scholarly journals Effects of Magnesium Variation and Heat Treatment on Mechanical and Micro-Structural Properties of Ductile Cast Iron

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Abdullahi O Adebayo ◽  
Gabriel L Taiwo ◽  
Akinlabi Oyetunji
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Structural Properties ◽  
Mechanical Test ◽  
Rotary Furnace ◽  
Salt Bath ◽  
Mechanical Tests ◽  
Ductile Cast Iron ◽  
Relative Reduction ◽  
Two Samples

The effects of magnesium variation and austempering heat treatment on mechanical and microstructural properties of ductile iron produced using the rotary furnace were investigated. Varied quantity of magnesium-ferrosilicon in the range of 0.03 % to 0.06 % were used as nodulirizer to treat 4 kg mass of molten metal per ladle by sandwich process and poured into sand mould.  Mechanical test (tensile, hardness, fatigue, impact and wear) and micro-structural examinations were carried out on the four samples produced. Samples C and D of 0.056% and 0.061% magnesium showed an improvement in their micro-structural properties due to the presence of more graphite nodules. Hence, they were observed to have exhibited better tensile strength of 598.07MPa and 609.03MPa. The fatigue strength also increased to 501.91MPa and 509.27MPa respectively. These two samples were further subjected to austempering heat treatment by heating to 850ºC for austenitization and soaked for homogenization for one hour at the temperature before quickly transferred into a salt bath of 50 % NaNO3 : 50 % NaCl maintained at 3600C and quenched for transformation for 1 hour before finally air cooled. Mechanical tests and micro-structural examinations were thereafter carried out. Sample C had an outstanding increase in tensile strength, from 598.07MPa to 891.22MPa, while specimen D increased from 609.03MPa to 898.76MPa. The results of abrasion test indicated that samples C and D had abrasion resistance increase from 2.20×10¹¹m² and 2.39×10¹¹m² to 2.35×10¹¹m² and 2.68×10¹¹ m² respectively after austempering. There were also relative increase in fatigue resistance and impact toughness for the two samples but with relative reduction in hardness from 47.7 to 44.2 and 50.3 to 47.4.

scholarly journals Impact of Molybdenum on Heat-Treatment and Microstructure of ADI

2018 ◽  
Vol 925 ◽  
pp. 188-195 ◽  
Author(s):  
Julius Alexander Gogolin ◽  
Babette Tonn
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Transition Point ◽  
Outer Part ◽  
Isothermal Transformation ◽  
Mechanical Tests ◽  
High Tensile Strength ◽  
Manufacturing Costs ◽  
Nickel Copper ◽  
Quenching Process

Austempered Ductile Iron (ADI) is characterized by high tensile strength with acceptable ductility. Steel, as a large competitor to ADI, also meets the tensile and yield strength. Nevertheless, the main advantages of ADI compared to steel are the lower density (7.2 g/cm3 to 7.85 7.87 g/cm3) for weight reduction and lower manufacturing costs because of less energy consumption during the production. One of the main problems of producing ADI is the quenching process during heat treatment of thick-walled castings. The inner part of a massive casting – in contrast to the outer part – cools down more slowly, resulting in a heterogeneous microstructure with parts of pearlite and ferrite embedded in austenite before reaching the isothermal transformation temperature. Molybdenum is, besides nickel, copper and manganese, one of the possible alloying elements that postpone the transition point of ferrite and/or pearlite. To investigate the influence of molybdenum in thick-walled castings experiments with different molybdenum contents were performed. In dependence on the molybdenum content, different austenisation and ausferritisation temperatures and times are examined in order to investigate the transformation points, fraction and morphology of different phases. The mechanism of molybdenum in ADI has been investigated by means of dilatometer tests, microstructure analysis and mechanical tests.

scholarly journals Microstructure and Mechanical Characterization of Austempered AISI 1018 Steel

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Muideen Bodude ◽  
Oluwole D Adigun ◽  
Ahmed Ibrahim
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Impact Energy ◽  
Microstructural Analysis ◽  
Salt Bath ◽  
Isothermal Transformation ◽  
Critical Conditions ◽  
Average Value ◽  
Extreme Load ◽  
Bainite Microstructure

AISI 1018 mild steels are widely used for engineering applications in machine components and for structural purposes. These materials suffer mechanical damages especially when used under critical conditions of extreme load. In this study, the effect of austempering heat-treatment on the hardness, tensile strength, impact energy and the microstructure of AISI 1018 steels were evaluated. The steel specimens were subjected to austempering heat-treatment by austenitizing at a temperature of 830°C, maintained at this temperature for a period of 1 hour 30 minutes, before rapidly cooled down in a NaNO3 salt bath maintained at 300°C for isothermal transformation for a further 50 minutes before finally cooled down to room temperature. Microstructural analysis using Scanning Electron Microscope (SEM) shows transformation from ferrite/pearlite to bainite microstructure. The tensile strengths of the specimen increased from 400 MPa to 500 Mpa; hardness increased from an average value of 140Rc to 162Rc; while impact energy increased from 15.6 Joule to 30.6 Joule by the austempering heat-treatment. Keywords—Austempering, hardness, tensile strength, impact energy, microstructure

scholarly journals Investigation of jatropha seed oil as austempering quenchant for ductile cast iron

2014 ◽  
Vol 3 (3) ◽  
pp. 387
Author(s):  
Akor Terngu ◽  
Gundu David Terfa
Keyword(s):  
Heat Treatment ◽  
Cast Iron ◽  
Seed Oil ◽  
Salt Bath ◽  
Ductile Cast Iron ◽  
Isothermal Heat Treatment ◽  
Quenching Medium ◽  
Appreciable Increase ◽  
Conventional Heat Treatment ◽  
Jatropha Seed

Austempering is a multi-step process that includes austenitizing, followed by cooling rapidly enough to avoid the formation of pearlite to a temperature above the martensite start (Ms) and then holding until the desired microstructure is formed. It is an isothermal heat treatment process that, when applied to cast iron, produces components that, in many cases, have properties superior to those process by conventional heat treatment. Salt bath has been recognized as the conventional quenching medium for austempering. This study investigates the suitability of jatropha seed oil as quenching medium for asaustempering ductile cast iron. Test samples were austenitized at 9500C; socked for 1hr; austempered for varying periods of 1, 2, 3, 4 and 5hrs. The result showed significant increase in tensile strength and impact energy apart from achieving an appreciable increase in hardness. It also tally with recommended values of ductile cast iron austempered in salt bath, implying that jatropha oil can be used as hot bath for the austempering of ductile cast iron. Keywords: Ausferrite, Austempering, Austenitized, Matrix So, Cked.

Mechanical Properties of Concrete Added with Chicken Rachis as Reinforcement

2011 ◽  
Vol 147 ◽  
pp. 37-41 ◽  
Author(s):  
Ezahtul Shahreen Ab Wahab ◽  
Siti Fatimah Che Osmi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Mechanical Test ◽  
Plain Concrete ◽  
Mechanical Tests ◽  
Control Specimen ◽  
Chicken Feather ◽  
Cement Concrete ◽  
Concrete Mix

This investigation was carried out to look the possibility of using chicken rachis as reinforcement in concrete mix. In this study, two different percentage of rachis from chicken feather were added to plain concrete comprises of 1% and 2% from the total weight of cement. Concrete with grade 30 were formed by using chicken rachis as additive material. Selected mechanical test were performed and the results were analysed. The mechanical tests included compressive strength, and splitting tensile strength. Comparison was made of these values and those of control specimen (without chicken rachis). The results showed an increment on strength for all mechanical tests done using concrete added with 1% chicken rachis compared to 2% chicken rachis added and those control specimens.

Tensile Strength Properties of Niobium Alloyed Austempered Ductile Iron on Different Austempering Time

2012 ◽  
Vol 457-458 ◽  
pp. 1155-1158 ◽  
Author(s):  
Bulan Abdullah ◽  
Siti Khadijah Alias ◽  
A. Jaffar ◽  
Abd Amirul Rashid ◽  
M. Haskil ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Ductile Iron ◽  
Salt Bath ◽  
Strength Properties ◽  
Austempered Ductile Iron ◽  
Bath Furnace

This study focused on tensile strength properties inclusive of ultimate tensile strength and elongation values of niobium alloyed ductile iron in as cast and austempered conditions. The tensile specimens were machined according to TS 138 EN 10002-1 standard. Austempering heat treatment was conducted by first undergoing austenitizing process at 900°C before rapidly quenched in salt bath furnace and held at 350°C for 1 hour, 2 hours and 3 hours subsequently. The findings indicated that austempering the samples for 1 hour had resulted in improvement of almost twice of the tensile strength in niobium alloyed ductile iron. Improvement of elongations values were also noted after 1 hour austempering times. Increasing the austempering holding times to 2 hour and 3 hours had resulted in decrement in both tensile strength and elongations values.

scholarly journals An Investigation into Mechanical Properties of Ductile Cast Iron with Different Heat Treatment Processes

2019 ◽  
Vol 63 (3) ◽  
pp. 183-187
Author(s):  
Romany R. Moussa ◽  
Amer E. Ali ◽  
Ragab K. Abdel-Magied ◽  
Mohamed N. Elshiekh
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Iron ◽  
Wear Rate ◽  
Experimental Tests ◽  
Mechanical Tests ◽  
Heat Treatments ◽  
Ductile Cast Iron ◽  
Treatment Processes ◽  
Heat Treated

The mechanical properties as well as microstructure of the ductile cast iron (DCI) are most likely affected by heat treatments. In this work, the mechanical properties of different heat treated of DCI alloy were investigated. Two heat treatment (HT) processes were conducted for DCI; austempering and quenching followed by lower tempering. The melted alloy of DCI was poured in Y-block, from which the specimens of the mechanical tests were prepared. Experimental tests were carried out to investigate the effect of these HT processes on the mechanical properties. A comparison between mechanical properties due to HT and as cast DCI are presented and discussed. The results showed that there is a difference in microstructure, homogeneity, wear rate and compression of DCI based on the conducted heat treatment.

The Effect of Intermediate Annealing Condition on Recrystallization Behavior in Continuous Cast Al-Mn Alloy

2014 ◽  
Vol 794-796 ◽  
pp. 1251-1256
Author(s):  
Kenta Suzuki ◽  
Tomohiro Sasaki ◽  
Toshiya Anami
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Tensile Strength ◽  
Rapid Heating ◽  
Salt Bath ◽  
Grain Structure ◽  
Annealing Condition ◽  
Recrystallization Behavior ◽  
Intermediate Annealing ◽  
Continuous Cast

Favorable features such as finer particles and supersaturated solid solution are characterized in continuous casting. In this study, difference of recrystallization behavior was mainly evaluated on two intermediate annealing conditions in continuous cast Al-Mn alloy. One annealing condition was air furnace annealing which corresponds to batch type annealing and is conventionally used to anneal aluminum alloys. Another one was salt bath annealing which simulates CAL type annealing, which is characterized by shorter holding time with rapid heating and cooling. With consideration for application to fin stock in heat exchanger, heat treatment simulating brazing at 600°C was carried out on cold rolled sheets after respective intermediate annealing. After the brazing heat treatment, superior tensile strength and coarser grain structure were attractively obtained with the salt bath intermediate annealed fin. This tensile strength was correlated with much finer particles and more solid solution confirmed after the salt bath intermediate annealing. The coarser grain structure would be brought by changing in recovery and recrystallization behavior during brazing heat treatment.

scholarly journals TENSILE TEST TO STUDY THE QUALITY OF REINFORCING STEEL BARS

2021 ◽  
pp. 50-60
Author(s):  
Mufida Mohamed Bey ◽  
Ezeddin H. Alshbuki ◽  
Rawad Ahmed Krayem
Keyword(s):  
Tensile Strength ◽  
Tensile Test ◽  
Mechanical Test ◽  
Testing Machine ◽  
Reinforcing Steel ◽  
Yield Strain ◽  
Tensile Testing Machine ◽  
Engineering Strain ◽  
Two Samples ◽  
Steel Bars

In this research, samples of locally manufactured and imported reinforcing steel with different diameters 14 and 16 mm were studied by conducting tensile test, which is an important mechanical test to know the properties of mechanical materials and study their behaviour by under loading two samples of each type using a general tensile testing machine type (SHUMIDUZ –UH2000). The results obtained from this test were used to find a set of properties represented in the ultimate tensile strength (σUTS), yield strength or yield point (σy), yield strain(e), and maximum strain (eMax), and there was a set of properties such as elastic modulus (E), Toughness modulus (T) and modulus of Resilience (Ur) that were mathematically calculated. The real stress and real strain for all samples were calculated too. The engineering stress and the engineering strain were presented by drawing the curves in order to show the difference. The results obtained from the tensile test showed that all samples were of steel reinforcement with protrusions of an average resistance (T30) where the yield stress values were 340-406 N/mm2, and the tensile strength values were 574-673 N/mm2which conforms to the Libyan Standard No. 75 of 2013 for concrete reinforcing steel bars. The results also showed the convergence of local samples with the imported samples.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

VASCOMAX T-300

Alloy Digest ◽  
1990 ◽  
Vol 39 (12) ◽  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
High Temperature ◽  
Heat Treating ◽  
Vacuum Arc ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Vacuum Arc Remelting ◽  
Temperature Performance

Abstract VASCOMAX T-300 is an 18% nickel maraging steel in which titanium is the primary strengthening agent. It develops a tensile strength of about 300,000 psi with simple heat treatment. The alloy is produced by Vacuum Induction Melting/Vacuum Arc Remelting. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-454. Producer or source: Teledyne Vasco.

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