Effect of Chills on the Microstructure and Mechanical Properties of Carbidic Austempered Ductile Iron

2014 ◽  
Vol 592-594 ◽  
pp. 192-196
Author(s):  
R. Prem Kumar ◽  
S.S. Mohamed Nazirudeen ◽  
J. Anburaj
Keyword(s):  
Mechanical Properties ◽  
Ductile Iron ◽  
Salt Bath ◽  
Optical Microscope ◽  
Austempered Ductile Iron ◽  
The Third ◽  
Microstructure And Mechanical Properties ◽  
Three Samples ◽  
Recent Addition ◽  
Bath Furnace

Carbidic Austempered Ductile Iron (CADI) is a recent addition to the Austempered Ductile Iron (ADI) family. The effect of chills on the microstructure and mechanical properties of CADI was investigated after Austempering. Three samples of chromium alloyed CADI, the first sample without chill, the second sample with bottom chill and the third sample with bottom and side chills were produced in order to evaluate the effect of chills on its mechanical properties. The samples were austenised for 2 hours at 925° C and then austempered at 325° C for 2 hours in a salt bath furnace. The microstructural features of the as-cast and the austempered CADI samples were analysed using Optical Microscope and Scanning Electron Microscope (SEM). The mechanical properties of the CADI samples (as-cast and austempered) were evaluated for hardness, impact and wear. By austempering at 325° C for 2 hours a typical microstructure of bainite was produced in all the three samples. Hardness and wear resistance of austempered samples produced using bottom and side chills were considerably higher than the corresponding values in samples produced without using any chill and also by using only bottom chill. This enhanced mechanical property in the bottom and side chill sample is attributed to the presence of bainite, carbides and more of uniform fine graphite nodules.

scholarly journals Influence of the Salt Bath Agitation and Austempering Temperature on the Microstructure of Austempered Ductile Iron

2017 ◽  
Author(s):  
Nikša Čatipović ◽  
Dražen Živković ◽  
Zvonimir Dadić ◽  
Marin Viceić
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Ductile Iron ◽  
Salt Bath ◽  
Austempered Ductile Iron ◽  
Toughness Test ◽  
Microstructure And Mechanical Properties ◽  
Heat Treated ◽  
Final Microstructure ◽  
Austempering Temperature

In this paper the influence of austempering temperature and salt bath agitation on the final microstructure and mechanical properties of the ferritic ductile iron were studied. 17 samples had been subjected to different heat treatment parameters. Different microstructures were recorded upon the completion of the tests. From the obtained micro images, it is obvious that both the austempering temperature and salt bath agitation affect the final microstructure of the austempered ductile iron. Lower austempering temperatures and salt bath agitation produce more ausferrite in the microstructure, hence the harder and tougher phases are present. This was confirmed with hardness and toughness test of the 17 heat-treated samples. Lower austempering temperatures give more ausferrite phase and therefore higher hardness, but hardness decreases with increasing austempering temperatures. Toughness rises with rising austempering temperatures, but drops significantly with temperatures above 395°C because of the final microstructure.

Phase Transformations and XRD Analysis of Austempered Ductile Iron

2011 ◽  
Vol 402 ◽  
pp. 187-190
Author(s):  
Bulan Abdullah ◽  
S. K. Alias ◽  
A. Jaffar ◽  
M. F. Idham ◽  
A. Ramli
Keyword(s):  
Ductile Iron ◽  
Casting Process ◽  
Lower Bainite ◽  
Xrd Analysis ◽  
Salt Bath ◽  
Austempered Ductile Iron ◽  
X Ray Diffraction ◽  
Upper Bainite ◽  
Cast Ductile Iron ◽  
Bath Furnace

This research penetrated on the transformation of phases in the microstructures of austempered ductile iron with respect to different austempering holding times. Ductile iron samples were constituted in form of Y block double cylinder with dimension of 300m x Ø25mm through CO2 sand casting process in 60 kg capacity furnace. Austempering process were conducted by first austenitizing the samples at temperature of 900°C for 1 hour. The process continues by rapidly quenched the samples inside salt bath furnace at 350°C for three different holding times of 1 hour, 2 hours and 3 hour. Samples were then taken out and cooled at room temperature. Samples were then prepared in accordance to standard metallographic process and observed using Tabletop Scanning Electron Microscopy (SEM) model Hitachi TM3000. Phases were then verified through X-Ray Diffraction analysis (XRD) test by Rigaku diffractometer. The phase structures of as cast ductile iron mainly consisted of graphite nodules embedded in ferrite and pearlite phases Austempering the samples for 1 hour holding time promoted the structures of ferrite platelets and bainitic structures surrounding the graphite. Longer austempering holding times resulted in coarsening of the ferrite platelets structures and transformation from lower bainite to upper bainite structures.

scholarly journals The Effect of Cu and Mo on Mechanical Properties and Corrosion Resistance of Austempered Ductile Iron

MESIN ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Sulardjaka Sulardjaka ◽  
Yusuf Umardani ◽  
Agus Suprihanto
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Ductile Iron ◽  
Brinell Hardness ◽  
High Strength ◽  
Hardness Test ◽  
Salt Bath ◽  
Austempered Ductile Iron ◽  
Immersion Corrosion ◽  
Mechanical Properties And Corrosion

The metal casting is the most economical manufacturing process. It can make products with complex geometries in one process. Austempered Ductile Iron (ADI) is a cast iron product that has high prospects for application, because ADI has a high strength closed to forged iron. The purpose of this study is to investigate the effect of addition of Cu and Mo on mechanical properties and corrosion resistance of ADI. Cu is added with percentages of 0.5 and 1% by weight, while Mo is added by percentages of 0.3 and 0.6% by weight. The austempering process is conducted on salt bath temperture 350 <sup>o</sup>C for 4 hours. The results of the process were characterized by hardness test, tensile test and corrosion resistance. Hardness and tensile strength of ADI were tested by Brinell hardness test based on ASTM E10 and ASTM E8 repectively. Corrosion resistance of ADI was tested by immersion corrosion testing based on ASTM G31 standard.  The results of this study indicate that the addition of Cu element significantly increases the strength of ADI. The addition of Mo element inhibits graphite nodularity and not significantly increases the mechanical properties. Addition of Mo increases corrosion resistance due the amount of retained austenite.

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.

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