Physical Simulation Methods Applied to Hot Rolling of Linepipe Steels

2018 ◽  
Vol 941 ◽  
pp. 438-442
Author(s):  
Fulvio Siciliano ◽  
Brian J. Allen ◽  
Samuel F. Rodrigues ◽  
John Joseph Jonas
Keyword(s):  
Hot Rolling ◽  
Physical Simulation ◽  
Simulation Analysis ◽  
Production Costs ◽  
Accelerated Cooling ◽  
Mean Flow ◽  
Mean Flow Stress ◽  
Steel Grades ◽  
Plant Equipment ◽  
Hot Torsion

The simulation of industrial rolling processes has been shown to be an important method to optimize rolling parameters, reduce production costs and improve product quality. Previous works have shown the value of hot rolling simulation by means of torsion tests where the mean-flow-stress (MFS) can be successfully predicted. In the present work, three rolling schedules are simulated by hot torsion tests and compared. It is important to note this methodology provides the flexibility to test different ideas without the risk of downtime or damage to plant equipment that could result from an unsuccessful industrial trial. The simulation analysis considered the production steps from reheating through the final accelerated cooling as well as the final product microstructures. The study provides important information to the production of various steel grades such as pipeline, shipbuilding, structural and other high-end products.

scholarly journals Physical Simulation Based on Dynamic Transformation Under Hot Plate Rolling of a Nb-Microalloyed Steel

2021 ◽  
Vol 8 ◽  
Author(s):  
João Carlos Ferreira ◽  
Francisco Romario de Sousa Machado ◽  
Clodualdo Aranas ◽  
Fulvio Siciliano ◽  
Jubert Pasco ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Physical Simulation ◽  
Accelerated Cooling ◽  
Mean Flow ◽  
Dynamic Transformation ◽  
Plate Rolling ◽  
Ferrite Fraction ◽  
Mean Flow Stress ◽  
Nb Microalloyed Steel ◽  
Rolling Load

In this work, the presence of dynamically formed ferrite above the Ae3 temperature during the physical simulation of hot rolling was presented. This unusual metallurgical process is known as dynamic transformation (DT). The metastable ferrite phase undergoes a reverse transformation when the temperature is held above the Ae3 by means of a diffusion process. These phenomena affect the rolling load during high-temperature plate rolling. Therefore, a linepipe X70 steel was studied under plate rolling with two-pass roughing and seven-pass finishing strains of 0.4 and 0.2, respectively, applied at strain rate of 1 s−1 and interpasses of 10, 20, and 30 s. The samples were cooling down during deformation, which mimics the actual industrial hot rolling. It was observed that the alloy softens as the hot rolling progresses, as depicted by flow curves and mean flow stress plots, which are linked to the combined effects of dynamic transformation and recrystallization. The former initially occurs at lower strains, followed by the latter at higher strains. The critical strain to DT was affected by the number of passes and temperature of deformation. Shorter interpass time allows higher amounts of ferrite to form due to higher retained work hardening. Similarly, the closer the deformation temperature to the Ae3 permits a higher DT ferrite fraction. The information from this work can be used to predict the formation of phases immediately after hot rolling and optimize models applied to the accelerated cooling.

scholarly journals Computer Model STAN 2000 and its Use in Practice of Steels Hot Rolling on Mill 2000 of Severstal

2016 ◽  
Vol 854 ◽  
pp. 183-189 ◽  
Author(s):  
Alexey Ogoltcov ◽  
Dmitry Sokolov ◽  
Semen Sokolov ◽  
Alexander Vasilyev
Keyword(s):  
Mechanical Properties ◽  
Computer Model ◽  
Hot Rolling ◽  
Relative Elongation ◽  
Integral Model ◽  
Accelerated Cooling ◽  
Chemical Compositions ◽  
Hot Strip ◽  
Steel Grades ◽  
Strip Production

An integral computer model/program STAN 2000 for simulation of steels hot rolling on mill 2000 of SEVERSTAL was developed. The capacity of the model includes, for example, the following features:‒ control of power parameters and prediction of hot strip temperature for a given rolling and accelerated cooling regimes;‒ follow-up of the evolution of steel microstructure at all stages of strip production and prediction of ultimate mechanical properties (yield stress, ultimate tensile stress and relative elongation);‒ optimization of rolling regimes for existing steel grades and developing them for a new ones.The STAN 2000 program is written in С++ programming language and can work on all modern Microsoft Windows family operating systems. The program has a well-designed and user-friendly interface facilitating its practical use.The integral model was calibrated using an extensive data base on rolling regimes and forces, measured temperatures and final mechanical properties for a number of steel grades rolled on mill 2000 of SEVERSTAL with chemical compositions covering the following ranges of alloying elements content (mass.%): С(≤0.65); Mn(≤2.0); Si(≤1.0); Cr(≤0.9); Ni(≤0.6); Cu(≤0.5); Mo(≤0.4); Nb(≤0.05); V(≤0.065); Ti(≤0.06); B(≤0.003).Some results of calculations performed with STAN 2000 program for temperatures, rolling forces and mechanical properties are presented and compared with experimental data. Some examples of the program utilization in hot strip production on mill 2000 of SEVERSTAL are presented and discussed.

Physical Simulation of Hot Rolling Steel Plate and Coil Production for Pipeline Applications

2013 ◽  
Vol 762 ◽  
pp. 70-75 ◽  
Author(s):  
Victor Carretero Olalla ◽  
N. Sanchez Mouriño ◽  
Philippe Thibaux ◽  
Leo Kestens ◽  
Roumen H. Petrov
Keyword(s):  
Mechanical Properties ◽  
Hot Rolling ◽  
Physical Simulation ◽  
Thermomechanical Processing ◽  
Charpy Impact ◽  
Processing Parameters ◽  
Accelerated Cooling ◽  
Air Cooling ◽  
Strong Impact ◽  
Structural Characterisation

Within the techniques and equipments used to simulate industrial thermomechanical processing of High Strength Low Alloy (HSLA) pipeline steels, hot rolling laboratory mill equipped with cooling bed and coiling simulation furnace allows, not only accurate control of strains, temperatures, inter-pass times, and cooling rates but also enough amount of processed material for micro-structural characterisation and mechanical testing. Despite some differences with the industrial rolling, laboratory rolling offers a better simulation of the industrial rolling conditions than other thermo-mechanical simulators in terms of deformation mechanisms and processing constrains. This paper presents the results of simulation of different rolling schedules applied on pipeline grades in order to better understand the influence of the finishing rolling parameters namely: finish rolling temperature (FRT) and cooling routes on the microstructure and mechanical properties. It was observed that FRT and cooling rate have a strong impact on both grain refinement and precipitation behaviour, which leads to significant differences in strength and toughness. Furthermore variations of the above mentioned rolling parameters produce distinct fractions and distributions of austenite transformation products, variations in the final crystallographic texture and trigger diverse strengthening mechanisms (i.e. dislocation hardening). It was found that the accelerated cooling in a combination with a coiling simulation results in formation of microstructures with well developed low angle grain boundaries in comparison to the simulation made with air cooling. As a consequence the strength of the plates after accelerated cooling increases without changes in the Charpy impact toughness. It has been shown that the understanding of the effect of processing parameters on the microstructure of these steels is a key aspect for the optimization of their mechanical properties.

Determination of the Non-Recrystallisation Temperature (Tnr) of Austenite in High Strength C-Mn Steels

2012 ◽  
Vol 706-709 ◽  
pp. 2722-2727 ◽  
Author(s):  
Jai Gautam ◽  
Alexis G. Miroux ◽  
J. Moerman ◽  
Carla Barbatti ◽  
Peter van Liempt ◽  
...  
Keyword(s):  
Flow Stress ◽  
Work Hardening ◽  
High Strength ◽  
Mean Flow ◽  
Alternative Approach ◽  
Interpass Time ◽  
Work Hardening Rate ◽  
Mean Flow Stress ◽  
Hot Torsion

In the present study non-recrystallisation (Tnr) and Ar3 temperatures have been determined for the C-Mn steels from multi-pass hot torsion experiments with continuous cooling in the temperature range of 1260°C to 600°C. Results show that Tnr decreases with increasing strain/pass, strain rate or interpass time. An alternative approach based on the work-hardening rate is proposed for the determination of Tnr and is shown to be more suitable in case the usual mean flow stress method does not provide a clear Tnr value.

Practical Use of Computer Model STAN 2000 for Improvement and Creation of Regimes for Hot Rolling of Steels on SEVERSTAL Mill 2000

2016 ◽  
Vol 879 ◽  
pp. 2543-2548 ◽  
Author(s):  
Alexey Ogoltcov ◽  
Dmitry Sokolov ◽  
Semen Sokolov ◽  
Alexander Vasilyev
Keyword(s):  
Mechanical Properties ◽  
Computer Model ◽  
Hot Rolling ◽  
Relative Elongation ◽  
Ultimate Tensile Stress ◽  
Integral Model ◽  
Accelerated Cooling ◽  
Chemical Compositions ◽  
Steel Grades ◽  
Strip Production

An integral computer model STAN 2000 designed for of-line simulation and control of hot rolling on mill 2000 of SEVERSTAL was developed. The capabilities of the model include the following features: ‒ calculations of power parameters for all stands of mill 2000 for a given rolling schedule; ‒ strip temperature calculations depending on selected rolling and accelerated cooling regimes; ‒ follow-up of steel microstructure evolution at all stages of strip production and prediction of ultimate mechanical properties (yield stress, ultimate tensile stress, relative elongation and toughness); ‒ optimization of rolling regimes for existing steel grades and developing them for a new one. The STAN 2000 program is written in С++ programming language and can work on all modern Microsoft Windows family operating systems. The program has a well-designed and user-friendly interface facilitating its practical use. The integral model was calibrated using an extensive data base on rolling regimes and forces, measured temperatures and final mechanical properties for a number of steel grades rolled on mill 2000 of SEVERSTAL with chemical compositions covering the following range of alloying elements content (mass.%): С(≤0.65); Mn(≤2.0); Si(≤1.0); Cr(≤0.9); Ni(≤0.6); Cu(≤0.5); Mo(≤0.4); Nb(≤0.05); V(≤0.065); Ti(≤0.06); B(≤0.003). The examples of STAN 2000 program use in practice of industrial hot strip production on mill 2000 of SEVERSTAL are presented and discussed.

Microstructure Evolution Characterization of Multi-Pass Hot Rolling Simulation of Nb-Ti Microalloyed Steel

2014 ◽  
Vol 936 ◽  
pp. 1141-1145
Author(s):  
Bin Shen ◽  
Song He Zhu ◽  
Heng Hua Zhang
Keyword(s):  
Hot Rolling ◽  
Static Recrystallization ◽  
Microalloyed Steel ◽  
Measured Data ◽  
Mean Flow ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Mean Flow Stress ◽  
The Mean

In this study, a improved mathematical model was developed for Nb-Ti microalloyed steel during hot rolling simulation. Using the compression test, the dynamic and static recrystallization characteristics of Nb-Ti microalloyed steel were studied. Though multi-pass hot rolling simulation, it is found that the recrystallization during hot rolling can play an important role, it can make the mean flow stress lower and refine the grains. And respective comparison between calculated and measured data of microstructure showed some of the validation of the built model. Meanwhile, the evolution characteristic of average austenite grain size during hot rolling can be achieved by theoretical model and experiment.

Hot Torsion Tests - A Reliable Rolling Simulation Method for C-Mn Steels

2016 ◽  
Vol 879 ◽  
pp. 1783-1787 ◽  
Author(s):  
Fulvio Siciliano ◽  
Brian Allen ◽  
David Ferguson
Keyword(s):  
Flow Stress ◽  
Hot Deformation ◽  
Simulation Method ◽  
Absolute Temperature ◽  
Mean Flow ◽  
Torsion Testing ◽  
Torsion Mode ◽  
Mean Flow Stress ◽  
The Mean ◽  
Hot Torsion

Torsion tests have been proven to be a successful method to simulate the hot rolling of steels. Simulation work performed at a laboratory scale together with the analysis of the resulting mean-flow-stress behavior, leads to important metallurgical information to be considered during full-scale rolling processes. In this work, two different hot deformation schedules of C-Mn steels have been performed on a Gleeble simulation system in hot torsion mode. In addition to the torsion tests, the mean-flow-stresses of industrial rolling data were analyzed. Industrial hot deformation schedules simulated using hot torsion and the mean-flow-stress values were plotted versus the inverse of absolute temperature in the same graph. All points match the same behavior showing that torsion testing is a reliable hot working simulation method.

New Phenomenological Model of Hot Mean Flow Stress

2013 ◽  
Vol 32 (2) ◽  
pp. 133-138
Author(s):  
Ivo Schindler ◽  
Petr Kawulok ◽  
Stanislav Rusz ◽  
Jiří Plura ◽  
Zdeňek Vašek ◽  
...  
Keyword(s):  
Flow Stress ◽  
Hot Rolling ◽  
Effective Strain ◽  
Single Equation ◽  
Mean Flow ◽  
Strain And Strain Rate ◽  
Wide Range ◽  
Mean Flow Stress ◽  
Experimental Values ◽  
Fast Prediction

AbstractBased on the measurement of roll forces during the laboratory hot rolling of flat samples graded in thickness, the new phenomenological type of mean flow stress model was developed and applied on plain-carbon and HSLA steels. The obtained models describe with a very good accuracy the hot deformation resistance characteristics in the temperature range 1123 to 1463 K, large effective strain, and strain rate in the useful range of approximately 10 to 100 s−1. Difficulty in the mathematical description of the influence of temperature on mean flow stress in the wide range of temperature by a single equation was solved by introducing another constant in the temperature member of the conventional model. The newly proposed model solves by phenomenological means a frequent problem of heteroscedasticity of relative deviations between the calculated and experimental values of mean flow stress values depending on temperature. It becomes more reliable from the viewpoint of the operational application, e.g. fast prediction of mean flow stress values and power/force parameters necessary in the steering systems of hot rolling mills.

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