Rolling Temperature for Steel Hot Flat Rolled at Low Strain Rates

2009 ◽  
Vol 62-64 ◽  
pp. 317-323
Author(s):  
P.O. Aiyedun ◽  
S.A. Aliu
Keyword(s):  
Hot Rolling ◽  
High Strain ◽  
Geometric Mean ◽  
Rolling Temperature ◽  
Strain Rates ◽  
Averaging Methods ◽  
Flat Rolling ◽  
Experimental Values ◽  
Rolling Load ◽  
Rolling Temperatures

Different methods of obtaining averages have been used to determine mean rolling temperatures from measured temperatures of various specimens during roll contact in hot flat rolling. The obtained mean rolling temperatures were used in turn in hot rolling simulation programs based on Sims, and Bland and Ford’s theories for calculating rolling loads and torque during hot flat rolling of steels at low strain rates (0.08 – 1.5 s-1). The hot rolling Bland and Ford’s (HRBF) Theory and Sim’s Theory gave similar results when any of the averaging methods of temperature is used to calculate rolling load and torque at high strain rates (1.5 –500s-1). However at low strain rates HRBF gave closer approximations to experimental results. Comparing the results with experimental values, the harmonic mean was found to give the best mean rolling temperature for hot flat rolling simulation at low strain rates compared to geometric mean, arithmetic mean and root mean square.

Numerical Estimation of Rolling Load and Torque for Hot Flat Rolling of HCSS316 at Low Strain Rates Based on Mean Temperature

2016 ◽  
Vol 26 ◽  
pp. 11-29
Author(s):  
Taoheed O. Sadiq ◽  
Taiwo G. Fadara ◽  
Peter O. Aiyedun ◽  
Jamaliah Idris
Keyword(s):  
Hot Rolling ◽  
Carbon Steels ◽  
Rolling Temperature ◽  
Strain Rates ◽  
Numerical Estimation ◽  
Aisi Type ◽  
Flat Rolling ◽  
The Mean ◽  
Experimental Values ◽  
Rolling Load

Numerical estimation of rolling load and torque often showed large discrepancies when compared with experimental values. This was attributed to difficulty in estimating the mean rolling temperature from the available data. This work is thus directed at obtaining a good estimate for the mean rolling temperature which can effectively be used for load and torque estimates. Hot flat rolling stimulation by use of the Bland and Ford’s cold rolling (HRBF) theory confirmed the reverse sandwich effect in selected carbon steels at low strain rates. In this work, the effect of pass reduction on rolling temperature distribution, yield stress and rolling load were studied for AISI Type 316 stainless steel (HSCSS316). For this new simulation, at low and high strain rates, results showed that the ratio of experimental to calculated rolling load and torque were higher at lower reduction than at higher reduction. These results confirmed excess load and torque in the hot rolling of HSCSS316 low reductions. The results obtained from Hot Rolling Bland and Ford’s Theory based on Root Mean Square rolling temperature were in good agreement with values obtained using Reverse Sandwich Model and the Reverse Sandwich- Hot Rolling Bland and Ford’s Program under the same rolling conditions.

Effect of Pass Reduction on Rolling Parameters Using Reverse Sandwich Model Integrated into the Hot Rolling Bland and Ford’s Theory

2009 ◽  
Vol 62-64 ◽  
pp. 385-392
Author(s):  
O.J. Alamu ◽  
P.O. Aiyedun ◽  
Nurudeen O. Adekunle
Keyword(s):  
Hot Rolling ◽  
High Strain ◽  
Carbon Steels ◽  
Strain Rates ◽  
Torque Estimation ◽  
Aisi Type ◽  
Flat Rolling ◽  
Rolling Load ◽  
Excess Load ◽  
Sandwich Model

Hot flat rolling simulation by use of the Bland and Ford’s cold rolling (HRBF) theory confirmed the reverse sandwich effect in selected carbon steels at low strain rates. The Reverse Sandwich Model (RSM) was subsequently integrated into the HRBF theory for load and torque estimation. In this work, the effect of pass reduction on rolling temperature distribution, yield stresses and rolling load were studied for AISI Type 316 stainless steel (HCSS316). For this new simulation, at low and high strain rates, results showed that the ratio of experimental to calculated roll load and torque were higher at lower reduction than at higher reduction. These results confirmed excess load and torque in the hot rolling of HCSS316 at low reductions. This is in agreement with results obtained using Sim’s theory, HRBF theory and the RSM.

scholarly journals Influence of Rolling Temperatures on Interface Microstructure and Mechanical Properties of Multi-Pass Rolling TA1/Q235B Explosive Welded Sheets

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1654
Author(s):  
Huizhong Li ◽  
Liangming Cao ◽  
Xiaopeng Liang ◽  
Wending Zhang ◽  
Chunping Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Strength ◽  
Hot Rolling ◽  
Transition Layer ◽  
Rolling Temperature ◽  
Rolled Sheet ◽  
Interface Microstructure ◽  
Microstructure And Mechanical Properties ◽  
Rolling Temperatures

The effect of rolling temperatures on the interface microstructure and mechanical properties is investigated using 2-mm-thick TA1/Q235B composite sheets, which were prepared after nine passes of hot rolling of explosive welded plates. The results show that the vortex region and the transition layer exist in the interface at the explosive welded plate, while only the transition layer exists in the interface after hot rolling. The transition layer is composed of α-Ti, TiC, Fe, and FeTi, and the thickness increases with the increasing rolling temperature. The microhardness of the explosive welded plate is higher than that of the hot-rolling sheet, and the microhardness of interface are higher than that of matrix metals. The interface shear strength and tensile elongation of the hot-rolled sheet increase with the increasing hot rolling temperature, while the ultimate tensile strength (UTS), yield strength (YS) and Young modulus decrease with the increase of hot rolling temperature. The shear strength of sheets is related to the interfacial compounds, and the tensile strength is mainly affected by the grain morphology of the matrix.

Temperature changes in hot flat rolling of steels at low strain rates and low reduction

1997 ◽  
Vol 211 (4) ◽  
pp. 261-284 ◽  
Author(s):  
P O Aiyedun ◽  
L G M Sparling ◽  
C M Sellars
Keyword(s):  
Temperature Gradient ◽  
Rolling Temperature ◽  
Large Temperature ◽  
Specimen Thickness ◽  
Air Cooling ◽  
Strain Rates ◽  
Low Carbon ◽  
Temperature Changes ◽  
Flat Rolling ◽  
The Mean

A finite difference (two-dimensional) model developed to describe the heat flow at low strain rates (0.08–1.5 s−1) and low reduction (∼10 per cent) for a hot flat rolled slab both during air cooling and during roll contact has been used in conjunction with experimentally measured temperatures through specimen thickness during roll contact after reheating to temperatures in the range 1000–1200°C for mild steel, low carbon SS316 and high carbon SS316 (with Nb, V and Ti). At high strain rates (∼1.5 s−1) a steep temperature gradient was produced in the specimen near the surface whereas for low strain rates (∼0.08 s−1) this temperature gradient penetrated deep into the thickness, leading to a large drop in the mean rolling temperature. Roll chilling, leading to higher values of the Zener-Holloman parameter, Z, resulted from a decrease in the mean rolling temperature and the large temperature gradient during roll contact. Temperature changes due to material composition, reheating temperature, contact time and rolling conditions led to precipitation strengthening and roll chilling effects which have accounted for the excess load and torque observed experimentally and industrially.

Effects of Mg and Mn Contents on Hot-Rolling Temperature and Resultant Tensile Properties of Al-Mg-Mn Alloys

2016 ◽  
Vol 877 ◽  
pp. 334-339
Author(s):  
Bong Hwan Kim ◽  
Ji Y. Lee ◽  
Young Ok Yoon ◽  
Shae K. Kim
Keyword(s):  
Tensile Properties ◽  
Hot Rolling ◽  
Work Hardening ◽  
Rolling Temperature ◽  
Combined Effects ◽  
Surface Cracking ◽  
Rolling Experiment ◽  
Mn Content ◽  
Rolling Temperatures ◽  
Hot Rolled

The effects of Mg and Mn contents on hot-rolling temperature and resultant tensile properties of Al-Mg-Mn alloys were investigated. The Al-3.5Mg-0.3 alloy as a reference and Al-7.5Mg-0.3Mn, Al-3.5Mg-1.0Mn alloys were prepared by casting for hot-rolling experiment. The rolling temperatures of both Al-7.5Mg-0.3Mn and Al-3.5Mg-1.0Mn alloys had to be decreased due to surface cracking during hot-rolling, which is caused by increased fractions of Mg-containing phases like Mg2Al3. The tensile strength of the hot-rolled Al-7.5Mg-0.3Mn alloy was highly increased by the combined effects of enhanced solid-solution and work-hardening at lower rolling temperature. And the resultant tensile strengths of the hot-rolled Al-3.5Mg-1.0Mn alloy were also increased due to dispersoid hardening by increased Mn content and work hardening during hot-rolling.

scholarly journals Optimization Of Laboratory Hot Rolling Of Brittle Fe-40at.%Al-Zr-B Aluminide

2015 ◽  
Vol 60 (3) ◽  
pp. 1693-1702 ◽  
Author(s):  
I. Schindler ◽  
E. Hadasik ◽  
J. Kopeček ◽  
P. Kawulok ◽  
R. Fabík ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Rolling Process ◽  
Rolling Speed ◽  
Iron Aluminide ◽  
Strain Rates ◽  
Transverse Cracking ◽  
Hot Rolling Process ◽  
Mathematical Simulations ◽  
Effective Technology ◽  
Flat Rolling

Abstract Use of the protective steel capsules enabled to manage the laboratory hot flat rolling of the extremely brittle as-cast aluminide Fe-40at.%Al-Zr-B with the total height reduction of almost 70 %. The hot rolling parameters were optimized to obtain the best combination of deformation temperature (from 1160°C up to 1240°C) and rolling speed (from 0.14 m·s−1 to 0.53 m·s−1). The resistance against cracking and refinement of the highly heterogeneous cast microstructure were the main criteria. Both experiments and mathematical simulations based on FEM demonstrated that it is not possible to exploit enhanced plasticity of the investigated alloy at low strain rates in the hot rolling process. The heat flux from the sample to the working rolls is so intensive at low rolling speed that even the protective capsule does not prevent massive appearance of the surface transverse cracking. The homogeneity and size of product’s grain was influenced significantly by temperature of deformation, whereas the effect of rolling speed was relatively negligible. The optimal forming parameters were found as rolling temperature 1200°C and the rolling speed 0.35 m·s−1. The effective technology of the iron aluminide Fe-40at.% Al-Zr-B preparation by simple processes of melting, casting and hot rolling was thus established and optimized.

Microstructure, Texture and Mechanical Properties of Mg-2.0Zn-0.3Gd Alloy Sheets Fabricated by Large Strain Hot Rolling

2014 ◽  
Vol 788 ◽  
pp. 23-27 ◽  
Author(s):  
Jun Luo ◽  
Hong Yan ◽  
Rong Shi Chen ◽  
En Hou Han
Keyword(s):  
Mechanical Properties ◽  
Hot Rolling ◽  
Large Strain ◽  
Shear Bands ◽  
Rolling Process ◽  
Rolling Temperature ◽  
Obvious Effect ◽  
Peak Intensity ◽  
Hot Rolling Process ◽  
Rolling Temperatures

Mg-2Zn-0.3Gd sheets processed by large strain hot rolling with one pass of 80% reduction at 200°C and 250°C were selected to investigate the rolling temperature effect on the microstructure, texture and mechanical properties of Mg-2Zn-0.3Gd sheets after rolling and subsequent annealing. It was found that the rolling temperatures in the present study seemed to have no obvious effect on the microstructure of Mg-2Zn-0.3Gd sheets during large strain hot rolling process. High density of shear bands and numerous intersected twins but free of DRX grains were observed in the microstructure of both sheets. The Mg-2Zn-0.3Gd sheets showed non-basal textures with peaks tilting to TD after annealing. While the peak intensity of (0002) pole figure increased as the rolling temperature decreasing. Tensile testing results revealed that the Mg-2Zn-0.3Gd sheets rolled at both temperature displayed high room temperature ductility about 40% after annealing, which is due to the existence of non-basal texture.

Characterization of the texture evolution in AISI 430 and AISI 433 ferritic stainless steels during simulated hot rolling

MRS Advances ◽  
2018 ◽  
Vol 3 (34-35) ◽  
pp. 1985-2002
Author(s):  
K. A. Annan ◽  
C.W. Siyasiya ◽  
W.E. Stumpf
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Stainless Steels ◽  
Hot Rolling ◽  
Strain Rates ◽  
Mean Flow ◽  
Ferritic Stainless Steels ◽  
Fibre Texture ◽  
Rolling Temperatures ◽  
Aisi 430

AbstractMulti-pass compression tests were carried out on the Gleeble-1500D® and Gleeble-3800TM® thermo-mechanical simulators to investigate the effect of temperature, strain rate and inter-pass time on the development of the texture in ferritic stainless steels (FSS) AISI 430 and 433, the latter an Al-containing variant. Orientation Distribution Functions (ODFs) through the electron backscattered diffraction (EBSD) technique was employed to characterise and study the texture present in the steels after hot working. The mean flow stress analysis showed that, the dynamic recrystallization to dynamic recovery transition temperature decreases with an increase in strain rate in both grades of stainless steels possibly allowing texture optimisation at lower hot rolling temperatures. Higher finishing rolling temperatures, lower strain rates and longer inter-pass times led to improvement in the formation of the desired γ-fibre texture which contributes to ductility or drawability in these steels. Dynamic recrystallization which promotes the formation of the desired γ-fibre texture was found to occur in both AISI 430 and 433 at temperatures above 1000 °C and strain rates less than 5 s-1. Generally AISI 433 develops a stronger gamma texture than the AISI 430 when hot rolled under similar conditions.

Solid Solution Effects and Deformation Micros trueture of Shock-Loaded Iron Manganese Alloys

1970 ◽  
Vol 28 ◽  
pp. 420-421
Author(s):  
A. Christou ◽  
J. V. Foltz ◽  
N. Brown
Keyword(s):  
Solid Solution ◽  
Shock Loading ◽  
High Strain ◽  
Local Stress ◽  
Strain Rates ◽  
Local Stress Concentration ◽  
Bcc Metals ◽  
Manganese Alloys ◽  
Iron Manganese ◽  
Transmission Microscope

In general, all BCC transition metals have been observed to twin under appropriate conditions. At the present time various experimental reports of solid solution effects on BCC metals have been made. Indications are that solid solution effects are important in the formation of twins. The formation of twins in metals and alloys may be explained in terms of dislocation mechanisms. It has been suggested that twins are nucleated by the achievement of local stress-concentration of the order of 15 to 45 times the applied stress. Prietner and Leslie have found that twins in BCC metals are nucleated at intersections of (110) and (112) or (112) and (112) type of planes.In this paper, observations are reported of a transmission microscope study of the iron manganese series under conditions in which twins both were and were not formed. High strain rates produced by shock loading provided the appropriate deformation conditions. The workhardening mechanisms of one alloy (Fe - 7.37 wt% Mn) were studied in detail.

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