Effect of Thermomechanical Processing on Texture and Mechanical Properties of Al-Cu-Li Alloy Plate

2006 ◽  
Vol 519-521 ◽  
pp. 1585-1590 ◽  
Author(s):  
Alex Cho ◽  
Z. Long ◽  
B. Lisagor ◽  
T. Bales ◽  
Marcia S. Domack ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hot Rolling ◽  
Thermomechanical Processing ◽  
Surface Strength ◽  
Alloy Plate ◽  
Near Surface ◽  
Plate Design ◽  
Load Carrying ◽  
Surface Location ◽  
Rolling Practice

For 2195-T8 plate, design properties are based on the mechanical properties at the near surface location, corresponding to the load carrying thin membrane location in machined integrally stiffened structure. Mechanical properties at the near surface location are lower than those at the t/4 and t/2 locations. This work examined the effect of alternate temper and hot rolling practices on near surface strength levels. Results showed that alternate hot rolling practice were very effective in raising near surface strengths and improving property uniformity, and were well correlated with crystallographic texture measurements.

Optimization of Nb HSLA Microstructure Using Advanced Thermomechanical Processing in a CSP Plant

2007 ◽  
Vol 539-543 ◽  
pp. 28-35 ◽  
Author(s):  
Anthony J. DeArdo ◽  
R. Marraccini ◽  
Ming Jian Hua ◽  
C. Isaac Garcia
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Hot Rolling ◽  
Ultrasonic Testing ◽  
Thermomechanical Processing ◽  
Physical Metallurgy ◽  
Coiling Temperature ◽  
Hsla Steels ◽  
Final Microstructure ◽  
Rolling Practice

There are two obstacles to be overcome in the CSP production of HSLA heavy gauge strip and skelp, especially for API Pipe applications. First, the microalloying should be conserved by eliminating the high temperature precipitation of complex particles. Second, the heterogeneous microstructure that normally results from the 800 micron initial austenite in the 50mm slab as it is rolled to 12.5mm skelp must be eliminated to optimize the final microstructure and improve the final mechanical properties. Alteration in the hot rolling sequence can strongly homogenize the final austenite and resulting final ferritic microstructure. When coupled with a low coiling temperature near 550°C, the new rolling practice can result in Nb HSLA steels that can easily meet requirements for strength, toughness and ultrasonic testing in 12.5mm skelp gauges for X70 API pipe applications. The underlying physical metallurgy of these two breakthroughs will be presented and discussed in detail.

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.

Modelling of Oxide Scale Evolution in Hot Rolling and Descaling

2007 ◽  
Vol 539-543 ◽  
pp. 2461-2466 ◽  
Author(s):  
Michal Krzyzanowsky ◽  
John H. Beynon ◽  
Mike F. Frolish ◽  
Samantha Clowe
Keyword(s):  
Oxide Scale ◽  
Hot Rolling ◽  
Surface Deformation ◽  
Thermomechanical Processing ◽  
Near Surface ◽  
Modelling Techniques ◽  
The Subject ◽  
Hot Rolled ◽  
Roll Stock

Oxide scale behaviour in thermomechanical processing has been the subject of intensive research for several years that allowed developing a finite element (FE) based model to simulate a range of events of relevance to the process and the surface quality of the hot rolled product. A range of experimental techniques have also been developed, each providing a partial insight. An overview of this research is presented in the sequence of rolling and finishing with descaling. The model has been extended to provide the basis for detailed numerical investigations of the roll/stock interface behaviour during multi-pass hot rolling operations. The modelling techniques have been used for providing design criteria for AISI430 ferritic stainless steel scale failure during bending. Modelling of near surface deformation during rolling of aluminium alloys is under consideration.

Effects of Thermomechanical Processing on Microstructure and Mechanical Properties Multiphase Steels Exhibiting a TRIP Effect

2007 ◽  
Vol 539-543 ◽  
pp. 4357-4362 ◽  
Author(s):  
Jiří Kliber ◽  
Gabriela Plestilova ◽  
Ondrej Zacek ◽  
Mahesh C. Somani
Keyword(s):  
Mechanical Properties ◽  
Hot Rolling ◽  
Trip Steel ◽  
Transformation Temperature ◽  
Retained Austenite ◽  
Thermomechanical Processing ◽  
Rolling Temperature ◽  
Bainitic Transformation ◽  
Bainite Transformation ◽  
Microstructure And Mechanical Properties

Effects of hot-rolling conditions on these steels are much less studied than their importance for practice would suggest. It should be emphasized that bainite transformation is the key reaction to enrich non-transformed austenite with carbon. This study was carried out in order to gain understanding of the effect of thermomechanical hot rolling on final microstructure and mechanical properties of C-Mn-Si TRIP steel. Fundamental of the transformation induced plasticity effect – TRIP is the stabilization of substantial amount of retained austenite down to the ambient temperature by thermomechanical processing and its subsequent transformation into strain induced martensite as a consequence of applied plastic deformation. The special prepared stepped specimens were rolled on laboratory tandem mill. The effects of finish rolling temperature, strain and isothermal bainite transformation temperature on mechanical properties of mentioned TRIP steel were evaluated (mechanical properties were examined with tension test). Major deformation, higher finishing rolling temperature and higher temperature of bainite hold result in drop in strength. Proportionately to the drop in strength, the ductility grows in the TRIP steel. Microstructures were examined with X-ray diffraction (retained austenite). Image analysis software was used to process SEM micrographs of structure (ferrite, bainite assessment). Plastometric testing was conducted on GLEEBLE 3800 thermo-mechanical simulator. First stage of experiment yielded stress-strain curves for various temperatures and strain rates. Gleeble 1500 was used for the remaining plastometric simulation. Specimens were reheated to austenitization temperature of 1100°C and soaked. Then they were cooled to the temperature of deformation and subsequently cooled at higher rate down to the bainitic transformation temperature (400 – 550 °C). Specimens were held at the bainitic transformation temperature and then air-cooled. Final microstructures were evaluated with respect to transformation diagrams and optical microscopy findings. Higher bainite volume fraction was found in the specimens cooled at higher cooling rate as compared with more slowly cooled specimens.

Structural features and strength behavior of TRIP/TWIP steels

2020 ◽  
pp. 5-18
Author(s):  
D. V. Prosvirnin ◽  
◽  
M. S. Larionov ◽  
S. V. Pivovarchik ◽  
A. G. Kolmakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermomechanical Processing ◽  
Maximum Load ◽  
Structural Features ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Structural And Functional Properties ◽  
Twip Steels ◽  
The Creation

A review of the literature data on the structural features of TRIP / TWIP steels, their relationship with mechanical properties and the relationship of strength parameters under static and cyclic loading was carried out. It is shown that the level of mechanical properties of such steels is determined by the chemical composition and processing technology (thermal and thermomechanical processing, hot and cold pressure treatment), aimed at achieving a favorable phase composition. At the atomic level, the most important factor is stacking fault energy, the level of which will be decisive in the formation of austenite twins and / or the formation of strain martensite. By selecting the chemical composition, it is possible to set the stacking fault energy corresponding to the necessary mechanical characteristics. In the case of cyclic loads, an important role is played by the strain rate and the maximum load during testing. So at high loading rates and a load approaching the yield strength under tension, the intensity of the twinning processes and the formation of martensite increases. It is shown that one of the relevant ways to further increase of the structural and functional properties of TRIP and TWIP steels is the creation of composite materials on their basis. At present, surface modification and coating, especially by ion-vacuum methods, can be considered the most promising direction for the creation of such composites.

INFERRING THE COMPOSITION AND MECHANICAL PROPERTIES OF THE NEAR-SURFACE OF CERES FROM EMPLACEMENT MODELING OF LAYERED/PANCAKE-LIKE EJECTA DEPOSITS

2017 ◽  
Author(s):  
Kynan H.G. Hughson ◽  
◽  
Christopher T. Russell ◽  
Britney E. Schmidt ◽  
Heather Chilton ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Near Surface

scholarly journals 3D-FEM Simulation of Hot Rolling Process and Characterization of the Resultant Microstructure of a Light-Weight Mn Steel

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 569
Author(s):  
Ana Claudia González-Castillo ◽  
José de Jesús Cruz-Rivera ◽  
Mitsuo Osvaldo Ramos-Azpeitia ◽  
Pedro Garnica-González ◽  
Carlos Gamaliel Garay-Reyes ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Thermomechanical Processing ◽  
Computational Simulation ◽  
Effective Strain ◽  
Fem Simulation ◽  
Rolling Process ◽  
3D Fem ◽  
Hot Rolling Process ◽  
Mn Steel

Computational simulation has become more important in the design of thermomechanical processing since it allows the optimization of associated parameters such as temperature, stresses, strains and phase transformations. This work presents the results of the three-dimensional Finite Element Method (FEM) simulation of the hot rolling process of a medium Mn steel using DEFORM-3D software. Temperature and effective strain distribution in the surface and center of the sheet were analyzed for different rolling passes; also the change in damage factor was evaluated. According to the hot rolling simulation results, experimental hot rolling parameters were established in order to obtain the desired microstructure avoiding the presence of ferrite precipitation during the process. The microstructural characterization of the hot rolled steel was carried out using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the phases present in the steel after hot rolling are austenite and α′-martensite. Additionally, to understand the mechanical behavior, tensile tests were performed and concluded that this new steel can be catalogued in the third automotive generation.

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