scholarly journals Influence of austempering temperature and salt bath agitation on microstructure and mechanical properties of austempered ductile iron

2018 ◽  
Vol 56 (03) ◽  
pp. 137-144
Author(s):  
N. CATIPOVIC ◽  
D. ŽIVKOVIĆ ◽  
Z. DADIĆ ◽  
J. KROLO
Author(s):  
Nikša Čatipović ◽  
Dražen Živković ◽  
Zvonimir Dadić ◽  
Marin Viceić

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.


2014 ◽  
Vol 592-594 ◽  
pp. 192-196
Author(s):  
R. Prem Kumar ◽  
S.S. Mohamed Nazirudeen ◽  
J. Anburaj

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.


Author(s):  
Giulliana Victória Tissi ◽  
Gláucio Soares Da Fonseca

Austempered Ductile Iron (ADI) has excellent mechanical properties related to its microstructure ausferrite, and with the cycle of austempering heat treatment, many mechanical properties can be obtained from the same alloy, simply changing the time and temperature. To evaluate the influence of austempering time and temperature on the ADI, analyzed the modifications in the microstructures and mechanical properties of the samples of ductile iron, subjected to austempering heat treatment with austenitizing time and temperature of 910 °C and 90 minutes and during the austempering bath, the samples were submitted to different temperatures, 300, 320, 340, 360 e 380 °C, and for four different times for each temperature, 75, 110, 145 and 180 minutes. For the microstructural analysis, the microscopic techniques were used: optical and scanning electron and mechanical properties were obtained by mechanical testing of hardness and impact. The results show that there is a relationship between austempering temperature with microstructure and mechanical properties. The highest retained austenite and energy absorbed were 25.73% and 130 J, respectively, for the austempered sample at 380 °C and 180 minutes and the highest hardness value was 458 HB for the austempered sample at 300 °C and 75 minutes.  


MESIN ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Sulardjaka Sulardjaka ◽  
Yusuf Umardani ◽  
Agus Suprihanto

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.


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