Effects of titanium addition and section size on microstructure and mechanical properties of compacted graphite cast iron

This paper is concerned with the investigation of the effect of magnesium to sulfur ratio on the graphite morphology and estimation of the ranges of this ratio use to produce graphite cast iron at different section sections. The main factors affecting shape of graphite cast iron are the metallurgical structures and the section thicknesses. Cast iron of different shapes of graphite particles directly affect its thermo-mechanical properties. The nodular shape of these graphite particles such as in ductile cast iron improve its mechanical properties, on the other hand, when the shape of these graphite particles become elongated such as in flake graphite cast iron results in improving its thermal conductivity. In between, the worm-like shape of these graphite particles such as in compacted graphite cast iron, make this type of cast iron to have thermo-mechanical properties in between those of ductile and flake graphite cast iron. The different types of ductile , compacted and flake graphite cast iron were produced by means of plunger method at different section thicknesses and the effect of Mg/S ratio on these types of graphite particles was investigated and its range was established.

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Mechanical Properties of Compacted Graphite Cast Iron

10.4271/810209 ◽

1981 ◽

Cited By ~ 2

Author(s):

Gary F. Ruff

Keyword(s):

Mechanical Properties ◽

Cast Iron ◽

Compacted Graphite ◽

Graphite Cast Iron

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

Metals ◽

10.3390/met11060967 ◽

2021 ◽

Vol 11 (6) ◽

pp. 967

Author(s):

Regita Bendikiene ◽

Antanas Ciuplys ◽

Ramunas Cesnavicius ◽

Audrius Jutas ◽

Aliaksandr Bahdanovich ◽

...

Keyword(s):

Mechanical Properties ◽

Cast Iron ◽

Salt Bath ◽

Ductile Cast Iron ◽

Spheroidal Graphite ◽

Xrd Diffraction ◽

Microstructure And Mechanical Properties ◽

Graphite Cast Iron ◽

Austempering Temperature ◽

Austempered Ductile Cast Iron

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.

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