scholarly journals Modeling of the Steel Microstructure Gained after the Application of an Ultra-Fast Heat Treatment

2017 ◽  
Vol 2 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Marianthi Bouzouni
Keyword(s):  
Heat Treatment ◽  
Steel Microstructure

Effects of Heat Treatment on Microstructure Parameters, Mechanical Properties and Cold Resistance of Sparingly Alloyed High-Strength Steel

2021 ◽  
Vol 410 ◽  
pp. 197-202
Author(s):  
Pavel P. Poleckov ◽  
Olga A. Nikitenko ◽  
Alla S. Kuznetsova
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cold Resistance ◽  
Heating Temperature ◽  
High Strength ◽  
Steel Microstructure ◽  
Treatment Conditions ◽  
Microstructure Parameters ◽  
Temperature Impact ◽  
Low Temperature Impact Toughness

This study considers the influence of various heat treatment conditions on the change of steel microstructure parameters, mechanical properties and cold resistance at a temperature of-60 °C. The common behavior of these properties is considered depending on the heating temperature used for quenching and subsequent tempering. Based on the obtained results, heat treatment conditions are proposed that provide a combination of a guaranteed yield point σ0.2 ≥600 N/mm2 with a low-temperature impact toughness KCV-60 ≥50 J/cm2 and plasticity δ5 ≥17%. The obtained research results are intended for industrial use at the mill "5000" site of MMK PJSC.

scholarly journals The Microstructure and Phase Composition of 35CrSiMN5-5-4 Steel After Quenching and Partitioning Heat Treatment

2016 ◽  
Vol 61 (3) ◽  
pp. 1683-1688
Author(s):  
E. Skołek ◽  
K. Wasiak ◽  
W.A. Świątnicki
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Retained Austenite ◽  
Lower Bainite ◽  
Treatment Technology ◽  
Quenching And Partitioning ◽  
Steel Microstructure ◽  
Transmission Electron ◽  
Dilatometric Studies ◽  
Good Agreement

Abstract The aim of the study was to characterise the microstructure of 35CrSiMn5-5-4 steel which was subjected to a new heat treatment technology of quenching and partitioning (Q&P). The parameters of the treatment were chosen on the basis of computer simulations and dilatometric studies of phase transformations occurring in steel. The transmission electron microscopy (TEM) observations of steel microstructure after the Q&P treatment revealed the presence of martensite as well as significant amount of retained austenite in form of layers between the martensite laths. The rod-like carbides in the ferritic areas were also observed, which indicates the presence of lower bainite in steel. It was found that the retained austenite content measured by means of TEM was about 28% for partitioning at 400°C and 25% for partitioning at 260°C. These results are in good agreement with the phase composition calculated theoretically as well as those determined experimentally by use of dilatometric tests.

The Physical and Numerical Modelling of Heat Treatment of Experimental Steels for Pipelines

2015 ◽  
Vol 220-221 ◽  
pp. 754-759
Author(s):  
Bartosz Koczurkiewicz ◽  
Marcin Knapiński ◽  
Henryk Dyja ◽  
Anna Kawałek
Keyword(s):  
Heat Treatment ◽  
Numerical Modelling ◽  
Physical Simulation ◽  
Characteristic Temperature ◽  
Metallographic Examination ◽  
Steel Microstructure ◽  
Continuous Cooling ◽  
University Of Technology ◽  
Commercial Program ◽  
Numerical Research

The paper presents the results of the physical and numerical modelling of heat treatment of experimental steels for pipelines. Simulation has been conducted at the Institute of Metal Forming and Safety Engineering of Częstochowa University of Technology. The numerical modelling of heat treatment has been carried using commercial program TTSteel. Based on the results of computer simulation, changes in steel microstructure during continuous cooling have been analysed, and the characteristics of temperature and the diagram of Continuous Cooling Transformation (CCT) have been constructed. Numerical research has been verified running the physical simulation of heat treatment of steel using dilatometer DIL805 A/D. The characteristic temperature of steel and the size of the former austenite grains have been determined. Also, the metallographic examination of the samples was conducted and Vickers hardness was tested. The obtained results have been used for building a real CCT diagram of steel.

The Physical and Numerical Modeling of Heat Treatment the Experimental Complex-Phase (CP) Steel

2012 ◽  
Vol 706-709 ◽  
pp. 1497-1502 ◽  
Author(s):  
J. Rapalska ◽  
Henryk Dyja ◽  
Bartosz Koczurkiewicz
Keyword(s):  
Heat Treatment ◽  
Numerical Modeling ◽  
Automotive Industry ◽  
Physical Simulation ◽  
Characteristic Temperature ◽  
Complex Phase ◽  
Plastic Properties ◽  
Metallographic Examination ◽  
Steel Microstructure ◽  
Experimental Complex

The fast development of automotive industry effects significantly on aspirations of designers and constructors to reduces the mass-produced cars, affecting meaningly on fuel consumption and gas emition. From the standpoint of automotive industry materials for modern car-body sheets should have high mechanical properties (primarily high tensil strenght) and very good cupping. The required high mechanical and plastic properties steels used in produce of car bodies are dependent on the type of the obtaining structure, witch be shaped by an appropriate heat and thermo-plastic treatment. The modern steels used in automotive industry are multi-phase steels e.g. dual-phase (DP), complex-phase (CP) and transformation induced plasticity (TRIP) steels. In this paper are presented the results of physical and numerical modeling of heat treatment the experimental complex-phase steel, witch be conducted in the Institute of Modeling and Automation of Plastic Working Processing on Częstochowa University of Technology. The numerical modellig of heat treatment were carried with using the commercial programe TTSteel. Based on the results of computer simulation the changes of steel microstructure during continuous cooling were analyzed and the characteristics temperature and CCT diagram was constructed. Numerical research have been verified by the physical simulation of heat treatment by the dilatometer DIL805. The characteristic temperature of investigated steel and the size of initial austenite grains were determined. On the samples was also metallographic examination and Vickers hardness testing conducted. The obtained results were used to build a real CCT diagram of steel.

scholarly journals Evolution of non-metallic inclusions during heat treatment

2020 ◽  
Vol 117 (4) ◽  
pp. 408
Author(s):  
Chengsong Liu ◽  
Bryan Webler
Keyword(s):  
Heat Treatment ◽  
Size Distribution ◽  
Inclusion Size ◽  
Isothermal Heat Treatment ◽  
Number Density ◽  
Inclusion Composition ◽  
Steel Microstructure ◽  
Metallic Inclusions ◽  
Higher Temperature ◽  
Average Size

Isothermal heat treatment can not only modify steel microstructure, but also non-metallic inclusions. In this work, heat treatment experiments were conducted between 1373 and 1573 K (1100 and 1300 °C) to study the evolution of inclusion composition, morphology, and size distribution. Results showed that during the heat treatment at 1473 and 1573 K (1200 and 1300 °C), two main kinds of inclusions initially in the steel, CaS and MgO–Al2O3–CaO–CaS, gradually transformed to (Ca, Mn)S and MgO–Al2O3–(Ca, Mn)S inclusions, and some MgO–Al2O3–CaO inclusions also transformed to MgO–Al2O3–(Ca, Mn)S. At the lowest temperature studied, 1373 K (1100 °C), little change was observed. No significant changes in number density and area fraction of the measured inclusions were observed, while the average size of inclusions increased after the heat treatment. The extent of transformation of CaS, MgO–Al2O3–CaO–CaS and MgO–Al2O3–CaO inclusions increased with decreasing inclusion size and higher temperature.

scholarly journals Influence of Steel Structure on Machinability by Abrasive Water Jet

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4424 ◽  
Author(s):  
Irena M. Hlaváčová ◽  
Marek Sadílek ◽  
Petra Váňová ◽  
Štefan Szumilo ◽  
Martin Tyč
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Mechanical Characteristics ◽  
Water Jet ◽  
Abrasive Waterjet ◽  
Abrasive Water Jet ◽  
Roughness Parameters ◽  
Steel Microstructure ◽  
Surface Roughness Parameters ◽  
Awj Cutting

Although the abrasive waterjet (AWJ) has been widely used for steel cutting for decades and there are hundreds of research papers or even books dealing with this technology, relatively little is known about the relation between the steel microstructure and the AWJ cutting efficiency. The steel microstructure can be significantly affected by heat treatment. Three different steel grades, carbon steel C45, micro-alloyed steel 37MnSi5 and low-alloy steel 30CrV9, were subjected to four different types of heat treatment: normalization annealing, soft annealing, quenching and quenching followed by tempering. Then, they were cut by an abrasive water jet, while identical cutting parameters were applied. The relations between the mechanical characteristics of heat-treated steels and the surface roughness parameters Ra, Rz and RSm were studied. A comparison of changes in the surface roughness parameters and Young modulus variation led to the conclusion that the modulus was not significantly responsible for the surface roughness. The changes of RSm did not prove any correlation to either the mechanical characteristics or the visible microstructure dimensions. The homogeneity of the steel microstructure appeared to be the most important factor for the cutting quality; the higher the difference in the hardness of the structural components in the inhomogeneous microstructure was, the higher were the roughness values. A more complex measurement and critical evaluation of the declination angle measurement compared to the surface roughness measurement are planned in future research.

scholarly journals Determining the Optimum Conditions for Heat Treatment of Cold Rolling Mill Rolls by Studying Their Influence on the Microstructure and Properties of the Billet

2019 ◽  
pp. 449-459
Author(s):  
Polina A. Krapivina ◽  
Michael A. Gervasyev
Keyword(s):  
Heat Treatment ◽  
Cold Rolling ◽  
Rolling Mill ◽  
Original Structure ◽  
Process Conditions ◽  
Optimum Conditions ◽  
Cold Rolling Mill ◽  
Steel Microstructure ◽  
Carbide Network ◽  
Treatment Conditions

Quality, reliability, and service durability of mill rolls are critical factors determining the quality of finished products and efficiency of rolling mills. The main problem that arises in the course of production of steel forged mill rolls is selection of reasonable conditions of heat treatment. As far as the size of the grain with an original structure and the pattern of distribution of separate structural components within the billet play a significant role in formation of final properties of the article, the objectives of this work are studying the heat treatment influence on the microstructure and hardness of steel mill rolls and development of reasonable process conditions on the basis of obtained data, in particular: determining the optimum conditions of primary heat treating the cold rolling mill rolls after their forging to reach the homogeneous structure and reduce the carbide grid score and carbide liquation; determining the optimum conditions of secondary thermal treatment of cold rolling mill rolls to provide the hardness within the range of about 300 HB, favorable structure for industrial frequency current hardening and reduction of carbide network score and carbide liquation; determining the hardening temperature, holding time and cooling rate to obtain the optimum structure and hardness within the range of 650-700 HB. Optimization of heat treatment conditions and analysis of steel microstructure have been performed with the application of cylindrical items (diameter 30 mm, height 20 mm) cut from the sample and template. Based on the study findings some microscopic images of steel microstructure after application of certain heat treatment conditions have been made and data on carbide network and current grain evaluation have been obtained

Integral Computer Model for Simulating Microstructure Evolution during Thermomechanical Processing and Heat Treatment of Steels and Predicting their Final Mechanical Properties

2021 ◽  
Vol 1016 ◽  
pp. 1532-1537
Author(s):  
Alexander Alexandrovich Vasilyev ◽  
Dmitry Sokolov ◽  
Semen Sokolov ◽  
N.G. Kolbasnikov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Computer Model ◽  
Thermomechanical Processing ◽  
Quantitative Description ◽  
Experimental Studies ◽  
Steel Structure ◽  
Chemical Compositions ◽  
Steel Microstructure ◽  
Physically Based

An integral computer model/program AusEvol Pro was developed to describe the evolution of steel microstructure during thermomechanical processing (hot rolling, forging), as well as subsequent heat treatment (normalization, tempering), and to evaluate the final mechanical properties (yield stress, tensile stress, elongation), hardness and impact toughness. The program implements a set of physically based models that allow quantitative description of all significant processes of steel structure formation with account of the effects of chemical composition both during thermomechanical processing and heat treatment. Calculations of the final mechanical properties are carried out using the developed models that take into account all physically meaningful contributions. The models created are verified both on the extensive database of our own experimental studies and on reliable data from literature for steels of various chemical compositions.

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