General Properties of Non-alloyed Grey Cast Irons (or Low Alloy) and Flake Graphite

Pearlitic flake-graphite grey cast irons have long been widely used for the manufacture of diesel-engine combustion-chamber components. Nonetheless, very few pertinent high-temperature data are to be found in published work. The investigation described attempts to enlarge current knowledge on the high-temperature behaviour of grey cast irons in view of requirements highlighted by high thermal ratings. A general consideration of the problem showed that the often quoted Eichelberg material-quality factor is largely irrelevant and an alternative assessment formula is proposed. This is broadly confirmed by a systematic examination of the mechanical and physical properties of 166 plain and alloyed cast irons and a limited number of engine components. Different engine components impose different demands upon the material properties but for economic reasons a single cast-iron melt capable of meeting most of the requirements of all components is needed. It is shown that this situation is best met with an alloyed iron containing 1.3 per cent of copper-nickel and 0.4 per cent of molybdenum. The scatter in properties obtained from production casts was found to be typical for such irons. For components having safety factors of 2 or less, a prerequisite of economic engineering design, the service reliability is crucially dependent upon the scatter of material properties. Thus, there are advantages in reducing this scatter and it is shown that this can be achieved by attention to the cleanliness of the matrix and tight control of the chemistry of the melt. In general, the absolute values of mechanical and physical properties of flake-graphite cast irons appear to be governed mainly by the form and size of the graphite flakes and the chemistry of the matrix (i.e. CEV and alloying additions). Regression analysis of the results permitted the derivation of empirical formulae for the prediction of the iron properties. The general findings are used to suggest possible ways of improving the thermal resistance.

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Structure Distribution in Precise Cast Iron Moulded on Meltable Model

Archives of Foundry Engineering ◽

10.1515/afe-2015-0082 ◽

2015 ◽

Vol 15 (4) ◽

pp. 69-74 ◽

Cited By ~ 1

Author(s):

B. Skrbek ◽

K. Policar

Keyword(s):

Quality Improvement ◽

Cast Iron ◽

Ductile Cast Iron ◽

Spheroidal Graphite ◽

Flake Graphite ◽

Cast Irons ◽

Remanent Magnetism ◽

Measurement Results ◽

Mechanical And Physical Properties ◽

Grey Cast

Abstract Topic of this work is to compare metalurgy of cast irons poured into sand moulds and into shell molds at IEG Jihlava company and from it following differencies in structures of thin- and thick-walled castings. This work is dealing with investigation and experimental measurement on surfaces and sections suitable thin- and thick-walled investment castings at IEG Jihlava. Cast irons with flake graphite (grey cast iron) and cast irons with spheroidal graphite (ductile cast iron). Both mechanical and physical properties are determined using calculations from as measured values of wall thicknesses L and Lu, Vickers hardness and remanent magnetism. Measurement results are discussed, findings are formulated and methods for castings metallurgical quality improvement are recommended finally.

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Role of Lanthanum in Graphite Nucleation in Grey Cast Iron

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.457.19 ◽

2010 ◽

Vol 457 ◽

pp. 19-24 ◽

Cited By ~ 9

Author(s):

Iulian Riposan ◽

Mihai Chisamera ◽

Stelian Stan ◽

Eduard Stefan ◽

Cathrine Hartung

Keyword(s):

Flake Graphite ◽

Nucleation Process ◽

Cast Irons ◽

Active Elements ◽

Nucleation Sites ◽

Phase Complex ◽

Grey Cast ◽

Scanning Electron ◽

Grey Iron

Specific investigations concerning La-contributions in graphite nucleation process in Ca,Al,La-FeSi inoculated grey cast irons were performed by using a scanning electron microscopy (SEM, EDS). It was re-confirmed that complex (Mn,X)S compounds act as major nucleation sites for graphite flakes. La was mainly concentrated in the first formed oxide-based micro-inclusions (similarly to Al), but also at an important level in the shell of (Mn,X)S compounds (accompanying Ca). It is assumed that La forms micro-inclusions later than Al, as La-reached phase surrounded Al-reached phase. Complex Al-La small micro-inclusions, as possible better nucleation sites for (Mn,X)S compounds and La-Ca presence in the shell/body of these sulphides, possible better nucleation sites for flake graphite, appear to be the peculiar effects of ferrosilicon based inoculants, which include these active elements, promoting type-A graphite, inclusively in low S-grey iron.

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Founding. Grey cast irons

10.3403/01167911 ◽

1997 ◽

Keyword(s):

Cast Irons ◽

Grey Cast

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Grey cast irons. Classification

10.3403/30354759u ◽

2020 ◽

Keyword(s):

Cast Irons ◽

Grey Cast

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Grey cast irons. Classification

10.3403/30354759 ◽

2019 ◽

Keyword(s):

Cast Irons ◽

Grey Cast

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Ce-Bearing FeSi Alloy Inoculation of Electrically Melted, Low Sulphur Grey Cast Irons for Thin Wall Castings

Metals ◽

10.3390/met11071122 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1122

Author(s):

Irina Varvara Balkan ◽

Iulian Riposan

Keyword(s):

Wall Thickness ◽

Structural Characteristics ◽

Cooling Curve ◽

Thin Wall ◽

Cast Irons ◽

Iron Castings ◽

Grey Cast ◽

The Difference ◽

Thermal Cooling ◽

Fesi Alloy

Electrically melted and over-heated (>1500 °C) grey cast iron at less than 0.04%S, as commonly used, solidifies large amounts of carbides and/or undercooled graphite, especially in thin wall castings; this is necessary to achieve a stronger inoculation. The efficiency of Ce-bearing FeSi alloy is tested for lower ladle addition rates (0.15 and 0.25 wt.%), compared to the base and conventional inoculated iron (Ba,Ca-bearing FeSi alloy). The present work explores chill and associated structures in hypoeutectic grey iron (3.6–3.8%CE, 0.02%S, (%Mn) × (%S) = 0.013–0.016, Alres < 0.002%), in wedge castings W1, W2 and W3 (ASTM A 367, furan resin sand mould), at a lower cooling modulus (1.1–3.5 mm) that is typically used to control the quality of thin wall iron castings. Relatively clear and total chill well correlated with the standard thermal (cooling curve) analysis parameters and structural characteristics in wedge castings, at different wall thickness, displayed as the carbides/graphite ratio and presence of undercooled graphite morphologies. The difference in effects of the two inoculants addition is seen as the ability to decrease the amount of carbides and undercooled graphite, with Ce-bearing FeSi alloy outperforming the conventional inoculant, especially as the wall thickness decreased. It appears that Ce-bearing FeSi alloy could be a solution for low sulphur, electric melt, thin wall iron castings production.

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