed. In the first stage of the process, a rail head preform was rolled in a hexagonal pass of a longitudinal rolling mill. Then in the second stage, the hexagonal bar was skew rolled into a rod in a helical roll pass. Theoretical considerations were based on finite element numerical modelling. The rolling process was simulated under 3D deformation using Forge NxT v.1.1 software developed by Transvalor Company. Calculations were carried out to determine the material flow kinematics, strength, and thermal parameters of the process and to identify the phenomena that might constrain its implementation. The numerical results were verified in experimental tests, during which preforms and rods were formed from scrap rail heads. The tests were conducted in longitudinal and skew rolling mills. The results indicate that rods can be effectively formed from scrap rail heads in just two steps. Rods obtained using the proposed method can be used as full-featured, semifinished products for the manufacture of various types of machine parts.

scholarly journals Silicon Steel Strip Profile Control Technology for Six-High Cold Rolling Mill with Small Work Roll Radius

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 401
Author(s):  
Hainan He ◽  
Jian Shao ◽  
Xiaochen Wang ◽  
Quan Yang ◽  
Xiawei Feng
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Steel Strip ◽  
Work Roll ◽  
Rolling Process ◽  
Silicon Steel ◽  
Cold Rolling Mill ◽  
Strip Profile ◽  
Profile Control ◽  
Small Work

Due to the requirement of magnetic properties of silicon steel sheets, producing high-precision size strips is the main aim of the cold rolling industry. The tapered work roll shifting technique of the six-high cold rolling mill is effective in reducing the difference in transverse thickness of the strip edge, but the effective area is limited, especially for a high crown strip after the hot rolling process. The six-high mill with a small work roll size can produce a strip with higher strength and lower thickness under a smaller rolling load. At the same time, the profile of the strip can be substantially improved. By advancing a well-established analytical method, a series of simulation analyses are conducted to reveal the effectiveness of a small work roll radius for the strip profile in the six-high cold rolling process. Through the analysis of flattening deformation and deflection deformation on the load, the change rule of the strip profile produced by the work roll with a small roll diameter can be obtained. Combined with theoretical analysis and industrial experiments, it can be found that the improvement effect of the small work roll radius on the profile of the silicon strip is as significant.

scholarly journals A deep q-learning-based optimization of the inventory control in a linear process chain

2020 ◽  
Author(s):  
M.-A. Dittrich ◽  
S. Fohlmeister
Keyword(s):  
Inventory Control ◽  
Data Exchange ◽  
Linear Process ◽  
Process Chain ◽  
Production Networks ◽  
Initial State ◽  
Q Learning ◽  
Reward Function ◽  
Decision Optimization ◽  
Process Chains

AbstractDue to growing globalized markets and the resulting globalization of production networks across different companies, inventory and order optimization is becoming increasingly important in the context of process chains. Thus, an adaptive and continuously self-optimizing inventory control on a global level is necessary to overcome the resulting challenges. Advances in sensor and communication technology allow companies to realize a global data exchange to achieve a holistic inventory control. Based on deep q-learning, a method for a self-optimizing inventory control is developed. Here, the decision process is based on an artificial neural network. Its input is modeled as a state vector that describes the current stocks and orders within the process chain. The output represents a control vector that controls orders for each individual station. Furthermore, a reward function, which is based on the resulting storage and late order costs, is implemented for simulations-based decision optimization. One of the main challenges of implementing deep q-learning is the hyperparameter optimization for the training process, which is investigated in this paper. The results show a significant sensitivity for the leaning rate α and the exploration rate ε. Based on optimized hyperparameters, the potential of the developed methodology could be shown by significantly reducing the total costs compared to the initial state and by achieving stable control behavior for a process chain containing up to 10 stations.

Heuristic-Based Evaluation of Energy Flows in Press Hardening Process Chains

2011 ◽  
Vol 473 ◽  
pp. 816-823 ◽  
Author(s):  
Reimund Neugebauer ◽  
Frank Schieck ◽  
Angela Göschel ◽  
Julia Schönherr
Keyword(s):  
Qualitative Evaluation ◽  
Resource Efficiency ◽  
Process Chain ◽  
Press Hardening ◽  
Whole Process ◽  
Quantitative Calculation ◽  
Hardening Process ◽  
Energy Flows ◽  
Process Chains ◽  
The Press

Energy and resource efficiency is a pressing issue for technological markets in the 21st century. In the field of production technology the development of energy and resource efficient processes and process chains is of particular importance. In order to meet these needs sustainable methods and standards have to be developed. This paper presents a new procedure to calculate and evaluate the energy and resource efficiency of process chains. The method consists of 4 stages that proceed from the real world to the quantitative calculation and qualitative evaluation of material and energy flows. The method is explained and validated using press hardening process chains as an example. The procedure enables the user to systematically capture and structure the press hardening process chain and subsequently develop a comprehensive model of the whole process chain. As a result, it allows to calculate the energy requirements for each stage of the process chain, and later on the process chain as a whole. The intention of the developed procedure is to provide a tool to detect the most energy efficient variant from a range of possible process chains.

scholarly journals An Activity and Resource Advisory System for Manufacturing Process Chains Selection at the early Stage of Product Development

2013 ◽  
Vol 834-836 ◽  
pp. 1927-1931
Author(s):  
Jaya Suteja The ◽  
Prasad K.D.V. Yarlagadda ◽  
M. Azharul Karim ◽  
Cheng Yan
Keyword(s):  
Product Development ◽  
Production Process ◽  
Manufacturing Process ◽  
Early Stage ◽  
Process Chain ◽  
Advisory System ◽  
Process Chains ◽  
Manufacturing Process Chain

Designers need to consider both the functional and production process requirements at the early stage of product development. A variety of the research works found in the literature has been proposed to assist designers in selecting the most viable manufacturing process chain. However, they do not provide any assistance for designers to evaluate the processes according to the particular circumstances of their company. This paper describes a framework of an Activity and Resource Advisory System (ARAS) that generates advice about the required activities and the possible resources for various manufacturing process chains. The system provides more insight, more flexibility, and a more holistic and suited approach for designers to evaluate and then select the most viable manufacturing process chain at the early stage of product development.

Microfabrication of ceramics by rapid prototyping process chains

2003 ◽  
Vol 217 (1) ◽  
pp. 41-51 ◽  
Author(s):  
R Knitter ◽  
W Bauer ◽  
D Göhring
Keyword(s):  
Rapid Prototyping ◽  
Process Chain ◽  
Moulding Process ◽  
Pressure Injection ◽  
Functional Models ◽  
Process Chains ◽  
Ceramic Components ◽  
High Flexibility ◽  
Very High

Most shaping processes for ceramics are based on a powder technological moulding process using a negative mould and subsequent thermal compaction. Especially for prototypes and small-lot series of microcomponents, the outlay for moulds is the major costing factor. Therefore the use of rapid prototyping (RP) processes can decisively reduce the costs and time in product development of ceramic microcomponents. By combining the high resolution of, for example, stereolithography as an inexpensive and fast supply for master models with the high flexibility of low-pressure injection moulding, a rapid prototyping process chain (RPPC) has been established for the fabrication of micropatterned ceramic components as functional models or pre-production lots. This RPPC proved to have a very high moulding precision and accuracy in the submillimetre range, but also enables the fabrication of components with outer dimensions of several centimetres. Different RP techniques were investigated with regard to their suitability to be used as master models in the replication chain. The quality of the master models turned out to be of decisive significance for the quality and reproducibility of the ceramic mouldings.

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