scholarly journals Skin Pass Rolling of High Manganese Steels

2016 ◽  
Vol 854 ◽  
pp. 93-98
Author(s):  
Kai Köhler ◽  
Norbert Kwiaton ◽  
Martin Bretschneider
Keyword(s):  
Surface Texture ◽  
Rolling Force ◽  
Work Roll ◽  
Major Influence ◽  
Roll Surface ◽  
High Manganese ◽  
Steel Sheets ◽  
Skin Pass ◽  
Texture Parameters ◽  
Work Rolls

Applying a specific roughness on steel sheets, to ensure paintability and sufficient lubrication, is a crucial point for the metal forming processes. Due to the strength of high manganese HSD® steels (X70MnAlSi 15-2.5-2.5), special actions are necessary to obtain the required roughness. At Salzgitter Mannesmann Forschung GmbH skin-pass rolling experiments on high manganese HSD® steels with different PRETEX® textured work-rolls were performed to investigate the influence of roll-surface-texture and skin-pass rolling force on the roughness transfer. The roughness and texture parameters of the steel sheets and roll surfaces were determined using optical confocal microscopy measurements. It is clearly shown that the work-roll surface texture has a major influence on the roughness transfer from work-rolls to steel sheet surfaces.

The change of work roll surface topography during skin pass rolling of steel sheets

2015 ◽  
Vol 67 (6) ◽  
pp. 606-611 ◽  
Author(s):  
Marek Burdek
Keyword(s):  
Surface Topography ◽  
Three Dimensional ◽  
Roughness Parameter ◽  
Work Roll ◽  
Roll Surface ◽  
Average Roughness ◽  
Content Type ◽  
Steel Sheets ◽  
Skin Pass ◽  
Work Rolls

Purpose – This paper aims to analyze changes in the surface topography of the work rolls during skin passing. Cold rolled steel sheets are additionally subject to skin pass rolling to form an appropriate surface topography. This operation should facilitate the process of further metal forming of steel sheets, such as deep drawing, painting, etc. The surface topography of steel sheets is determined by the surface topography of the work rolls as well as the skin pass rolling parameters (rolling speed, elongation, roll force, etc.). Suitable preparation and selection of roll surface topography influences the degree of rolls wear and the surface topography of steel sheets as well. Design/methodology/approach – Two-dimensional (2D) and three-dimensional (3D) roughness measurements of work roll surface before, during and after finishing of skin pass rolling of steel sheets are presented in the paper. The measurements were performed on four sets of work rolls with different surface topography. Findings – The appearance of the surface of rolls obtained from the analysis of 3D roughness, the values of selected parameters of the 3D roughness and relative changes of the roughness parameter Ra/Sa depending on the length of the skin passed steel sheets are presented. Practical implications – The wear of rolls is different depending on work surface topography. Originality/value – The aim of this paper is to analyze changes in the surface topography of the work rolls during skin passing. It was expected that the surface of work rolls with more summits at similar average roughness Ra will change much faster than the surface with fewer summits. For this purpose, preliminary tests were performed in an industrial environment on four pairs of work rolls, including two pairs of rolls that were hard chromium-plated.

Mechanics of Asymmetric Rolling of Thin Strip with Effect of Work Roll Edge Contact

2007 ◽  
Vol 561-565 ◽  
pp. 115-118
Author(s):  
Zheng Yi Jiang ◽  
Hai Bo Xie ◽  
L.M. Yang ◽  
Hong Tao Zhu ◽  
Dong Bin Wei ◽  
...  
Keyword(s):  
Rolling Force ◽  
Work Roll ◽  
Contact Length ◽  
Thin Strip ◽  
Asymmetric Rolling ◽  
Edge Contact ◽  
Roll Bending ◽  
Work Rolls ◽  
Strip Crown ◽  
Small Work

Asymmetric rolling of thin strip has become important due to a significant decrease of rolling force, which contributes to obtain the extremely thin strip, to reduce the rolling passes, and to save the energy by a decrease of anneal treatment. In asymmetric rolling of thin strip, edges of work rolls may contact and deform when no or small work roll bending force is applied. Work roll edge contact forms a new deformation feature. In this paper, the effects of initial thickness of strip and friction coefficient on the rolling pressure, roll edge contact length and strip crown during asymmetric rolling of thin strip with work roll edge contact effect has been discussed, and the calculated rolling force with work roll edge contact is compared with the measured value.

An Investigation of the Effect of Speeds of Work Rolls on Rolling Strip

1995 ◽  
Vol 117 (3) ◽  
pp. 341-346 ◽  
Author(s):  
Zone-Ching Lin ◽  
Y. C. Cheng
Keyword(s):  
Hot Rolling ◽  
Rolling Force ◽  
Large Strain ◽  
Work Roll ◽  
Rolling Process ◽  
Analysis Model ◽  
Hot Rolling Process ◽  
Rolling Strip ◽  
Work Rolls ◽  
Thermoelastic Plastic

The paper is an investigation of strip curvature caused by the different speeds between the upper work roll and the lower work roll in the rolling process for an aluminum strip. At the same time, we analyzed the variations in the temperature field and strain field, and used a method of speeds variation of the upper and lower work rolls to calibrate the deformation curvature caused by the coolant condition in the hot rolling process. Based on the large deformation-large strain theory, and by means of the Updated Lagrangean Formulation (ULF) and increment theory, a coupled thermoelastic-plastic analysis model for hot rolling process is thus constructed. At the same time the finite difference method was also used to solve the transient heat transfer equation. Finally, the numerical analysis method developed in this study was employed to analyze the changes in the aluminum strip’s temperature and other changes during rolling. In addition, the average rolling force obtained from the simulation was compared with that from the experiments. It verified that the model in this study is reasonable.

scholarly journals On the Evolution of Temperature and Combined Stress in a Work Roll under Cyclic Thermo-Mechanical Loadings during Hot Strip Rolling and Idling

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5054
Author(s):  
Kejun Hu ◽  
Qinghe Shi ◽  
Wenqin Han ◽  
Fuxian Zhu ◽  
Jufang Chen
Keyword(s):  
Thermal Stress ◽  
Hot Rolling ◽  
Work Roll ◽  
Rolling Process ◽  
Roll Surface ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Hot Strip ◽  
Calculation Results ◽  
Work Rolls

An accurate prediction of temperature and stress evolution in work rolls is crucial to assess the service life of the work roll. In this paper, a finite element method (FEM) model with a deformable work roll and a meshed, rigid body considering complex thermal boundary conditions over the roll surface is proposed to assess the temperature and the thermal stress in work rolls during hot rolling and subsequent idling. After that, work rolls affected by the combined action of temperature gradient and rolling pressure are investigated by taking account of the hot strip. The accuracy of the proposed model is verified through comparison with the calculation results obtained from the mathematical model. The results show that thermal stress is dominant in the bite region of work rolls during hot rolling. Afterwards, the heat treatment residual stresses which are related to thermal fatigue are simulated and introduced into the work roll as the initial stress to evaluate the redistribution under the thermal cyclic loads during the hot rolling process. Results show that the residual stress significantly changed near the roll surface.

scholarly journals Improving Thin Strip Profile Using Work Roll Cross and Work Roll Shifting Methods in Cold Strip Rolling

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Hasan Tibar ◽  
Zhengyi Jiang
Keyword(s):  
Rolling Force ◽  
Work Roll ◽  
Strip Width ◽  
Thin Strip ◽  
Speed Ratio ◽  
Strip Rolling ◽  
Strip Shape ◽  
Strip Profile ◽  
Work Roll Shifting ◽  
Work Rolls

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.

A Study on Corrosion Wear of Cold Rolling Work Roll

2013 ◽  
Vol 871 ◽  
pp. 152-158
Author(s):  
Wei Hua Sun ◽  
Hong Chun Li ◽  
Ahn Kiet Tieu
Keyword(s):  
Cold Rolling ◽  
Corrosive Wear ◽  
Work Roll ◽  
Rolling Process ◽  
Corrosion Wear ◽  
Roll Surface ◽  
Steel Rolling ◽  
Conductive Medium ◽  
Materials Used ◽  
Work Rolls

The MMS-2B wear machine was used to study abrasion wear of work rolls in cold rolling by simulating emulsion cooling during the cold rolling process. The work roll materials used were 4%Cr, same as those in industrial production. The surface SEM scanning photographs were taken every 30 minutes until the friction experiment finished, and erosive appearance of emulsion on the work roll surface could be seen in the photos. The corrosive wear of the work roll surface is discussed. Findings show that the main causes of stress corrosion and pitting corrosion are uneven microstructure on the work roll surface and a large number of dislocation accumulations, which form microscopic cells. Water in steel rolling emulsion is the main conductive medium of electrochemistry reaction, and this intensifies the corrosive wear.

Surface Roughness and Wear of Work Roll Containing Ti in Cold Strip Rolling

2008 ◽  
Vol 32 ◽  
pp. 157-160 ◽  
Author(s):  
H.C. Li ◽  
Zheng Yi Jiang ◽  
A. Kiet Tieu ◽  
Wei Hua Sun ◽  
Hei Jie Li ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Lower Surface ◽  
Work Roll ◽  
Roll Surface ◽  
Strip Rolling ◽  
Wear Process ◽  
Roll Wear ◽  
Work Rolls ◽  
Cold Strip Rolling

The consumption of work rolls in cold strip mills is significant. One of the key issues for work rolls is the surface roughness which affects the rolling stability and surface finish of the strip. The produced strip has lower surface finish if the roll surface roughness is large. However, if the roll surface roughness is small, it is not helpful for establishing the rolling process, which will reduce the productivity. In this case, a laser treatment is employed to increase the value of roll surface roughness. In order to reduce the times of roll grinding, the cold strip mill and roll manufacturers have developed new types of rolls such as the rolls containing Ti to increase the roll wear resistance in cold strip rolling. Results show that the new 4CrTi roll has a significant advantage of preventing decrease of the roll surface roughness. The size and generation of particles during roll wear process and the effect of Ti on roll wear have been discussed.

Surface texture transfer in skin-pass rolling with the effect of roll surface wear

Wear ◽  
2021 ◽  
pp. 203764
Author(s):  
Chuhan Wu ◽  
Liangchi Zhang ◽  
Peilei Qu ◽  
Shanqing Li ◽  
Zhenglian Jiang ◽  
...  
Keyword(s):  
Surface Texture ◽  
Surface Wear ◽  
Roll Surface ◽  
Skin Pass ◽  
Texture Transfer

scholarly journals Analysis of thin strip profile by work roll crossing and shifting in asymmetrical cold rolling

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540032 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zhengyi Jiang ◽  
Dongbin Wei
Keyword(s):  
Cold Rolling ◽  
Rolling Mill ◽  
Rolling Force ◽  
Work Roll ◽  
Thin Strip ◽  
Asymmetrical Rolling ◽  
Strip Profile ◽  
Work Rolls

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.

Mechanics of a Special Asymmetric Rolling of Thin Strip

2007 ◽  
Vol 340-341 ◽  
pp. 707-712 ◽  
Author(s):  
Zheng Yi Jiang ◽  
Hong Tao Zhu ◽  
Dong Bin Wei ◽  
A. Kiet Tieu
Keyword(s):  
Rolling Mill ◽  
Rolling Force ◽  
Work Roll ◽  
Contact Length ◽  
Thin Strip ◽  
Rolled Strip ◽  
Initial Thickness ◽  
Asymmetric Rolling ◽  
Edge Contact ◽  
Work Rolls

Asymmetric rolling is used to produce thinner strip, which can reduce rolling force significantly. When a thinner strip is rolled on a rolling mill, work roll edge may contact each other, which affects the mechanics of this special asymmetric rolling and the crown of the rolled strip. In this paper, the authors developed a numerical model to simulate this special rolling and obtained the rolling force, intermediate force, roll edge contact force, the crown of the rolled strip and the edge contact length. The effects of the initial thickness of strip and the friction variation at upper and lower work rolls on the rolling force and crown of the rolled strip are also discussed.

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