scholarly journals Investigation of the effect of isothermal heat treatments on mechanical properties of thermo-mechanically rolled S700MC steel grade

2020 ◽  
Vol 26 (1) ◽  
pp. 11-16
Author(s):  
Serkan Oktay ◽  
Paolo Emilio Di Nunzio ◽  
Mustafa Kelami Şeşen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Energy ◽  
Heat Treatments ◽  
Steel Grade ◽  
Secondary Hardening ◽  
Precipitation Kinetics ◽  
High Supersaturation ◽  
Bainitic Structure ◽  
Isothermal Heat Treatments

The effect of isothermal heat treatments (1 hour at 200, 400, 600 and 800°C) on mechanical properties of thermo-mechanically rolled S700MC steel has been investigated by extensive mechanical characterizations. Treatments at 600°C increase yield and tensile strength and decrease impact energy. Below 600°C the steel retains its bainitic structure. Precipitation kinetics simulations indicate that this secondary hardening effect arises from the nucleation of fine (Nb,Ti)C particles, indicating that the bainitic structure is unstable above 600°C due to its high supersaturation with respect to C, Nb and Ti. These results can help to optimize the operating practices for post-weld heat treatments.

Effects of electrode type on the mechanical properties of weldments of some steel samples produced in Nigeria

2014 ◽  
Vol 11 (2) ◽  
pp. 95-106 ◽  
Author(s):  
Bayo Okediran ◽  
Danjuma Yawas ◽  
Ibraheem Samotu ◽  
I. Dagwa ◽  
David Obada
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Energy ◽  
Chemical Compositions

The effects of electrode types on the mechanical properties of weldments produced from three steel samples made locally in Nigeria have been investigated. Oerlikon, Santan, Power Master and Magnum electrode samples were separately used to join Homus, Universal and Spanish steel samples. The chemical compositions of the steel samples, electrodes core and coating were obtained using spectrometer before using them for the research. Mechanical properties of the weldment produced were determined and compared to the unwelded samples. This was done in order to provide information on which combination of steel and electrode type will produce weldment with optimum mechanical properties. Oerlikon electrode produces weldments with optimum tensile strength of 508.25 N/mm2 and impact energy of 152.76J for Homus Steel, it also produced highest tensile strength of 449.92 N/mm2 and impact energy of 103.042J for Spanish Steels while Power Master Electrode produced weldment with highest tensile strength of 482.96N/mm2 and impact energy of 137.033J for Universal Steel. The results show that single electrode type cannot produce weldment with highest properties for all the selected steel samples.

scholarly journals Preparation and Mechanical Properties of ZK61-Y Magnesium Alloy Wheel Hub via Liquid Forging—Isothermal Forging Process

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 385
Author(s):  
Yushi Qi ◽  
Heng Wang ◽  
Lili Chen ◽  
Hongming Zhang ◽  
Gang Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Heat Treatments ◽  
Second Phase ◽  
Phase Hardening ◽  
Isothermal Forging ◽  
Forging Process ◽  
Microstructure And Mechanical Properties ◽  
Alloy Wheel

A ZK61-Y magnesium (Mg) alloy wheel hub was prepared via liquid forging—isothermal forging process. The effects of Y-element contents on the microstructure and mechanical properties of liquid forging blanks were investigated. The formation order of the second phase was I-phase (Mg3Zn6Y) → W-phase (Mg3Zn3Y2) → Z-phase (Mg12ZnY) with the increase of the Y-element content. Meanwhile, the I-phase and Z-phase formed in the liquid forging process were beneficial to the grain refinement. The numerical simulation of the isothermal forging process was carried out to analyze the effects of forming temperature on the temperature and stress field in the forming parts using the software Deform-3D. Isothermal forging experiments and post heat treatments were conducted. The influence of isothermal forging temperature, heat treatment temperature and preservation time on the microstructure and mechanical properties of the forming parts were also studied. The dynamic recrystallization (DRX), second-phase hardening, and work hardening account for the improvement of properties after the isothermal forging process. The forming part forged at 380 °C displayed the outstanding properties. The elongation, yield strength, and ultimate tensile strength were 18.5%, 150 MPa and 315 MPa, respectively. The samples displayed an increased elongation and decreased strength after heat treatments. The 520 °C—1 h sample possessed the best mechanical properties, the elongation was 25.5%, the yield stress was 125 MPa and the ultimate tensile strength was 282 MPa. This can be ascribed to the recrystallization and the elimination of working hardening. Meanwhile, the second phase transformation (I-phase → W-phase → Mg2Y + MgZn2), dissolution, and decomposition can be observed, as well.

The Influence of Austenisation Temperature and Holding Time on Mechanical Properties, Scale Thickness, and Microstructure in Alloy Steel

2015 ◽  
Vol 776 ◽  
pp. 239-245
Author(s):  
Abdul Aziz ◽  
Maulud Hidayat ◽  
Indah Hardiyanti
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Alloy Steel ◽  
Impact Energy ◽  
Holding Time ◽  
Micro Structure ◽  
Scale Thickness ◽  
Alloy Steels ◽  
Steel Weight

The application of steel products have been widely used and various research have been developed to find a good and appropriate quality of steel and can be produced in the country without have to be imported, for example alloy steels. One of the alloy steels that have been constantly developed is Ni-Cr-Mo alloy steel with additional nickel, chromium and molybdenum which can increase hardness, tensile strength, ductility and toughness. The effect during the production process is at the heating process that causes the formation of iron oxide layer (scale) and the loss of steel weight. Therefore, the selection of heat treatment methods and techniques are required to increase the mechanical properties of steel, such as hardness, tensile strength, and toughness, with the scale is about <5% of steel weight. In this research, the heat treatment was carried out at austenisation temperature of 800°, 850°, 900°C and at holding time of 20, 40, 60 minutes, then followed by a rapid cooling (quenching) to improve the mechanical properties of hardness. This research also tested the mechanical properties of steel that consist of hardness test and impact test, and metallographic observation that consist of micro structure observation and scale thickness observation. The micro structure from heat treatment process is martensite, it is due to a rapid cooling (quenching) that rapidly change the austenite phase into martensite. The data showed the highest hardness is 588.35 HVN at 850°C of temperature and 60 minutes of holding time, 8.5 Joules of impact energy, and 91.5 μm of scale thickness. While the lowest hardness is 539.34 HVN at 800°C of temperature, 5 Joules of impact energy, and 47.81 μm of scale thickness.

Investigation of Heat Treatment on Mechanical Properties of SAE4320 and SAE8620 Alloys

2013 ◽  
Vol 834-836 ◽  
pp. 816-819 ◽  
Author(s):  
Li Jun Tan ◽  
Jun Qiao Wang ◽  
Qing Qun Wang ◽  
Xin Long Chen ◽  
Si Zhu Zhou
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Impact Toughness ◽  
Deformation Property ◽  
New Product ◽  
Heat Treatments ◽  
Impact Properties ◽  
The Impact

The tensile and impact properties of SAE4320 and SAE8620 alloys were investigated. Various heat treatments were applied to these two alloys, including different pre-heat treatment. The results shown that after Carburizing and Quenching, both SAE4320 and SAE8620 alloys were highly sensitively to V-notches for their impact samples. In any case, SAE4320 alloy revealed higher tensile strength, better impact toughness and deformation property. Previous work shown that after Carburizing and Quenching, the impact toughness of SAE8620 alloy was too low, the products made of it was very dangerous. Based on the results, a new advanced product was made of SAE4320 alloy instead of SAE8620 alloy. And the new product exhibited good properties. The impact value of the new product far exceeded the older products.

Experimental Research and Analysis of Non-alloy Structural Steel Response Exposed to High Temperature Conditions

2013 ◽  
Vol 32 (2) ◽  
pp. 163-169
Author(s):  
Josip Brnic ◽  
Goran Turkalj ◽  
Sanjin Krscanski
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Structural Steel ◽  
Impact Energy ◽  
Charpy Impact ◽  
Experimental Results ◽  
Charpy Impact Energy ◽  
Over Time

AbstractThis paper presents and analyzes the responses of non-alloy structural steel (1.0044) subjected to uniaxial stresses at high temperatures. This research has two important determinants. The first one is determination of stress-strain dependence and the second is monitoring the behavior of materials subjected to a constant stress at constant temperature over time. Experimental results refer to mechanical properties, elastic modulus, total elongations, creep resistance and Charpy V-notch impact energy. Experimental results show that the tensile strength and yield strength of the considered material fall when the temperature rises over 523 K. Significant decrease in value is especially noticeable when the temperature rises over 723 K. In addition, engineering assessment of fracture toughness was made on the basis of Charpy impact energy. It is visible that when temperature raises then impact energy increases very slightly.

Effect of Heat Treatments on Microstructure and Mechanical Properties of Low Carbon Steel Pipes Welded by Induction Process

2014 ◽  
Vol 887-888 ◽  
pp. 1301-1306
Author(s):  
Zakaria Boumerzoug ◽  
Lakhdar Lakhdari
Keyword(s):  
Mechanical Properties ◽  
Isothermal Annealing ◽  
Pipeline Steel ◽  
Low Carbon Steel ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Low Carbon ◽  
Steel Pipes ◽  
Induction Process ◽  
Isothermal Heat Treatments

In this work, the effect of isothermal heat treatments on microstructure evolution and mechanical properties after welding by induction of A37 pipeline steel have been studied by scanning electron microscopy, hardness measurements, and tensile tests. Microstructural evolution in welded joint was identified after isothermal annealing from 200 until 900 °C.

The Effect of the Normalizing Rolling of S355J2G3 Steel Round Bars on the Selected Mechanical Properties of Finished Product

2010 ◽  
Vol 165 ◽  
pp. 294-299 ◽  
Author(s):  
Konrad Błażej Laber ◽  
Henryk Dyja
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Stress ◽  
Rolling Mill ◽  
Research Work ◽  
Testing Machine ◽  
Rolling Process ◽  
Constructional Steel ◽  
Steel Grade ◽  
Bar Rolling

The paper presents investigation results related to the effect of application of round plain bar normalizing rolling on the selected mechanical properties of finished product. The research was carried out for the process of rolling 38 mm-diameter plain round bars made of constructional steel S355J2G3, based on actual specifications used in industrial conditions in a continuous bar rolling mill. In the course of investigation the yield stress, YS, and the tensile strength, TS, were determined. With the aim of evaluating the effect of controlled (normalizing) rolling on the mechanical properties of the considered steel grade, Zwick Z/100 testing machine was employed and analytical relationships were used. On the basis of performed research work it was established that enhancement of mechanical properties of the considered steel can be obtained as a result of application of the normalizing rolling process.

scholarly journals Effects of Austempering on the Microstructure, Corrosion and Mechanical Properties of AISI 1018 Steel

2021 ◽  
Author(s):  
Oluwole Daniel Adigun ◽  
Muyideen Adebayo Bodude ◽  
Aanuoluwapo Rebecca Adigun ◽  
Babatunde Abiodun Obadele ◽  
Abdullahi Olawale Adebayo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Energy ◽  
Room Temperature ◽  
Low Carbon Steel ◽  
Salt Bath ◽  
Isothermal Transformation ◽  
Low Carbon ◽  
Micro Hardness ◽  
Microstructural Investigation

Abstract In this study, the effects of austempering on the microstructure, mechanical properties (micro hardness, impact energy and tensile strength) and corrosion behaviours of AISI 1018 low carbon steel were evaluated. The steel specimens were subjected to heat treatment by austenitizing at 830°C, maintained in this condition for 90 min before rapid cooling in a NaNO3 salt bath sustained at 300°C for isothermal transformation for additional 50 min and finally allowed to air cool to room temperature. The as-received and the austempered samples were tested for corrosion in both 0.5M aqueous acidic (HCl) and 0. 5M alkaline (NaOH) media. Microstructural investigation using scanning electron microscope (SEM) reveals transformation from ferrite/pearlite phases to bainite over the austempering process. Interestingly, significant improvements of 15.7% to 95.7% in the various mechanical properties (micro hardness, impact energy and tensile strength) and corrosion resistance in both media were observed.

scholarly journals Grain Refinement and Improved Mechanical Properties of EUROFER97 by Thermo-Mechanical Treatments

2021 ◽  
Vol 11 (22) ◽  
pp. 10598
Author(s):  
Giulia Stornelli ◽  
Andrea Di Schino ◽  
Silvia Mancini ◽  
Roberto Montanari ◽  
Claudio Testani ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Heat Treatments ◽  
Treatment Temperature ◽  
Steel Plates ◽  
Experimental Campaign ◽  
Different Temperatures ◽  
Fusion Applications ◽  
Cold Rolled

EUROFER97 steel plates for nuclear fusion applications are usually manufactured by hot rolling and subsequent heat treatments: (1) austenitization at 980 °C for 30 min, (2) rapid cooling and (3) tempering at 760 °C for 90 min. An extended experimental campaign was carried out with the scope of improving the strength of the steel without a loss of ductility. Forty groups of samples were prepared by combining cold rolling with five cold reduction ratios (20, 40, 50, 60 and 80%) and heat treatments at eight different temperatures in the range 400–750 °C (steps of 50 °C). This work reports preliminary results regarding the microstructure and mechanical properties of all the cold-rolled samples and the effects of heat treatments on the samples deformed with the greater CR ratio (80%). The strength of deformed samples decreased as heat treatment temperature increased and the change was more pronounced in the samples cold-rolled with greater CR ratios. After heat treatments at temperature up to 600 °C yield stress (YS) and ultimate tensile strength (UTS) of samples deformed with CR ratio of 80% were significantly larger than those of standard EUROFER97 but ductility was lower. On the contrary, the treatment at 650 °C produced a fully recrystallized structure with sub-micrometric grains which guarantees higher strength and comparable ductility. The work demonstrated that EUROFER97 steel can be strengthened without compromising its ductility; the most effective process parameters will be identified by completing the analyses on all the prepared samples.

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