scholarly journals TECHNOLOGY OF HEAT TREATMENT OF THE LARGE SECTION BARS MADE OF STRUCTURAL STEEL USING CONTROLLED CONTINUOUS COOLING FROM THE AUSTENITE PHASE

2020 ◽  
Vol 72 (1) ◽  
pp. 2-20
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Structural Steel ◽  
Hot Rolling ◽  
Accelerated Cooling ◽  
Controlled Cooling ◽  
Treatment Technology ◽  
Heating And Cooling ◽  
Air Stream ◽  
The Impact

The article presents the results of studies on the impact of accelerated cooling after the austenitisation of bars with a diameter of 180 mm made of structural steel S355J2 on the microstructure and mechanical properties. The aim of the research was to develop basic parameters of heat treatment technology using the heat remaining in the bars after hot rolling. Tests of heating and cooling of the bars were carried out in devices included in the line for semi-industrial hot rolling simulation, controlled cooling and heat treatment (LPS-B) at Łukasiewicz – IMŻ. The following cooling operations were performed after bar austenitisation: cooling in still air, controlled cooling with air blow, water-air mixture, water spraying and immersion cooling in water. Based on the research and analyses, it was found that the use of optimised variants of accelerated cooling leads to the modification of the microstructure and to grain refinement, without the formation of undesirable phase components. Consequently, the mechanical properties (yield strength and impact toughness) increase above the level obtained as a result of cooling in still air, including standard normalisation. Preliminary tests of accelerated air stream cooling of bars were carried out after austenitising in industrial conditions. The final criterion for selecting and implementing the type of technology for heat treatment of bars using heat after hot rolling in Huta Bankowa’s technical and technological conditions will be the assessment of the economic efficiency of the project.

Influence of Mn and Heat Treatment Technology on Microstructure and Mechanical Properties of a Low-Alloy Wear-Resistant Cast Steel Shovel Tooth

2012 ◽  
Vol 557-559 ◽  
pp. 34-37
Author(s):  
Jing Qiang Zhang ◽  
Jie Min Du ◽  
Ji Wei Guo ◽  
Shou Fan Rong ◽  
Guang Zhou Wang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Toughness ◽  
Cast Steel ◽  
Treatment Technology ◽  
Wear Resistant ◽  
Heat Treatment Technology ◽  
Microstructure And Mechanical Properties ◽  
Mn Content ◽  
The Impact

The influences of Mn and heat-treatment technology on microstructure and mechanical properties of medium-carbon-low-alloy wear-resistant cast steel were investigated. The results show that the hardness first increases and then drops down with the increase of Mn content, and the best hardness is 54HRC with Mn content 1.5%. The impact toughness first increases and then drops down with the increase of Mn content. The hardness and impact toughness first increase and then drop down with the increases of quenching temperature. The optimal impact toughness can be obtaind by quenching at 920°C and tempering at 200°C. Part of lower bainite and residual austenite and mass of tempered martensite are obtaind after tempering.

scholarly journals Investigation of the influence of heat treatment modes of experimental steels for new generation railway rails on mechanical properties

2020 ◽  
pp. 247-255
Author(s):  
A.I. Babachenko ◽  
R.V. Podolskyi ◽  
G.A. Kononenko ◽  
Е.А. Safronova
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Operational Reliability ◽  
Operating Conditions ◽  
Railway Track ◽  
Controlled Cooling ◽  
Furnace Heating ◽  
Heating And Cooling ◽  
Cooling Media

The safety of railway transport depends on the quality of the metal, the efficiency of the technology for manufacturing rails and wheelsets, and the operating conditions of the railway track. The operational durability of rails is largely determined by the structural state and mechanical properties of the metal of the rail elements. On the basis of a comparative analysis of various methods and modes of treatment of railway rails, it was found that one of the ways to increase the operational reliability of rails can be the optimization of methods for heating and cooling the metal when implementing the modes of their heat treatment. A study of the microstructure of steel laboratory melts up to 10 kg, melted under the conditions of the IHM NASU (the symbol of which is PCT), after furnace heating with cooling the blanks for tensile specimens (55x12x12mm) in various cooling media: in calm air, under a ventilator, blowing with compressor air in water with a temperature of 80˚С. It is found that at cooling rate 5,1˚С / s (cooling air compressor) is obtained a homogeneous structure of fine pearlite with a hardness of the metal at the level of foreign standards. On the basis of technical sources, it has been established that volumetric furnace heating followed by immersion of the test specimens made of steel with 0,84%С, 0,44% Si, 0,95% Mn into an environment providing the metal with a controlled cooling rate of ≈5.1˚C / s contributes to the formation of a lamellar pearlite structure with a hardness of 415 HB. It was found that the use of furnace heating leads to the production of homogeneous austenite in the volume of the samples under study.

INFLUENCE THE QUENCHING AND TEMPERING ON THE MICROSTRUCTURE, MECHANICAL PROPERTIES AND SURFACE ROUGHNESS, OF MEDIUM CARBON STEEL

2018 ◽  
Vol 18 (1) ◽  
pp. 125-135
Author(s):  
Sattar H A Alfatlawi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Surface Roughness ◽  
Carbon Steel ◽  
Cold Water ◽  
Medium Carbon Steel ◽  
Medium Carbon ◽  
Heating And Cooling ◽  
Treatment Processes ◽  
Quenching And Tempering

One of ways to improve properties of materials without changing the product shape toobtain the desired engineering applications is heating and cooling under effect of controlledsequence of heat treatment. The main aim of this study was to investigate the effect ofheating and cooling on the surface roughness, microstructure and some selected propertiessuch as the hardness and impact strength of Medium Carbon Steel which treated at differenttypes of heat treatment processes. Heat treatment achieved in this work was respectively,heating, quenching and tempering. The specimens were heated to 850°C and left for 45minutes inside the furnace as a holding time at that temperature, then quenching process wasperformed in four types of quenching media (still air, cold water (2°C), oil and polymersolution), respectively. Thereafter, the samples were tempered at 200°C, 400°C, and 600°Cwith one hour as a soaking time for each temperature, then were all cooled by still air. Whenthe heat treatment process was completed, the surface roughness, hardness, impact strengthand microstructure tests were performed. The results showed a change and clearimprovement of surface roughness, mechanical properties and microstructure afterquenching was achieved, as well as the change that took place due to the increasingtoughness and ductility by reducing of brittleness of samples.

scholarly journals Damage Evolution of Granodiorite after Heating and Cooling Treatments

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 779
Author(s):  
Mohamed Gomah ◽  
Guichen Li ◽  
Salah Bader ◽  
Mohamed Elkarmoty ◽  
Mohamed Ismael
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Failure Mode ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Physical Parameters ◽  
Slow Cooling ◽  
Heating And Cooling ◽  
Natural Rock ◽  
The Impact

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.

The Effect of Aging Heat Treatment on the Microstructure and Mechanical Properties of 10Cr20Ni25Mo1.5NbN Austenitic Steel

2016 ◽  
Vol 35 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Zhiyuan Liang ◽  
Wanhua Sha ◽  
Qinxin Zhao ◽  
Chongbin Wang ◽  
Jianyong Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Austenitic Steel ◽  
Treatment Time ◽  
Aging Treatment ◽  
Secondary Phases ◽  
Aging Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
The Impact

AbstractThe effect of aging heat treatment on the microstructure and mechanical properties of 10Cr20Ni25Mo1.5NbN austenitic steel was investigated in this article. The microstructure was characterized by scanning electron microscopy, energy dispersive spectrometry and transmission electron microscopy. Results show that the microstructure of 10Cr20Ni25Mo1.5NbN austenitic is composed of austenite. This steel was strengthened by precipitates of secondary phases that were mainly M23C6 carbides and NbCrN nitrides. As aging treatment time increased, the tensile strength first rose (0–3,000 h) and then fell (3,000–5,000 h) due to the decrease of high density of dislocations. The impact absorbed energy decreased sharply, causing the sulfides to precipitate at the grain boundary. Therefore, the content of sulfur should be strictly controlled in the steelmaking process.

Application of Tailored Heat Treated Blanks under Quasi Series Conditions

2007 ◽  
Vol 344 ◽  
pp. 383-390 ◽  
Author(s):  
Marion Merklein ◽  
Uwe Vogt
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Local Heat ◽  
Strength Distribution ◽  
Process Window ◽  
Short Term ◽  
Forming Process ◽  
Heat Treated ◽  
Set Up ◽  
The Impact

Tailored Heat Treated Blanks (THTB) are blanks that exhibit locally different strength specifically optimized for the succeeding forming process. The strength distribution is set by a local, short-term heat treatment modifying the mechanical properties of the material. Hence, THTB allow enhancing forming limits significantly leading to shorter and more robust manufacture process chains. In order to qualify the use of THTB under quasi series conditions, the interdependencies of the blank’s local heat treatment and the entire process chain of the car body manufacture have to be analyzed. In this respect, the impact of a short-term heat treatment on the mechanical properties of AA6181PX, a commonly used aluminum alloy in today’s car bodies, was studied. Also the influence of a short-term heat treatment on the coil lubricant, usually already applied by the material supplier, was given a closer look. Based on these experiments process restrictions for the application of THTB in an industrial automotive environment were derived and a process window for the THTB design was set up. In conclusion, strategies were defined how to enhance the found process boundaries leading to a more robust process window.

scholarly journals Heat Treatment of Steel 1.1730 with Concentrated Solar Energy

2019 ◽  
Vol 56 (1) ◽  
pp. 261-270
Author(s):  
Maria Stoicanescu ◽  
Aurel Crisan ◽  
Ioan Milosan ◽  
Mihai Alin Pop ◽  
Jose Rodriguez Garcia ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Solar Radiation ◽  
Solar Energy ◽  
Vertical Axis ◽  
Solar Furnace ◽  
Solid Base ◽  
Heating And Cooling ◽  
Concentrated Solar Energy ◽  
Wide Range ◽  
The Impact

This paper presents and discusses research conducted with the purpose of developing the use of solar energy in the heat treatment of steels. For this, a vertical axis solar furnace called at Plataforma Solar de Almeria was adapted such as to allow control of the heating and cooling processes of samples made from 1.1730 steel. Thus temperature variation in pre-set points of the heated samples could be monitored in correlation with the working parameters: the level of solar radiation and implicitly the energy used the conditions of sample exposed to solar radiation, and the various protections and cooling mediums.The recorded data allowed establishing the types of treatments applied for certain working conditions. The distribution of hardness, as the representative feature resulting from heat treatment, was analysed on all sides of the treated samples. In correlation with the time-temperature-transformation diagram of 1.1730 steel, the measured values confirmed the possibility of using solar energy in all types of heat treatment applied to this steel. In parallel the efficiency of using solar energy was analysed in comparison to the energy obtained by burning methane gas for the heat treatment for the same set of samples. The analysis considered energy consumption, productivity and the impact on the environment. Thanks to various data obtained through developed experiences, which cover a wide range of thermic treatments applied steels 1.1730 model, we can certainly state that this can be a solid base in using solar energy in applications of thermic treatment at a high industrial level.

Effect of Hot-Rolling Parameters on Microstructure and Mechanical Properties of 72LXA Steel Wire Rod

2012 ◽  
Vol 581-582 ◽  
pp. 842-846
Author(s):  
Jian Hua Zeng ◽  
Yi Chang Li ◽  
Zheng Zhou ◽  
Jun Chen
Keyword(s):  
Mechanical Properties ◽  
Hot Rolling ◽  
Steel Wire ◽  
Rolling Process ◽  
Impact Factors ◽  
Cooling Process ◽  
Controlled Cooling ◽  
Wire Rod ◽  
Microstructure And Mechanical Properties ◽  
Proeutectoid Ferrite

Effect of the laying head temperature and controlled cooling process on microstructure and mechanical properties of 72LXA wire rod were investigated．The results show that under the same cooling process，with the raising laying temperature and increasing sorbitizing rate and decreasing proeutectoid ferrite，the steel rod strength is improving，proeutectoid ferrite and sorbitizing rate are the critical impact factors on steel rod properties；indentifying cooling after perlite forming can restrain the dissolve of lamellar cementite；the mechanical properties of whole rod coil are improved by the proper rolling rate and air cooling．The high strength of 1050 MPa of steel rod was obtained，that shows the defined hot rolling process can conform to the steel rod properties requirement．

Numerical Simulation of the H-Beam during Cooling Process

2013 ◽  
Vol 310 ◽  
pp. 145-149 ◽  
Author(s):  
Jian Liu ◽  
Fu Zeng Hou ◽  
Xiao Guang Yu
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Heat Treatment ◽  
Theoretical Basis ◽  
Treatment Process ◽  
Residual Austenite ◽  
Heat Treatment Process ◽  
Cooling Process ◽  
Controlled Cooling ◽  
H Beam

In order to improve the comprehensive mechanical properties of the steel, the heat treatment software COSMAP is used to simulate the rolling and controlled cooling of H-beam. The numerical simulation shows that the mechanical properties of controlled cooling can be obviously improved, when the cooling rate is controlled at 10°C/s around. Strength and hardness can be improved under the condition of ductility and toughness ensured. Meanwhile the amount of residual austenite can be reduced significantly. It provides a theoretical basis for further optimization of the heat treatment process.

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