Modeling of steel hardening process at thermal and mechanical treatment

2019 ◽  
pp. 7-13
Author(s):  
A. S. Oryshchenko ◽  
V. A. Malyshevsky ◽  
E. A. Shumilov
Keyword(s):  
Mechanical Treatment ◽  
Thermomechanical Processing ◽  
High Strength Steels ◽  
High Strength ◽  
Accelerated Cooling ◽  
Rolling Mills ◽  
Hardening Process ◽  
Deformation Parameters ◽  
Research Complex ◽  
Steel Hardening

The article deals with modeling of thermomechanical processing of high-strength steels at the Gleeble 3800 research complex, simulating thermomechanical processing with various temperature and deformation parameters of rolling and with accelerated cooling to a predetermined temperature. The identity of steel hardening processes at the Gleeble 3800 complex and specialized rolling mills, as well as the possibility of obtaining steels of unified chemical composition, are shown.

Atomic Scale Investigation of Solutes and Precipitates in High Strength Steels

2013 ◽  
Vol 762 ◽  
pp. 14-21 ◽  
Author(s):  
Peter Hodgson ◽  
Subrata Mukherjee ◽  
Hossein Beladi ◽  
Xiang Yuan Xiong ◽  
Ilana B. Timokhina
Keyword(s):  
Retained Austenite ◽  
Thermomechanical Processing ◽  
Bainitic Ferrite ◽  
High Strength Steels ◽  
High Strength ◽  
Atom Probe ◽  
Atomic Scale ◽  
Isothermal Hold ◽  
Local Defects ◽  
Lower Carbon

Two steels, ferritic, high strength with interphase precipitation and nanobainitic, were used to show the advances in and application of atom probe. The coexistence of the nanoscale, interphase Nb-Mo-C clusters and stoichiometric MC nanoparticles was found in the high strength steel after thermomechanical processing. Moreover, the segregation of carbon at different heterogeneous sites such as grain boundary that reduces the solute element available for fine precipitation was observed. The APT study of the solutes redistribution between the retained austenite and bainitic ferrite in the nanobainitic steel revealed: (i) the presence of two types of the retained austenite with higher and lower carbon content and (ii) segregation of carbon at the local defects such as dislocations in the bainitic ferrite during the isothermal hold.

Development of High Strength Material and Pipe Production Technology for Grade X120 Line Pipe

2004 ◽  
Author(s):  
Hans-Georg Hillenbrand ◽  
Andreas Liessem ◽  
Karin Biermann ◽  
Carl Justus Heckmann ◽  
Volker Schwinn
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Point Of View ◽  
Accelerated Cooling ◽  
Pipe Production ◽  
Production Test ◽  
Low Carbon ◽  
Long Distance ◽  
Line Pipe ◽  
Economic Point

The increasing demand for natural gas will further influence the type of its transportation in the future, both from the strategic and economic point of view. Long-distance pipelines are a safe and economic means to transport the gas from production sites to end users. High-strength steels in grade X80 are nowadays state of the art. Grade X100 was recently developed but not yet utilised. The present-day technical limitations on the production of X120 line pipe namely the steel composition, the pipe forming and the welding are addressed in this paper. Production test results on X120 pipes are presented to describe the materials properties. A low carbon and low PCM steel with VNbTiB microalloying concept is used. In the plate rolling the main attention is turned to the heavy accelerated cooling. The large spring back that occurs during the U-forming step of the UOE process is one of the most complex aspects in forming X120. To handle this aspect FEM calculations were used to modify the forming parameters and to optimise the shape of the U-press tool. For optimising the existing welding procedure with respect to an avoidance of HAZ softening, a low heat input welding technology and new welding consumables were developed.

Effects of Thermomechanical Processing on Uniformity of Microstructure and Properties of AHSS

2014 ◽  
Vol 783-786 ◽  
pp. 967-972 ◽  
Author(s):  
Artem Marmulev ◽  
Lyudmila M. Kaputkina ◽  
Gwenola Herman ◽  
Evgueni I. Poliak
Keyword(s):  
Thermomechanical Processing ◽  
Dynamic Control ◽  
High Strength Steels ◽  
High Sensitivity ◽  
High Strength ◽  
Hot Strip Rolling ◽  
Controlled Cooling ◽  
Strip Rolling ◽  
Homogeneous Microstructure ◽  
Industrial Processing

Hot strip rolling of steels inherently results in non-homogeneous microstructure and mechanical properties of hot bands. Thermomechanical processing that implies careful selection of rolling temperatures, speeds, reductions and controlled cooling parameters, as well as their accurate in-bar dynamic control allows not only for reducing the inherent microstructure variability but also for attenuating and even eliminating the adverse downstream manifestations of microstructure non-homogeneities. This is especially pertinent to advance high strength steels (AHSS) for automotive applications that have been shown to possess high sensitivity to variations in industrial processing conditions. Examples of industrial data and real time monitoring of hot band microstructure evolution using online non-destructive technique are presented confirming the efficiency of thermomechanical processing in ensuring the proper quality of AHSS sheet products.

Improvement of strength and toughness: The effect on the weldability of high-strength steels used in offshore structures

2016 ◽  
Vol 231 (3) ◽  
pp. 369-376 ◽  
Author(s):  
Sammy-Armstrong Atta-Agyemang ◽  
Martin Appiah Kesse ◽  
Paul Kah ◽  
Jukka Martikainen
Keyword(s):  
Impact Toughness ◽  
High Strength Steels ◽  
High Strength ◽  
Offshore Structures ◽  
Controlled Rolling ◽  
Accelerated Cooling ◽  
Offshore Platforms ◽  
Zone Structure ◽  
Controlled Processing ◽  
Strength And Toughness

The effect of strength and toughness on the weldability of high-strength steels is very vital consideration in the offshore oil and gas industries. Improved impact toughness of high-strength steels in offshore structures enables viable exploitation of hydrocarbons in technologically challenging conditions. This article reviews improvements in the weldability and impact toughness of high-strength steels. Steels with high strength are associated with high carbon content and addition of alloying elements as they induce hardness which leads to a higher risk of brittle fracture and hydrogen-induced cracking needs. The combination of high strength with high toughness was studied by examining the toughening mechanism of thermomechanical-controlled processing steels, which have higher strength than conventional steel plates but meet the conflicting requirements of strength, toughness and weldability. The thermomechanical-controlled processing production process entails controlled rolling process combined with accelerated cooling or direct quenching to ensure stable mechanical properties of thermomechanical-controlled processing products in welded constructions. It is concluded that due to their very fine grain size and refined heat-affected zone structure, thermomechanical-controlled processing steels can be an effective cost-saving means for fabrication of offshore structures, particularly in shipbuilding, offshore platforms and pipelines for high-operating pressures.

scholarly journals The mechanical response of UFG and nanostructured microalloyed steels subjected to dynamic loading conditions

2018 ◽  
Vol 183 ◽  
pp. 03019
Author(s):  
Remigiusz Bloniarz ◽  
Janusz Majta ◽  
Carl P. Trujillo ◽  
Ellen K. Cerreta
Keyword(s):  
Mechanical Response ◽  
Split Hopkinson Pressure Bar ◽  
Thermomechanical Processing ◽  
High Strength Steels ◽  
High Strength ◽  
Microalloyed Steels ◽  
Large Strains ◽  
Loading Conditions ◽  
Hopkinson Pressure Bar ◽  
Pressure Bar

As the number of available, advanced high-strength metallic materials possibilities increases due to advancements in processing (for example advanced thermomechanical processing - ATP or severe plastic deformation - SPD), experimental comparisons alone are not sufficient for determination of the most ideal microstructures for specific applications. Our study deals with the dynamic behaviour of high strength steels and in particular with ultrafine-grained (UFG) microalloyed ferrite and austenite. The forming processes of modern UFG materials require rheological models describing the materials behaviour at large strains and strain rates up to over 1000 s-1. In our case, the mechanical response of UFG steels (produced using MaxStrain system) was investigated with split Hopkinson pressure bar (SHPB) tests, performed at room temperature. The dynamic work-hardening behaviour as a function of solute atoms and fine-scale, secondphase particles in the nano-structures of microalloyed ferrite and austenite has been compared to the mechanical response of these materials under quasi-static loading conditions.

Influence of Manufacturing Processes and Microstructures on the Performance and Manufacturability of Advanced High Strength Steels

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
K. S. Choi ◽  
W. N. Liu ◽  
X. Sun ◽  
M. A. Khaleel ◽  
J. R. Fekete
Keyword(s):  
Material Properties ◽  
Thermomechanical Processing ◽  
High Strength Steels ◽  
High Strength ◽  
Processing Parameters ◽  
Martensite Phase ◽  
Basic Material ◽  
Manufacturing Processes ◽  
Localized Deformation ◽  
Advanced High Strength Steels

Advanced high strength steels (AHSS) are performance-based steel grades and their global material properties can be achieved with various steel chemistries and manufacturing processes, leading to various microstructures. In this paper, we investigate the influence of the manufacturing process and the resulting microstructure difference on the overall mechanical properties, as well as the local formability behaviors of AHSS. For this purpose, we first examined the basic material properties and the transformation kinetics of three different commercial transformation induced plasticity (TRIP) 800 steels under different testing temperatures. The experimental results show that the mechanical and microstructural properties of the TRIP 800 steels significantly depend on the thermomechanical processing parameters employed in making these steels. Next, we examined the local formability of two commercial dual phase (DP) 980 steels which exhibit noticeably different formability during the stamping process. Microstructure-based finite element analyses are carried out to simulate the localized deformation process with the two DP 980 microstructures, and the results suggest that the possible reason for the difference in formability lies in the morphology of the hard martensite phase in the DP microstructure. The results of this study suggest that a set of updated material acceptance and screening criteria is needed to better quantify and ensure the manufacturability of AHSS.

scholarly journals Chemical heterogeneity enhances hydrogen resistance in high-strength steels

2021 ◽  
Author(s):  
Binhan Sun ◽  
Wenjun Lu ◽  
Baptiste Gault ◽  
Ran Ding ◽  
Surendra Kumar Makineni ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Thermomechanical Processing ◽  
High Strength Steels ◽  
High Strength ◽  
High Dispersion ◽  
Chemical Heterogeneity ◽  
Hydrogen Trapping ◽  
Strength And Ductility ◽  
Embrittlement Resistance ◽  
Hydrogen Embrittlement Resistance

AbstractThe antagonism between strength and resistance to hydrogen embrittlement in metallic materials is an intrinsic obstacle to the design of lightweight yet reliable structural components operated in hydrogen-containing environments. Economical and scalable microstructural solutions to this challenge must be found. Here, we introduce a counterintuitive strategy to exploit the typically undesired chemical heterogeneity within the material’s microstructure that enables local enhancement of crack resistance and local hydrogen trapping. We use this approach in a manganese-containing high-strength steel and produce a high dispersion of manganese-rich zones within the microstructure. These solute-rich buffer regions allow for local micro-tuning of the phase stability, arresting hydrogen-induced microcracks and thus interrupting the percolation of hydrogen-assisted damage. This results in a superior hydrogen embrittlement resistance (better by a factor of two) without sacrificing the material’s strength and ductility. The strategy of exploiting chemical heterogeneities, rather than avoiding them, broadens the horizon for microstructure engineering via advanced thermomechanical processing.

scholarly journals Effect of Cooling and Isothermal Holding on the Amount of Martensite/Austenite (M/A) Constituents, Microstructure and Mechanical Properties of Microalloyed Pipeline Steel

2018 ◽  
Vol 918 ◽  
pp. 152-158 ◽  
Author(s):  
Alexander Kabanov ◽  
Grzegorz Korpala ◽  
Rudolf Kawalla ◽  
Sergey Ionov
Keyword(s):  
Mechanical Properties ◽  
Pipeline Steel ◽  
Isothermal Holding ◽  
High Strength Steels ◽  
High Strength ◽  
Cold Climate ◽  
Throughput Capacity ◽  
Accelerated Cooling ◽  
Bainitic Steels ◽  
Strength And Plasticity

Constant increase of energy consumption in modern industry requires construction of heavily loaded pipelines with high throughput capacity. Therefore, high-strength steels should be used for the cost reasons. Additionally, the pipelines are also often used in the areas with cold climate and high seismicity. Therefore, strength and plasticity reduction is unacceptable. Bainitic steels with retained austenite (RA) or martensite/austenite (M/A) constituents meet these requirements. The purpose of this investigation is to determine thermo-mechanical treatment parameters with further accelerated cooling and additional isothermal holding for M/A-phase and mechanical properties formation. Experimental modeling of the production process was carried out using Gleeble HDS-V40 thermo-mechanical simulator. All investigations were realized with two high-strength micro-alloyed steels with different molybdenum and carbon content. Results showed that decrease of temperature and duration of isothermal holding as well as addition of molybdenum promote bainitic microstructure nucleation and reduce grain size and M/A-constituents. All these factors lead to a slight improvement in mechanical properties.

Optimising Thermomechanical Processing with Reduced Energy Demand

2012 ◽  
Vol 706-709 ◽  
pp. 2818-2823
Author(s):  
Tadeusz Siwecki ◽  
Johan Eliasson
Keyword(s):  
Hot Rolling ◽  
Energy Demand ◽  
High Strength Steels ◽  
High Strength ◽  
Parameters Optimization ◽  
Accelerated Cooling ◽  
Coiling Temperature ◽  
Steel Composition ◽  
Cooling Rates ◽  
Finish Rolling

Improving the steel properties and production processes with reduced energy demand for high strength steels requires improved process control in close relation to the steel composition. Hot rolling of steel is an energy-intensive process, especially in respect of preheating the steel slabs. The present work was carried out with the aim of reducing the initial slab temperature while at the same time improving properties by optimization of the steel composition and process parameters. Optimization of slab reheating and hot rolling parameters in connection with plate and strip rolling was carried out on low C-Mn high-strength steels microalloyed with Mo-Ti-Nb-B, both in laboratory and full scales processing. The effects of a low slab reheating temperature, high finish rolling temperature (FRT) during thermo-mechanical controlled processing (TMCP) and accelerated cooling rates following hot rolling to RT or to the coiling temperature have been investigated. Improvement of yield strength of the plate has been obtained by lowering the slab reheating temperature, especially with high cooling rates (>20°C/s) to room temperature. The results obtained for strip steels also show that a reduced reheating temperature combined with high finish rolling temperatures and cooling rates (>20°C/s) to a coiling temperature of 450°C produces very positive microstructures and mechanical properties in the present steels. Lowering the slab reheat temperature reduces energy consumption and accordingly releases less CO2 into the atmosphere during the thermo-mechanical processing of the present steels.

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