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.

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.

Measuring and Quantifying the Surface-Roughness Anisotropy of Modeled and Industrially Produced Surfaces

2005 ◽  
Vol 6-8 ◽  
pp. 573-582 ◽  
Author(s):  
C.M. Wichern ◽  
W. Rasp
Keyword(s):  
Surface Roughness ◽  
Rolling Direction ◽  
Three Dimensional ◽  
Roughness Parameter ◽  
Orientation Angle ◽  
Textured Surface ◽  
Angular Orientation ◽  
Textured Surfaces ◽  
Average Roughness ◽  
Dimensional Surface

‘Three-dimensional surface profilometry’ when used for analysis and product specification reports roughness parameters that provide an average surface description over a relatively large area. Many commercial sheet steels are produced with special textured surfaces for tribological benefits or appearance benefits. These surfaces, as well as others, may demonstrate high levels of roughness anisotropy that is not quantifiable by simple three dimensional surface parameters. This anisotropy can play an important role in the surface appearance of the finished product and in the tribological behaviour during forming. The current work presents a method for quantifying surface-roughness features as a function of angular orientation with respect to rolling direction. The measurement methodology was applied to several model surfaces and one industrially produced electron-beam textured-surface (EBT). This methodology extracts multiple surface-height profiles of the same angular orientation from a single surface and calculates an average roughness parameter for the orientation angle based on the multiple profiles. Particularly interesting results were the large number of profiles necessary to obtain repeatable values for the roughness variation with respect to direction and the strong influence of surface feature size on the repeatability of said results. These results indicate that care must be taken when using a single extracted profile to represent a ‘three-dimensional’ surface.

Research on surface topography wear of textured work roll in cold rolling

2015 ◽  
Vol 67 (3) ◽  
pp. 269-275 ◽  
Author(s):  
Dong Xu ◽  
Jie Zhang ◽  
Hongbo Li ◽  
Jinsong Lu ◽  
Qingguo Fan ◽  
...  
Keyword(s):  
Cold Rolling ◽  
Surface Topography ◽  
Abrasive Particle ◽  
Work Roll ◽  
Rolling Process ◽  
Textured Surfaces ◽  
Wear Performance ◽  
Content Type ◽  
Wear Process ◽  
Rolling Surface

Purpose – The purpose of this paper is to build a transient wear prediction model of surface topography of textured work roll, and then to investigate the wear performance of different original textured surfaces. The surface topography of steel sheets is one of the most important surface quality indexes, which is inherited from the textured work rolls in cold rolling. Surface topography of work roll is obviously changing in the cold rolling process. However, surface topography is difficult to measure in the industry production process. Design/methodology/approach – This paper presents a numerical approach to simulate the wear process based on the mixed lubrication model of cold rolling interface developed by Wilson and Sheu (Sheu and Wilson, 1994). It is assumed that wear takes place at locations where the surfaces are in direct contact, and the volume is removed by an abrasive particle which is an abstract concept based on the wear phenomenon of textured work roll. At each simulation cycle, the distribution of the contact pressure is calculated by the lubrication model. The material is removed by an abstract abrasive particle and the surface topography is modified correspondingly. The renewed surface topography is then used for the next cycle. Findings – Through comparative analysis, it can be found that the simulation results possess similar statistical characteristic with the measured data. A set of roughness parameters such as the amplitude, spacing and frequency-domain characteristics are introduced to analyze the wear performance of different textured surfaces. Numerical examples show that the surface topography has a significant effect on the wear performance of work roll in cold rolling. Originality/value – The proposed model can accurately predict the wear process of the surface topography in the cold rolling process, which provides the foundation for optimization of original surface topography of textured work roll. The model can also be considered as a tool applicable for research on control of the surface topography of steel strip in the cold rolling process.

Optimizing of Electric Discharge Texturing Parameters of Rolls of the Rolling Mill of Steel Sheets

2013 ◽  
Vol 420 ◽  
pp. 78-84 ◽  
Author(s):  
Emil Evin ◽  
Jozef Kmec ◽  
Erika Fechová
Keyword(s):  
Electric Discharge ◽  
Rolling Mill ◽  
Roughness Parameter ◽  
Good Adhesion ◽  
Factors Affecting ◽  
Reliability Indices ◽  
Steel Sheets ◽  
Study Results ◽  
Surface Microgeometry ◽  
Work Rolls

The producers of components require that cuts of steel sheets for superficial parts of cars would have guaranteed surface microgeometry, minimum defects, homogenous surface over the full width and length of the belt, mat appearance, good adhesion of the Zn layer. Microgeometry of the surface of galvanized sheets for superficial parts of cars is one of the decisive factors affecting the appearance of the surface after painting and stampability of steel sheets. Requirements for microgeometry are mainly focused on the roughness parameters Ra [μm] (roughness), Pc [cm-1] (number of peaks) or Wa [μm] (undulation roughness). This paper presents the study results of the influence of selected parameters of electric discharge texturing of rolls of the rolling mill on the Ra roughness parameter and number of peaks. Reliability of the process of electric discharge texturing of work rolls was assessed according to Cpm and Cp reliability indices. Dependencies on electric discharge texturing were depicted to predict Raand Pc qualitative indices of roughness.

Wettability of laser textured surface: a parametric study based on numerical simulation and experimentation

2018 ◽  
Vol 70 (6) ◽  
pp. 977-983 ◽  
Author(s):  
Yunlong Jiao ◽  
Xiaojun Liu ◽  
Kun Liu
Keyword(s):  
Surface Topography ◽  
Quantitative Research ◽  
Surface Characterization ◽  
Surface Texturing ◽  
Three Dimensional ◽  
Laser Surface Texturing ◽  
Dynamics Simulation ◽  
Textured Surface ◽  
Content Type ◽  
Characterization Methods

PurposeDynamic spreading and wetting on the rough surfaces is complicated, which directly affects the fluxion and phrase transition properties of the fluid. This paper aims to enhance our knowledge of the mechanism of micro-texture lubrication from interface wettability and provide some guidance for the practical manufacturing of the surfaces with special wettability and better lubrication characteristics.Design/methodology/approachThe effect of surface topography on the wetting behavior of both smooth and rough hydrophilic surfaces was investigated using a combination of experimental and simulation approaches. Four types of patterns with different topographies were designed and fabricated through laser surface texturing. The samples were measured with a non-contact three-Dimensional (3D) optical profiler and were parameterized based on ISO 25178. Quantitative research on the relevancy between the topography characteristic and wettability was conducted with several 3D topography parameters.FindingsResults show that for the surfaces with isotropic textures, topography with a small skewness (Ssk) and a large kurtosis (Sku) exhibits better wettability and spreading behavior. For the surfaces with anisotropic textures (smaller texture aspect ratio,Str), dominant textures (such as long groove, rectangle) play a significant guiding role in promoting spreading. In addition, the moving mechanism of the triple contact line and anisotropic spreading were also studied using a computational fluid dynamics simulation. The simulation results have a good adherence with the experimental results.Originality/valueMost of the surface characterization methods at present remain at a level that is related to geometric description, and the topography parameters are limited to 2D roughness parameters. So in present study, the relevancy between wettability and 3D surface topography parameters is explored. The authors believe that the current work provides a new viewpoint to the relevancy between surface topography and wettability.

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.

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.

Finite Element Analysis of Temperature and Crown of Rolls in Hot Strip Rolling

2009 ◽  
Vol 16-19 ◽  
pp. 575-579 ◽  
Author(s):  
Da Le Sun ◽  
Jian Guo Zhao ◽  
Liang Yu Chen
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Work Roll ◽  
Hot Strip Rolling ◽  
Strip Rolling ◽  
Element Analysis ◽  
Rolling Mills ◽  
Hot Strip ◽  
Thermal Crown ◽  
Work Rolls

In this paper a three-dimensional numerical computation on temperature and crown of rolls in hot strip rolling was evaluated based on finite element method and parallel computation technology with multiple CPUs. A comparison between calculated results and actual data collected from rolling mills was presented, which indicated the high accuracy of the model. The calculated results indicated that a significant impact in thin layer of work roll surface was brought by thermal load, while much weaker in the core. Furthermore, the temperature field and thermal crown of hot mill work rolls would reach a stabilized condition only when several rolling cycle be finished.

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