Variation of carbon concentration in proeutectoid ferrite during austenitization in hypoeutectoid steel

Minsu Jung; Wontae Cho; Jihye Park; Jae Gil Jung; Young Kook Lee

doi:10.1016/j.matchar.2014.05.009

Variation of carbon concentration in proeutectoid ferrite during austenitization in hypoeutectoid steel

Minsu Jung, Wontae Cho, Jihye Park, Jae Gil Jung, Young Kook Lee

Department of Materials Science and Engineering

Research output: Contribution to journal › Article › peer-review

5 Citations (Scopus)

Abstract

The variation of the C concentration in proeutectoid ferrite (α_PF) during austenitization in hypoeutectoid steels was quantitatively investigated using the massive transformation start temperature (T_m) of α_PF to austenite (γ) measured by high-temperature confocal laser scanning microscopy and hardness of α_PF. The C concentration in α_PF at T _m in hypoeutectoid steels increased with increasing total C concentration up to approximately 0.2 wt.% during heating. The hardness of α_PF with isothermal holding time at 775 °C in S20C steel revealed C enrichment in α_PF at the early stage of isothermal holding and its reduction with further holding. These results explain the redistribution of the C in α_PF during austenitization as follows: free C atoms released from cementite during pearlite decomposition diffuse excessively into neighboring α_PF as well as pearlitic ferrite. The supersaturated C concentration in α_PF is reduced during the long-range diffusive transformation of α_PF to γ. However, some of the excess C atoms still remain in α_PF until α_PF starts to massively transform to γ.

Original language	English
Pages (from-to)	161-169
Number of pages	9
Journal	Materials Characterization
Volume	94
DOIs	https://doi.org/10.1016/j.matchar.2014.05.009
Publication status	Published - 2014 Aug

All Science Journal Classification (ASJC) codes

Materials Science(all)
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering

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10.1016/j.matchar.2014.05.009

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title = "Variation of carbon concentration in proeutectoid ferrite during austenitization in hypoeutectoid steel",

abstract = "The variation of the C concentration in proeutectoid ferrite (αPF) during austenitization in hypoeutectoid steels was quantitatively investigated using the massive transformation start temperature (Tm) of αPF to austenite (γ) measured by high-temperature confocal laser scanning microscopy and hardness of αPF. The C concentration in αPF at T m in hypoeutectoid steels increased with increasing total C concentration up to approximately 0.2 wt.% during heating. The hardness of αPF with isothermal holding time at 775 °C in S20C steel revealed C enrichment in αPF at the early stage of isothermal holding and its reduction with further holding. These results explain the redistribution of the C in αPF during austenitization as follows: free C atoms released from cementite during pearlite decomposition diffuse excessively into neighboring αPF as well as pearlitic ferrite. The supersaturated C concentration in αPF is reduced during the long-range diffusive transformation of αPF to γ. However, some of the excess C atoms still remain in αPF until αPF starts to massively transform to γ.",

author = "Minsu Jung and Wontae Cho and Jihye Park and Jung, {Jae Gil} and Lee, {Young Kook}",

year = "2014",

month = aug,

doi = "10.1016/j.matchar.2014.05.009",

language = "English",

volume = "94",

pages = "161--169",

journal = "Materials Characterization",

issn = "1044-5803",

publisher = "Elsevier Inc.",

}

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T1 - Variation of carbon concentration in proeutectoid ferrite during austenitization in hypoeutectoid steel

AU - Jung, Minsu

AU - Cho, Wontae

AU - Park, Jihye

AU - Jung, Jae Gil

AU - Lee, Young Kook

PY - 2014/8

Y1 - 2014/8

N2 - The variation of the C concentration in proeutectoid ferrite (αPF) during austenitization in hypoeutectoid steels was quantitatively investigated using the massive transformation start temperature (Tm) of αPF to austenite (γ) measured by high-temperature confocal laser scanning microscopy and hardness of αPF. The C concentration in αPF at T m in hypoeutectoid steels increased with increasing total C concentration up to approximately 0.2 wt.% during heating. The hardness of αPF with isothermal holding time at 775 °C in S20C steel revealed C enrichment in αPF at the early stage of isothermal holding and its reduction with further holding. These results explain the redistribution of the C in αPF during austenitization as follows: free C atoms released from cementite during pearlite decomposition diffuse excessively into neighboring αPF as well as pearlitic ferrite. The supersaturated C concentration in αPF is reduced during the long-range diffusive transformation of αPF to γ. However, some of the excess C atoms still remain in αPF until αPF starts to massively transform to γ.

AB - The variation of the C concentration in proeutectoid ferrite (αPF) during austenitization in hypoeutectoid steels was quantitatively investigated using the massive transformation start temperature (Tm) of αPF to austenite (γ) measured by high-temperature confocal laser scanning microscopy and hardness of αPF. The C concentration in αPF at T m in hypoeutectoid steels increased with increasing total C concentration up to approximately 0.2 wt.% during heating. The hardness of αPF with isothermal holding time at 775 °C in S20C steel revealed C enrichment in αPF at the early stage of isothermal holding and its reduction with further holding. These results explain the redistribution of the C in αPF during austenitization as follows: free C atoms released from cementite during pearlite decomposition diffuse excessively into neighboring αPF as well as pearlitic ferrite. The supersaturated C concentration in αPF is reduced during the long-range diffusive transformation of αPF to γ. However, some of the excess C atoms still remain in αPF until αPF starts to massively transform to γ.

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SN - 1044-5803

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SP - 161

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JO - Materials Characterization

JF - Materials Characterization

ER -

Variation of carbon concentration in proeutectoid ferrite during austenitization in hypoeutectoid steel

Abstract

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