Research on the Effective Rules for the Impact Toughness and Hardness of Austempered Ductile Iron (ADI) by Austempering Parameters

2014 ◽  
Vol 488-489 ◽  
pp. 3-8 ◽  
Author(s):  
Gao Lian Shi ◽  
Shao Hua Wu ◽  
Xu Hong Guo ◽  
Xing Huang

With the common engineering-purpose ductile iron used as research subject, the research on rules of austempering parameters to influence the impact toughness and hardness of austempered ductile iron (ADI) was implemented in this paper by adopting the combination of theoretical, experimental and numerical simulation methods, and setting series of austempering parameters; After the impact tests and hardness tests simulated by the finite element software - ANSYS Workbench, the simulation data were analyzed by comparing with the experimental data. The experimental results showed that: austenitizing time was longer, ADI hardness was smaller while impact toughness remained unchanged; hardness was in linearly-decreasing trend with rise of austempering temperature, while impact toughness first increased and then decreased as the austempering temperature rose, with the maximum at the temperature 350°C; The effect of austempering time on the impact toughness was very few; extension of austempering time allows the hardness to increase slightly, but only a little.

2011 ◽  
Vol 284-286 ◽  
pp. 1085-1088 ◽  
Author(s):  
Jin Hai Liu ◽  
Guo Lu Li ◽  
Xue Bo Zhao ◽  
Xiao Yan Hao ◽  
Jian Jun Zhang

The microstructure and properties of austempered ductile iron with carbides was studied to increase the abrasive resistance of ADI. It was proven that the austempering temperature influences greatly the microstructure, impact toughness, hardness and abrasion resistance of CADI. With increase of austempering temperature, the acicular ferrite becomes thicker and bigger, the impact toughness rises, and the hardness decreases. But there is a complicated effect of austempering temperature on wet abrasion resistance. In addition, the CADI grinding balls were cast and the field testing was performed. The CADI ball is one third of abrasion loss of low chromium cast iron, zero rate of breakage and no loosing round.


2011 ◽  
Vol 418-420 ◽  
pp. 1768-1771 ◽  
Author(s):  
Bulan Abdullah ◽  
Siti Khadijah Alias ◽  
Ahmed Jaffar ◽  
Rashiddy Wong Freddawati ◽  
A. Ramli

The effect of different austempering holding times on the hardness and impact toughness of 0.254% niobium alloyed austempered ductile iron was investigated in this study. Molten ductile iron was prepared in an induction furnace with capacity of 60kg. Samples with dimension of 300m x Ø25mm in form of Y block double cylinder was constituted and solidified samples were then machined in accordance to ASTM E23 for impact test specimens. Samples were ground and polished before Rockwell hardness test was conducted. Austempering heat treatment process with austenitizing temperature of 900°C for 1 hour and austempering temperature of 350°C for 1 hour, 2 hours and 3 hour holding times were then carried out. The results from this research indicated that austempering the sample for 1 hour resulted in significant improvement of the impact toughness values but increasing the austempering holding time deficiently reduced the values. On the contrary, the hardness of niobium alloyed austempered ductile iron continues to increase with respect to longer austempering holding times.


2021 ◽  
Vol 8 (1) ◽  
pp. 1939928
Author(s):  
Ananda Hegde ◽  
Gurumurthy B M ◽  
Jamaluddin Hindi ◽  
Sathyashankara Sharma ◽  
Gowrishankar M C

2019 ◽  
Vol 8 (2) ◽  
pp. 36
Author(s):  
Abel. A. Barnabas ◽  
Akinlabi Oyetunji ◽  
S. O. Seidu

In this research, Scanning Electron Microscope (SEM) analysis was conducted on the produced antimony modified carbidic austempered ductile iron for agricultural implement production. Six different alloys of carbidic austempered ductile iron with varying micro quantities of antimony elements were produced. The produced alloys were heated to austenitic temperature of 910oC, held at this temperature for 1 hour, finally subjected to austempering temperatures of 300°C and 325°C for periods of 1-3 hours. The SEM in conjunction with XRD and EDS was used for the analysis. Microstructural phase morphology, phase constituents and phase compositions were viewed with SEM, XRD and EDS respectively. The results show that various phases such as spiky graphite, blocky carbides, granular carbide, pearlite and ausferrite matrix. The XRD pattern revealed some compounds such as (Fe, Cr)3C, (primary carbide), Cr6C23 (few secondary carbide), (NiFe2O4), chromite (FeCr2O4), Cr7C3 (few eutectic carbide) and Cr3Ni2. In conclusion, it was observed in terms of morphology that chunky graphite, blocky carbide and pearlite phases were present in the cast carbidic ductile iron (CDI) without antimony addition. The CDI with varying quantities of antimony additions shows spiky graphite, granular carbides and pearlite matrix. After the samples were subjected to austempering processes, all the phases were found to be intact except the pearlite phase that transformed to ausferrite phase. The antimony element in the alloys was seen to promote the formation of pearlite phase intensively. The hardness of the samples increases as the antimony addition increases from 0.096wt.% to 0.288wt.% owing to the increase in pearlite phase, while the impact toughness reaches relatively high level, when 0.288wt.% antimony was added, probably due to the refinement of graphite nodules. All the results obtained showed that appropriate content of antimony addition plays an important role in increasing the nucleation rate of graphite nodules, and also lead to improvement in carbide formation thereby providing good balance between wear and impact properties.


2019 ◽  
Vol 35 (11) ◽  
pp. 1329-1336 ◽  
Author(s):  
Chengduo Wang ◽  
Ruizhuo Liu ◽  
Songjie Li ◽  
Chang Gu ◽  
Xueshan Du ◽  
...  

Author(s):  
T. R. Uma ◽  
J. B. Simha ◽  
K. Narasimha Murthy

Laboratory abrasive wear tests have been reported on permanent moulded toughened austempered ductile iron. The influence of austempering temperature on the abrasive wear behavior have been studied and discussed. The results indicate that with increase in austempering temperature from 300°C to 350°C, the abrasive wear resistance increased, and as the austempering temperature increased to 400°C, there was reduction in the abrasive wear resistance. These results have been interpreted based on the structural features and graphite morphology.


2020 ◽  
Vol 835 ◽  
pp. 163-170
Author(s):  
Hayam A. Aly ◽  
Adel Nofal ◽  
Abdel Hamid A. Hussein ◽  
Elsayed M. El-Banna

This study aimed at optimizing impact toughness and high wear resistant carbidic austempered ductile iron (CADI) by controlling the morphology, size and quantity of carbides. The effects of dynamic solidification, niobium addition, combined action of them and heat treatment have been investigated. Investigations were performed by means of the image analyzer, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray diffraction. Impact toughness, hardness and abrasion wear resistance tests were conducted. Fracture surfaces were studied. Results indicated that microstructural control during solidification is the most valuable tool to attain the optimum combination between impact toughness and wear resistance in CADI. Combined action of Nb addition and dynamic solidification improves impact toughness, hardness and wear resistance even more than the action of each individual factor. In the as-cast condition, impact toughness, hardness and abrasion resistance were improved after dynamic solidification compared to statically solidify one by 31.2%, 18.75% and 87.96% respectively. This enhancement was increased to 36.9%, 25.93% and 128. % by adding 1% Nb. Lower tempering temperature of 275°C exhibit best hardness and abrasion resistance better than higher tempering temperature of 375°C.


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