Research on the Optimization of Heat Treatment Process and the Abrasive Impact Wear Mechanism of 70Mn Steel

2013 ◽  
Vol 395-396 ◽  
pp. 308-312
Author(s):  
Peng Deng ◽  
Ren Bo Song ◽  
Ting Sun ◽  
Xu Wang
Keyword(s):  
Heat Treatment ◽  
Wear Mechanism ◽  
Treatment Process ◽  
Orthogonal Experiment ◽  
Optical Microscope ◽  
Experimental Results ◽  
Experimental Result ◽  
Heat Treatment Process ◽  
Impact Wear ◽  
Optimum Heat

This research was conducted on the influence of heat treatment parameters on the mechanical properties and abrasive wear resistance of 70Mn steel through experimental results. Orthogonal experiment was applied for designing heat treatment process and acquired optimal heat treatment parameters. The experimental results showed that the optimum heat treatment process was firstly heated to 830°C preserved for 60min, and rapidly quenched, then tempered at 200°C for 80min. Abrasive impact wear experiment was performed on MLD-10 tester, under which the wear surface and the subsurface were observed through scanning electron microscope and optical microscope. According to the experimental result, abrasive impact wear mechanism was analyzed. The results showed that plastic deformation fatigue and gouging wear were the primary mechanisms of abrasive impact wear, together with a small amount of furrow and cutting.

Machine Design for Multiscale Nitinol Annealment Process and End Product Performance Analysis

2020 ◽  
Author(s):  
Amanda Skalitzky ◽  
Stuart Coats ◽  
Ramsis Farag ◽  
Austin Gurley ◽  
David Beale
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Heat Treating ◽  
Experimental Results ◽  
Heat Treatment Process ◽  
Scanning Calorimetry ◽  
Niti Wire ◽  
Annealing Temperatures ◽  
Conventional Heat Treatment ◽  
Post Production

Abstract The functional properties of Nitinol (NiTi) are set by composition, production process, and post-production heat treatment and cold working. Post-production heat treating is dependent on two main parameters: anneal temperature and aging time. Most heat-treating processes performed by researchers generally consist of simple temperature soaks at specified aging times. However, there are drawbacks to this method. More complex heat treatments can result in performance improvements, but they are difficult to implement and often proprietary to manufacturers and therefore not widely used by researchers. By designing a Continuously-Fed heat treatment System (CFS), this work demystifies this complex heat-treatment process by rapidly heat-treating NiTi wire samples across a range of annealing temperatures, soak times, and tensions with little human intervention. This automated process ensures samples are created in a consistent manner and results in a much more consistent end-product when compared to conventional heat-treating methods. Using the CFS, a gamut of samples with varying annealing temperatures (400–550°C) and aging times (1–3 minutes) were created with 0.25mm diameter high-temperature actuator wire initially in the ‘as-drawn’ condition. Differential Scanning Calorimetry (DSC) analysis was performed to determine how the transition temperature(s) change with the various heat-treating parameters and the mechanical properties of the wire were determined utilizing a tensile test. The experimental results demonstrate the benefits of the CFS and are compared to those of a more conventional heat treatment process. Experimental results show that high-performance Nitinol actuator behavior can consistently be achieved using the CFS. Optimal heat treatment processes can be determined quickly experimentally.

Failure Analysis and Study on Heat Treatment Process of Grate Bars Used in Sintering Trolley

2014 ◽  
Vol 1061-1062 ◽  
pp. 454-459
Author(s):  
An Min Li ◽  
Ding Ma ◽  
Qi Feng Zheng ◽  
Ruo Huai Chen ◽  
Qiang Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Residual Austenite ◽  
Shrinkage Porosity ◽  
Heat Treatment Process ◽  
Fracture Characteristics ◽  
Heat Treated ◽  
Primary Means ◽  
Optimum Heat ◽  
Optimum Heat Treatment

The as-cast grate bar structure used in sintering trolley is primarily comprised of austenite and eutectic (eutectic austenite and eutectic carbide).The austenite is dendrite, while the carbides are reticular and chrysanthemum-like. The failed grate bar structure primarily consists of ferrite, carbide, martensite and residual austenite; cavity shrinkage and shrinkage porosity exist in the structure, and the fracture exhibits typical cleavage fracture characteristics. The primary means of failure are abrasion and fracture. The secondary carbides precipitated in the sample (quenching (1050°C+2.5h)+ tempering (390°C+2.5h)) and the other one (quenching (1050°C+2.5h)+ tempering (420°C+2.5h) ) are dispersed and refined. Compared with the as-cast one, their relative abrasion resistance performances respectively are 0.8645 and 0.8752.The values of hardness and impact toughness of the samples heat-treated are greater than those of the as-cast grate bar. The optimum heat treatment process is as follows: quenching (1050°C,2.5h) + tempering (390°C~420°C,2.5h)

scholarly journals Effect of Heat Treatments on Microstructural Evolution and Tensile Properties of 15Cr12MoVWN Ferritic/Martensitic Steel

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1271
Author(s):  
Tingwei Ma ◽  
Xianchao Hao ◽  
Ping Wang
Keyword(s):  
Heat Treatment ◽  
Tensile Properties ◽  
Room Temperature ◽  
Treatment Process ◽  
Martensitic Steel ◽  
Heat Treatment Process ◽  
Lath Width ◽  
Optimum Heat ◽  
Martensitic Lath ◽  
Optimum Heat Treatment

In this study, the phase transformation temperature of 15Cr12MoVWN ferritic/martensitic steel was determined by differential scanning calorimetry to provide a theoretical basis for the design of a heat treatment process. An orthogonal design experiment was performed to investigate the relationship between microstructure and heat treatment parameters, i.e., normalizing temperature, cooling method and tempering temperature by evaluating the room-temperature and elevated-temperature tensile properties, and the optimum heat treatment parameters were determined. It is shown that the optimized heat treatment process was composed of normalizing at 1050 °C followed by air cooling to room temperature and tempering at 700 °C. Under the optimum heat treatment condition, the room-temperature tensile properties were 1014 MPa (UTS), 810.5 MPa (YS) and 18.8% (elongation), while the values are 577.5 MPa (UTS), 469 MPa (YS) and 39.8% (elongation) tested at 550 °C. The microstructural examination shows that the strengthening contributions from microstructural factors were the martensitic lath width, dislocations, M23C6, MX and grain boundaries of prior austenite grain (PAG) in a descending order. The main factors influencing the tensile strength of 15Cr12MoVWN steel were the martensitic lath width and dislocations.

scholarly journals Hardness and Conductivity of Die Forged ZYK530 Magnesium Alloy

2021 ◽  
Author(s):  
Fenghong CAO ◽  
Yaohui XU ◽  
Chang CHEN ◽  
Zhaohui QIN ◽  
Chi DENG
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Treatment Process ◽  
Mg Alloy ◽  
Heat Treatment Process ◽  
Optimum Heat ◽  
The Relationship ◽  
Optimum Heat Treatment ◽  
Good Agreement ◽  
Peak Value

The relationship among the microstructure, hardness and electrical conductivity of the as-forged ZYK530 Mg alloy after heat treatment was analyzed and studied using a microscope, X-Ray Diffractometer, eddy current conductivity meter, and Vickers microhardness tester, to explore optimum heat treatment process of ZYK530 Mg alloy. The results show that: with the prolongation of holding time, the electrical conductivity and microhardness show the same change trend, both of which show an oscillatory upward trend, and then decrease in an oscillatory downward trend after reaching the  peak value. There is a linear positive correlation between the conductivity and the hardness, and the fitting results of the conductivity and hardness are in good agreement with the measured results; combined with the actual production, when the heat-treatment is 480 ℃ × 8 h + 220 ℃ × 3 h, the highest hardness is 79.2 HV, the electroconductivity is 36.2%IACS, and the comprehensive performance is the best, which is the best heat treatment process.

Influence of Heat Treatment on the Microstructure and Properties of 7Cr17Mo Martensitic Stainless Steel

2013 ◽  
Vol 820 ◽  
pp. 15-19
Author(s):  
Xiao Dong Du ◽  
Zi Li Song ◽  
Yi Qing Chen ◽  
Jia Qing Wang ◽  
Guang Fu Liu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Retained Austenite ◽  
Treatment Process ◽  
Martensitic Stainless Steel ◽  
Optical Microscope ◽  
Heat Treatment Process ◽  
Quenching Temperature ◽  
Microstructure And Properties ◽  
The Impact

This paper describes the influence of heat treatment process on the microstructure and properties of a new martensitic stainless steel, which contains 0.7% carbon, 17% chromium and 1% molybdenum and can be used as kitchen knives and scissors. The microstructure and properties of the tested alloys after quenching at 980 - 1100 °C and low tempering were investigated by means of optical microscope (OM), scanning electron microscope (SEM), Rockwell hardness tester and impact tester. The results show that the microstructure consists of acicular martensite, carbides and a litter retained austenite after quenching and tempering. The carbides are mainly (Fe,Cr)23C6. The content of retained austenite increases with the increase of the quenching temperature. The solubility of carbon in martensite changes similarly. The martensite gets coarser as the quenching temperature increasing. The maximum value of hardness is 59 HRC, when the quenching temperature is 1060 °C. The impact toughness increases when the quenching temperature increases from 980 °C to 1080 °C and then decreases. The suitable heat treatment process for this alloy is quenching at 1060 °C~1080 °C for 30 min and then tempering at 200°C.

scholarly journals PENGARUH MEDIA QUENCHING TERHADAP KEKERASAN DAN STRUKTUR MIKRO PASKA HARDFACING

2018 ◽  
Vol 3 (2) ◽  
pp. 66-72
Author(s):  
Basori Basori
Keyword(s):  
Heat Treatment ◽  
Carbon Steel ◽  
Treatment Process ◽  
Low Carbon Steel ◽  
Optical Microscope ◽  
Heat Treatment Process ◽  
Low Carbon ◽  
Water Media

AbstrakHardfacing dengan proses SMAW merupakan salah satu teknik yang paling banyak digunakan, karena sangat mudah diaplikasikan seperti pada scoops lift buckets , Ripper Teeth, dan Dozer Blades.. Hardfacing pada komponen ini bertujuan untuk mencegah keausanan yang diakibatkan benturan atau gesekan saat penggalian tanah, pengumpulan tanah, pengangkutan tanah pada saat alat berat sedang bekerja. Setelah baja karbon rendah di hardfacing, kemudian dilakukan perlakuan panas dengan Quenching dengan tujuan lebih meningkatkan kekerasan dari material. Pembuatan spesimen dilakukan dengan teknik SMAW polaritas AC arus 100A menggunakan elektroda HV 450 kemudian spesimen di potong, di lakukan proses heat treatment. Setelah selesai kemudian speseimen di uji keras dan dilakukan pengamatan dengan mikroskop optik. Media air merupakan media yang paling optimal dalam menigkatkan kekerasan dari hasil hardfacing. Nilai kekerasan yang didapatkan dari hasil quenching dengan media air adalah sebesar 422.66 VHNKata kunci: Hardfacing, SMAW, Struktur Mikro dan Kekerasan AbstractHardfacing with the SMAW process is one of the most common techniques, because it is very easy to apply as in lift buckets Scoops, Ripper Teeth, and Dozer Blades. Hardfacing in this component for the situation caused by collisions or friction during excavation of land, transporting the soil when the machine is working. After low carbon steel hardfacing, then heat is done with quenching in order to increase the hardness of the material. The making of specimens was carried out using the SMAW technique using HV 450 electrodes and then the specimens were cut, and the heat treatment process was carried out. After completion, the experiment was carried out and an observation with an optical microscope was carried out. Water media is the most optimal media in increasing the hardness of hardfacing results. The value obtained from the quenching with water media is 422.66 VHN Keywords: Hardfacing, SMAW, Microstructure and Hardness

scholarly journals Study of Mechanical Properties and Microstructure of Mercedes-Benz and Local Radiator Material

2020 ◽  
Vol 24 (3) ◽  
pp. 185
Author(s):  
Usman Sudjadi ◽  
Rahmad Jayadiningrat ◽  
Erwan Hermawan ◽  
Agus Jamaludin
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Chemical Composition ◽  
Grain Boundaries ◽  
Treatment Process ◽  
Optical Microscope ◽  
Heat Treatment Process ◽  
Test Results ◽  
Binding Material ◽  
The Matrix

            Indonesia has the capability to produced local products such as vehicle radiators. Many studied were carried out to characterize the radiator material. But it still needs to compare local products and imported products. This study carried mechanical properties and microstructure analysis for Marcedes Benz's core radiator and local radiator. The tools used in this study are microhardness tools, optical microscopes, and XRF. The result shows that the Mercedes-Benz radiator binding material before the heat treatment process, using an optical microscope shows the invisible results of a collection of atoms and the matrix and grain boundaries. On local radiator material, Not yet seen the collection of atoms and matrix and grain boundaries. White grains of Mercedes Benz radiator material is more abundant than local radiator materials. Chemical composition test results are; local radiator material content is dominated by three elements Ca (26.3%), Zn (44.4%) and Cu (13.9%) Cu (2.48%), Fe (45.15%), and Mn (44.88%). The German Mercedes-Benz element contents are; Fe (28.7), Mn (27.5), Ca (39.2). The hardness of the Mercedes-Benz radiator before heating is 43.4 HV, after being heated 39.2 HV. The hardness local radiator material before heating 43.5 HV and after heating 38.2 HV.

Influence of Molybdenum Replacement by Tungsten in Cr Mo V Steel

2020 ◽  
Vol 835 ◽  
pp. 50-57
Author(s):  
Saeed Ghali ◽  
Mohamed Kamal El-Fawkhry ◽  
Taha Mattar
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Induction Furnace ◽  
Optical Microscope ◽  
Intermetallic Phases ◽  
Air Cooling ◽  
Heat Treatment Process ◽  
Total Replacement ◽  
Steel Grades ◽  
Precipitated Phases

This article aims at investigation the effect of partial and total replacement of molybdenum by tungsten in ordinary heat resistance steel, in term of constituent phases. Three steel grades of P91 steel were produced in induction furnace with different molybdenum and tungsten contents. The produced steel were hot forged at 950 °C – 1100 °C, followed by air cooling. The ordinary heat treatment was applied through austenizing at 1050 °C for one hour followed by water quenching and then, they were tempered at 700 °C for 2 hours. Optical microscope, Scanning Electron Microscope (SEM), and EDX were used to investigate the microstructure and precipitated phases after complete heat treatment process. In addition, Thermo-Calc program was used to predict the phases which may be formed. The results showed that replacement of molybdenum by tungsten has an effect on the solubility of different intermetallic phases at high temperature, delaying the deteriorative Z-phase.

scholarly journals Determination of Critical Transformation Temperatures for the Optimisation of Spring Steel Heat Treatment Processes

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1014
Author(s):  
Velaphi Jeffrey Matjeke ◽  
Josias Willem van der Merwe ◽  
Nontuthuzelo Lindokuhle Vithi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Treatment Process ◽  
Thermal Transformation ◽  
Optical Microscope ◽  
Spring Steel ◽  
Heat Treatment Process ◽  
Cooling Rates ◽  
Transformation Temperatures

Bogie spring performance can be improved by using the exact heat treatment process parameters. The purpose of the study is to determine the critical transformation temperatures and investigate the effect of the cooling rates on microstructural and mechanical properties. The precise determination of the required cooling rates for the particular grade of steel is important in order to optimise the heat treatment process of heavy-duty compression helical spring manufacturing. A traditional heat treatment system for the manufacture of hot coiled springs requires heating the steel to homogenize austenite; then, it is decomposed to martensite by rapid cooling. By analyzing the transition properties by heating and differing cooling rates, this analysis examines the thermal behaviour of high strength spring steel. Using the dilatometer and differential scanning calorimeter, scanning electron microscope, optical microscope, and hardness checking, critical transition temperatures and cooling rates of three springs steels were measured. Although the thermal transformation of materials has been researched for decades using dilatometers, not all materials have been characterized. The research offers insights into the critical transformation temperatures for the defined grades of spring steel and the role of cooling rates in the material’s properties. Mechanical properties are influenced by the transition data obtained from the dilatometric analysis.

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