Analysis of Thin Strip Shape and Profile in Cold Rolling: A Way to Improve Strip Profile and Mechanical Properties

2016 ◽  
Vol 879 ◽  
pp. 849-854 ◽  
Author(s):  
H.B. Tibar ◽  
Zheng Yi Jiang

Optimisation of the physical and mechanical properties of cold rolled thin strips is achieved by controlling the rolling parameters. In this paper, the factors affecting the low carbon steel thin strip profile of asymmetrical cold rolling have been studied at a speed ratio of 1.3 without lubricant applied. The effect of rolling parameters on the resulting microstructure was also investigated. It was found that under dry condition, work roll shifting and work roll cross angle can improve the strip profile, and the improvement is more significant with an increase of work roll cross angle rather than that of work roll shifting. A slight change in microstructure was evident with increasing work roll shifting values. In addition, effects of rolling parameters on the strip profile and microstructure have also been discussed.

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Hasan Tibar ◽  
Zhengyi Jiang

The optimization of rolling parameters in order to achieve better strip shape and to reduce rolling force is a challenge in rolling practice. In this paper, thin strip asymmetrical rolling of aluminum at various speed ratios under lubricated condition has been investigated at various combinations of work rolls cross (WRC) angles and work rolls shifting (WRS) values. The effects of strip width, reduction, and rolling speed on strip shape taking WRC and WRS into consideration are discussed. Results show that strip profile improves significantly when the WRC angle is increased from 0° to 1°, with an associated reduction in rolling force. Increasing WRS value from 0 to 8 mm improves the strip profile as well but not as significantly as when WRC angle is increased. No significant improvement was found in strip shape when the strip width was increased. At higher reduction, the strip shape was improved; a decrease in the rolling force was also observed. A higher speed ratio was found to be effective only at a higher WRC angle. The effect of lubrication on the strip profile was significant. Results indicate that an optimum combination of WRC, WRS, reduction, width, and speed ratio under lubricated conditions can ensure an improved exit strip profile, reduce rolling force, and obtain a better quality strip.


2017 ◽  
Vol 863 ◽  
pp. 323-327 ◽  
Author(s):  
Yustiasih Purwaningrum ◽  
Panji Lukman Tirta Kusuma ◽  
Dwi Darmawan

The aimed of this research is to investigate the effect of T-Joint’s root gap on physical and mechanical properties of weld metal. Low carbon steel were joined in T-joint types using MIG (Metal Inert Gas) with variation of root gap. The root gap used were 0 mm, 3 mm and 6 mm. The physical properties examined with chemical composition, microstructure and corrosion using optical microscope. The mechanical properties were measured with respect to the strength and hardness using Universal testing machine and Vickers Microhardness. The results show that the highest value found in welds with a gap of 3 mm with a value of 163.57 MPa. Hardness value is directly proportional to the tensile strength of the material. The highest value found in welds with root gap of 3 mm, followed by root gap of 6 mm, and 0 mm Hardness values in the welding area is higher than the parent metal and HAZ because the number of Si, Mn and Cu elements in the welding metals are bigger than base metal. Weld with all variation of root gap have a good corrosion resistance because the corrosion rate in welds with various root gap have a value below 0.02 mmpy. Microstructure of weld metals were Accicular ferrite, Widmanstatten ferrite, and grain boundary ferrite, while microstructure of base metal and HAZ were ferrite and perlite.


2015 ◽  
Vol 812 ◽  
pp. 315-320
Author(s):  
Enikö Réka Fábián ◽  
Áron Kótai

It have been studied the cold rolling effects on the microstructure of samples prepared from Al-killed low carbon steel sheets with high coiling temperatures. The microstructure of the hot rolled steels sheet is formed from ferrite and large carbides when the coiling temperature is high. The cold rolling affects the steel mechanical and electrochemical properties due to microstructural changes. We have studied the microstructure by optical microscope and scanning electron microscope. Low angles grain boundaries and the texture of samples were studied by EBSD method.


2013 ◽  
Vol 773-774 ◽  
pp. 70-78 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei ◽  
Xiao Dong Wang ◽  
Hasan Tibar

Controlling cold strip profile is a difficult and significant problem has been found in industry during thin strip rolling. At present choosing the new type of strip rolling mill is the one of main methods to control the strip shape quality in cold rolling. The influences of rolling process parameters such as the work roll cross angle and work roll shifting on the strip shape and profile of thin strip are recognised throughout this study. The results show that the roll crossing and shifting is efficient way to control the strip shape. The increase of the work roll crossing angle would lead to improve the strip profile significantly by decreasing the exit strip crown and edge drop. The strip profile would be enhanced if the axial roll shifting was increased. Moreover, the total rolling force was analysed in detail by changing the roll cross angle and axial shifting roll.


2014 ◽  
Vol 894 ◽  
pp. 212-216 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei

Strip profile control during rolling is required to assure the dimensional quality of rolled thin strip is acceptable for customers. Throughout rolling, the strip profile is controlled by using the advanced shape control rolling mill, such as the combination of work roll crossing and shifting during asymmetrical rolling, the one of the valuable methods to control the strip profile quality in rolling process. In this paper, the influences of cold rolling parameters such as the crossing angle and axial shifting value of work rolls on the strip profile are analysed. The strip shape control is discussed under both symmetrical and asymmetrical rolling conditions. The obtained results are appropriate to control the rolled thin strip profile in practice.


2016 ◽  
Vol 701 ◽  
pp. 187-194
Author(s):  
Phoumiphon Nordala ◽  
Radzali Othman ◽  
Ahmad Badri Ismail

In the present study, the effect of cold-rolling for the amount of reduction in thickness ranging from 25% to 75% on microstructure and mechanical properties of plain low carbon steel processed from dual-phase ferrite-martensite starting microstructure was studied. As the cold-rolling, the microstructure elongated to rolling direction and more compressed with increasing the rolling reduction and strength also increased. After annealing at warm temperature 500°C, the ultrafine grained was obtained in the 75% rolling reduction. Moreover, it was exhibited excellent strength of 82% and hardness of 66.1% higher than as-received condition with adequate uniform elongation 9.6%.


2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540032 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zhengyi Jiang ◽  
Dongbin Wei

In order to analyze the effects of cold rolling parameters such as the crossing angle and axial shifting value of work rolls on the strip profile, extensive tests were carried out on a 4-high rolling mill equipped with a work roll crossing and shifting system. The results show that the strip profile is nearly flat under asymmetrical rolling. The rolling force was also analyzed in detail by changing the crossing angle and axial shifting value of work rolls.


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