Control of chilling tendency in grey cast iron reuse

In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is toward...

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Main Authors: Saliu Ojo Seidu, Iyiola Olatunji Ogunniyi
Format: Article
Language:English
Published: Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) 2013-02-01
Series:Materials Research
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392013000100018
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spelling doaj-b92c797130564924aae2f20ccccbfbd12020-11-24T20:49:05ZengAssociação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)Materials Research1516-14392013-02-01161145149Control of chilling tendency in grey cast iron reuseSaliu Ojo SeiduIyiola Olatunji OgunniyiIn grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation). With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test) with cooling modulus of 0.45 cm (W3½) and 0.54 cm (W4). The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (%) to 4.11 wt. (%)). In the W4 wedge sample, at 2.0 wt. (%) addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (%) addition. With equivalent aspect ratio (cooling modulus) in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392013000100018chillinggrey cast ironinoculationreuse
collection DOAJ
language English
format Article
sources DOAJ
author Saliu Ojo Seidu
Iyiola Olatunji Ogunniyi
spellingShingle Saliu Ojo Seidu
Iyiola Olatunji Ogunniyi
Control of chilling tendency in grey cast iron reuse
Materials Research
chilling
grey cast iron
inoculation
reuse
author_facet Saliu Ojo Seidu
Iyiola Olatunji Ogunniyi
author_sort Saliu Ojo Seidu
title Control of chilling tendency in grey cast iron reuse
title_short Control of chilling tendency in grey cast iron reuse
title_full Control of chilling tendency in grey cast iron reuse
title_fullStr Control of chilling tendency in grey cast iron reuse
title_full_unstemmed Control of chilling tendency in grey cast iron reuse
title_sort control of chilling tendency in grey cast iron reuse
publisher Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
series Materials Research
issn 1516-1439
publishDate 2013-02-01
description In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation). With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test) with cooling modulus of 0.45 cm (W3½) and 0.54 cm (W4). The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (%) to 4.11 wt. (%)). In the W4 wedge sample, at 2.0 wt. (%) addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (%) addition. With equivalent aspect ratio (cooling modulus) in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.
topic chilling
grey cast iron
inoculation
reuse
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392013000100018
work_keys_str_mv AT saliuojoseidu controlofchillingtendencyingreycastironreuse
AT iyiolaolatunjiogunniyi controlofchillingtendencyingreycastironreuse
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