Reproduction and Deformation Characteristics of Oxide Scale in Hot Rolling Using Vacuum Rolling Mill

2011 ◽  
Vol 696 ◽  
pp. 150-155 ◽  
Author(s):  
Akio Segawa
Keyword(s):  
Oxide Scale ◽  
Hot Rolling ◽  
Rolling Mill ◽  
Surface Defect ◽  
Rolling Process ◽  
Sheet Surface ◽  
Hot Rolling Process ◽  
Hot Rolling Mill ◽  
Transfer Method ◽  
Vacuum Hot Rolling

There is fear that the oxide scale formed in hot rolling causes adverse effects for surface properties of final product. In hot rolling, the sheet surface is occurred reoxidation after descaling. Therefore, the oxide scale is rolled together, and causes the surface defect. In this study, the method for reproducing the oxide scale in hot rolling is proposed by a vacuum hot rolling mill, named the scale transfer method, and focused on the deformation of the oxide scale itself. As the results, it’s possible to reproduce the oxide scale in the actual hot rolling process. It showed that causes the new surface defect for invading the oxide scale in the sheet surface during roll bite.

Numerical Simulation on Correcting Camber and Wedge of Steel Slabs in Hot Rolling Mill

2014 ◽  
Vol 626 ◽  
pp. 570-575 ◽  
Author(s):  
Jong Ning Aoh ◽  
Han Kai Hsu ◽  
Wei Ting Dai ◽  
Chun Yen Lin ◽  
Yen Liang Yeh
Keyword(s):  
Hot Rolling ◽  
Rolling Mill ◽  
Rolling Direction ◽  
Rolling Process ◽  
Element Analysis ◽  
Hot Rolling Process ◽  
Steel Slab ◽  
Hot Rolling Mill ◽  
Rolling Load

In the hot rolling process, the steel slab may experience a temperature gradient along its transverse direction which may cause camber and wedge after rolling. Camber and wedge phenomenon will affect the quality of the steel plate. To eliminate camber and wedge phenomenon, a pair of side guides is placed before and behind the hot rolling mill. The position mode and the force mode are the control modes for side guides to correct the slab shape and to guide the slab to follow rolling direction. Finite element analysis using ABAQUS was applied to simulate hot rolling process to find the correction mechanism of rolling equipment. The centerline of slab was traced and the shape of slab was predicted. The difference of rolling load between work side and drive side of roller was determined. Furthermore, the load, stress and velocity distribution on the slab at roll bite were analyzed. By using numerical model, hot rolling parameters including side guide control strategy can be predicted, which can provide the hot rolling line as a guideline to improve the quality of the steel slab.

scholarly journals Thermal properties of oxide scale on surface of work roll in hot rolling mill

2018 ◽  
Vol 15 ◽  
pp. 59-64 ◽  
Author(s):  
Nobuki Yukawa ◽  
Eiji Abe ◽  
Shohei Fujiwara
Keyword(s):  
Thermal Properties ◽  
Oxide Scale ◽  
Hot Rolling ◽  
Rolling Mill ◽  
Work Roll ◽  
Hot Rolling Mill

Deformation and Fracture Behavior of Surface Oxide Scale on Fe-13Cr Alloy in Hot-Rolling Process

2006 ◽  
Vol 522-523 ◽  
pp. 461-468 ◽  
Author(s):  
Y. Hidaka ◽  
T. Anraku ◽  
Nobuo Otsuka
Keyword(s):  
Oxide Scale ◽  
Hot Rolling ◽  
Reduction Rate ◽  
Rolling Process ◽  
Surface Oxide ◽  
Rolling Reduction ◽  
Outer Scale ◽  
Hot Rolling Process ◽  
Micro Cracks ◽  
Inner Scale

The behavior of the surface oxide scale on steel products during hot rolling process influences the surface properties of final products. To investigate the deformation and the fracture behavior of surface oxide scale of Fe-13Cr alloy, a hot rolling test was carried out. The oxide scale rolled out was observed in detail by using TEM. The specimen was hot-rolled after oxidation at 1100 for 90 minutes in air. The hot rolling tests with two conditions (. The hot rolling test of the outer scale {=whole layer scale} , . The hot rolling test of the inner scale that removed the outer scale) were carried out. The rolling reduction rate was 25, 44, 58, and 68%. The outer scale was composed of Fe2O3 and F3O4, and the inner scale was composed of Fe3O4, FeCr2O4, and a small amount of Fe2SiO4. Fe2SiO4 formed along the grain boundaries of the other oxides (Fe3O4, FeCr2O4) was observed by TEM. In the test , Fe2O3 of the outer scale was pulverized to fine particle that looks like red powder, and Fe3O4 of the outer scale was cracked by hot rolling. A ductility-like behavior was observed in the inner scale (Test ). That is, it was found by the SEM observation that porosity and micro cracks of the surface oxide disappeared gradually according to the increase in the rolling reduction. It was thought that the porosity and the micro cracks eased the compression stress caused by hot rolling. In the case of high reduction rate, FeSi2O4 ,which is a low melting point oxide, formed on grain boundary caused grain boundary slipping. When the rolling reduction is very high, plastic deformation by dislocation occurred in Fe3O4 and FeCr2O4. However, these oxides were broken, when their plasticity would not be able to accept considerably high rolling reduction.

Thermo-Mechanical Coupled Analysis of Heavy Shell Ring Hot Rolling Mill with Two Drive Rolls

2012 ◽  
Vol 452-453 ◽  
pp. 200-205
Author(s):  
Jian Liang Sun ◽  
Hong Min Liu ◽  
Yan Peng ◽  
Gang Liu ◽  
Yan Liu
Keyword(s):  
Hot Rolling ◽  
Rolling Mill ◽  
Rolling Process ◽  
Ring Rolling ◽  
Coupled Analysis ◽  
Test Machine ◽  
Hot Rolling Mill ◽  
Shell Ring ◽  
Ring Rolling Mill ◽  
Ring Rolling Process

The heavy shell ring rolling mill which produces the large shell ring used in nuclear power, large-scale hydrogenation reactor and coal liquefaction reactor was taken as subject investigated. Because the size of shell ring is very large and the material of shell ring is special, the double drive rolls was taken in the shell ring rolling mill. Based on the elastic-plastic FEM and MARC software platform, the three dimensional thermal-mechanical coupled model of shell ring rolling process was built in this paper. First, the heat simulation text of the shell ring material has been carried out on the Gleeble-3500 thermal simulation test machine and the material properties were obtained. Then, considering the characteristics of heavy shell ring hot rolling mill with two drive rolls, the key problems such as geometry, material and thermo-boundary conditions were solved, the thermo-mechanical coupled finite element model of heavy shell ring hot rolling has been establised. At last, based on explicit dynamic FEM, the thermo-mechanical simulation of heavy shell ring rolling process was made. The stress field, strain field and temperature field were studied, the metal plastic deformation and its influence factors were investigated. The conclusions are agreement with the real rolling process. The conclusions are significant for designing equipments of shell ring rolling mill and developing new rolling schedule.

Utilization of Steelmaking and Hot-Rolling Mill Waste

2012 ◽  
Vol 260-261 ◽  
pp. 627-630
Author(s):  
Lian Chen
Keyword(s):  
Oxide Scale ◽  
Hot Rolling ◽  
Oxidation Rate ◽  
Rolling Mill ◽  
Carbon Oxidation ◽  
Hot Metal ◽  
Iron And Steel ◽  
Hot Rolling Mill ◽  
Mill Waste

Based on the composition and characteristics of steelmaking dry-dedusting dust and oxide scale in hot-rolling mill, cold briquetting ores were processed by dust and oxide scale, and applied to converter vanadium recover. The research results show that, hot metal carbon oxidation rate and vanadium oxidation rate increased with the increased use of cold briquetting ores, and the TFe content of vanadium slag reduced, the consumption of iron and steel materials decreased. Not only can effectively use the steelmaking mill and hot-rolling mill waste, but also can improve the product quality of the converter vanadium recover.

Modelling of the Development of Initial Crack under Hot Rolling Condition

2006 ◽  
Vol 505-507 ◽  
pp. 1291-1296 ◽  
Author(s):  
Jian Ning Tang ◽  
A. Kiet Tieu ◽  
Zheng Yi Jiang
Keyword(s):  
Oxide Scale ◽  
Hot Rolling ◽  
Crack Width ◽  
Steel Substrate ◽  
Rolling Process ◽  
Initial Crack ◽  
Strip Surface ◽  
Hot Rolling Process ◽  
Scale Layer ◽  
Materials Flow

An oxide scale layer is formed on the steel strip surface due to the high temperature (850-1100 °C) of the strip in hot rolling. The oxide scale layer may not be continuous because of the defects such as void existing in the layer before the strip enters the roll bite. The non-zero cracks may therefore be formed on the oxide scale layer, especially, when the oxide scale layer is relatively thick. These cracks may become narrower (even become closed) or wider (even form steel substrate extrusion) after hot rolling deformation. The development of the crack depends on the materials flow in the hot rolling process. The shape of the profile of the oxide scale layer has a significant effect on the materials flow in hot rolling process so it is important to investigate the effect of the oxide scale profile on the propagation of the crack. In this paper, the authors used the FEM method to simulate the crack propagation in oxide scale under hot rolling conditions for different profile parameters of the oxide scale layer. Simulation results indicate that the larger is the initial profiles surface roughness, the larger the crack width remained after rolling. With a rough profile and large initial crack width, the steel substrate extrusion may be formed.

Analysis of interconnections between technical systems on hierarchically connected technological levels of steel sheet production by hot rolling

2020 ◽  
Vol 76 (8) ◽  
pp. 847-855
Author(s):  
E. N. Shiryaeva ◽  
M. A. Polyakov ◽  
D. V. Terent'ev
Keyword(s):  
Hot Rolling ◽  
Systems Analysis ◽  
Rolling Mill ◽  
Steel Sheet ◽  
Technological System ◽  
Necessary Condition ◽  
Rolled Sheet ◽  
Technological Systems ◽  
Hot Rolling Mill ◽  
Technical Systems

Complexity of modern metallurgical plants, presence of great number of horizontal and vertical interactions between their various structural subdivisions makes it necessary to apply a systems analysis to elaborate effective measures for stable development of a plant operation. Among such measures, digitalization of a plant is widespread at present. To implement the digitalization it is necessary to have clear vision about links at all the levels of the technological system of a plant. A terminology quoted, accepted in the existing regulatory documents for defining of conceptions, comprising the technological system. It was shown, that the following four hierarchical levels of technological systems are distinguished: technological systems of operations, technological systems of processes, technological systems of production subdivisions and technological systems of plants. A hierarchical scheme of technological systems of hot-rolled sheet production at an integrated steel plant presented. Existing horizontal and vertical links between the basic plant’s shops shown. Peculiarities of flows of material, energy and information at the operation “rolling” of the technological system “hot rolling of a steel sheet” considered. As a technical system of the technological process of the hot rolling, the hot rolling mill was chosen. A structural diagram of the hot rolling mill was elaborated, the mill being consisted of reheating furnaces, roughing and finishing stand groups, with an intermediate roll-table between them, and down-coilers section. Since the rolling stands are the basic structural elements of the hot rolling mill, structural diagrams of a roughing and a finishing stands were elaborated. Results of the systems analysis of the technological and technical systems, hierarchically linked in the process of steel sheet hot rolling, can be applied for perfection of organization structure of the whole plant, as well as for elaboration mathematical models of a system separate elements functioning, which is a necessary condition for a plant digitalization.

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