scholarly journals Influence of Austempering Temperatures on the Microstructure and Mechanical Properties of Austempered Ductile Cast Iron

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 967
Author(s):  
Regita Bendikiene ◽  
Antanas Ciuplys ◽  
Ramunas Cesnavicius ◽  
Audrius Jutas ◽  
Aliaksandr Bahdanovich ◽  
...  

The influence of the austempering temperatures on the microstructure and mechanical properties of austempered ductile cast iron (ADI) was investigated. ADI is nodular graphite cast iron, which owing to higher strength and elongation, exceeds mechanical properties of conventional spheroidal graphite cast iron. Such a combination of properties is achieved by the heat treatment through austenitization, followed by austempering at different temperatures. The austenitization conditions were the same for all the samples: temperature 890 °C, duration 30 min, and quenching in a salt bath. The main focus of this research was on the influence of the austempering temperatures (270 °C, 300 °C, and 330 °C) on the microstructure evolution, elongation, toughness, and fatigue resistance of ADI modified by certain amounts of Ni, Cu, and Mo. The Vickers and Rockwell hardness decreased from 535.7 to 405.3 HV/1 (55.7 to 44.5 HRC) as the austempering temperature increased. Optical images showed the formation of graphite nodules and a matrix composed of ausferrite; the presence of these phases was confirmed by an XRD diffraction pattern. A fracture surface analysis revealed several types of the mechanisms: cleavage ductile, transgranular, and ductile dimple fracture. The stress-controlled mechanical fatigue experiments revealed that a 330 °C austempering temperature ensures the highest fatigue life of ADI.

2003 ◽  
Vol 44 (7) ◽  
pp. 1419-1424 ◽  
Author(s):  
Sadato Hiratsuka ◽  
Hiroshi Horie ◽  
Toshinori Kowata ◽  
Katsumi Koike ◽  
Kazumichi Shimizu

2021 ◽  
Vol 12 ◽  
pp. 2414-2425
Author(s):  
Wilson Sckudlarek ◽  
Manar N. Krmasha ◽  
Kassim S. Al-Rubaie ◽  
Orlando Preti ◽  
Julio C.G. Milan ◽  
...  

2009 ◽  
Vol 50 (9) ◽  
pp. 2207-2211 ◽  
Author(s):  
Chang-Yong Kang ◽  
Kwang-Hee Lee ◽  
Hae Ryong Jung ◽  
Gwang-Ho Kim ◽  
Byoung-Suhk Kim ◽  
...  

Author(s):  
Dhruv Patel ◽  
Devendra Parmar ◽  
Siddharthsinh Jadeja

Microstructural adaptation of cast iron alloys by inoculation is a well-known practice to swell their mechanical properties. In foundries, several inoculants have been used to refine grain structure, and to obtain uniform distribution of graphite flakes. Inoculation is one of the most critical steps in cast iron production. The effectiveness of inoculants depends on melt temperature, method of addition, type of inoculants, and holding time. In this paper, the effect of Ca-based, Ba-based, Ca-Ba based and Sr-based inoculants on microstructure and tensile properties of grey cast iron IS-210 and spheroidal graphite iron IS-1862 is reported. Results showed both Ca and Ba based inoculants were effective in obtaining uniform distribution of flaky and nodular graphite in IS-210, and IS-1862 cast irons, respectively. But in a case of Sr-based inoculant were highly effective for increase the nodularity of SG cast iron as well as succeed supreme yield strength for both grey and ductile cast iron. The amounts of ferrite in the as-cast matrix are excess with controlled granulometry for elimination of primary carbide in Sr-based inoculant.


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