Micro-hardness variation of micro-phases during spheroidisation of AISI4340 steel

AISI4340 steel is the medium carbon low-alloy steel has got excellent prominence as a construction material. This steel is spheroidised on heating to the intercritical temperature range by different time intervals with the objective of increasing the number and fineness of the spheroids of cementite...

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Main Authors: Harisha S R, Sathyashankara Sharma, Achutha Kini U, Gurumurty B M, Ananda Hegde
Format: Article
Language:English
Published: Taylor & Francis Group 2021-01-01
Series:Cogent Engineering
Subjects:
Online Access:http://dx.doi.org/10.1080/23311916.2021.1875536
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author Harisha S R
Sathyashankara Sharma
Achutha Kini U
Gurumurty B M
Ananda Hegde
author_facet Harisha S R
Sathyashankara Sharma
Achutha Kini U
Gurumurty B M
Ananda Hegde
author_sort Harisha S R
collection DOAJ
description AISI4340 steel is the medium carbon low-alloy steel has got excellent prominence as a construction material. This steel is spheroidised on heating to the intercritical temperature range by different time intervals with the objective of increasing the number and fineness of the spheroids of cementite particles. A 9 hours, spheroidisation shows better spheroids of cementite particles. To study the effect of initial room temperature structure on spheroidisation primary heat treatments like normalising and hardening are carried out for as-bought steel. Tensile property (yield strength, ultimate tensile strength and percentage elongation), hardness (Rockwell C scale) and micro-structural features and micro-hardness of micro-phases (ferrite and cementite) are studied. A continuous reduction in the tensile strength, hardness and improvement in ductility, is observed with the increase in spheroidisation time is observed in all the spheroidisation paths. Also, increased spheroidisation time shows a lesser aspect ratio for spheroids. The micro-structure shows partial spheroidisation in all the conditions with more number of spheroids in normalised condition and finer size in hardened. Drastic reduction in strength and hardness values are observed in the hardened condition during spheroidisation.
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spelling doaj.art-0324eb72dc9c4943b0837aec25d00c812023-08-02T04:05:30ZengTaylor & Francis GroupCogent Engineering2331-19162021-01-018110.1080/23311916.2021.18755361875536Micro-hardness variation of micro-phases during spheroidisation of AISI4340 steelHarisha S R0Sathyashankara Sharma1Achutha Kini U2Gurumurty B M3Ananda Hegde4Manipal Institute of Technology, Manipal Academy of Higher EducationManipal Institute of Technology, Manipal Academy of Higher EducationManipal Institute of Technology, Manipal Academy of Higher EducationManipal Institute of Technology, Manipal Academy of Higher EducationManipal Institute of Technology, Manipal Academy of Higher EducationAISI4340 steel is the medium carbon low-alloy steel has got excellent prominence as a construction material. This steel is spheroidised on heating to the intercritical temperature range by different time intervals with the objective of increasing the number and fineness of the spheroids of cementite particles. A 9 hours, spheroidisation shows better spheroids of cementite particles. To study the effect of initial room temperature structure on spheroidisation primary heat treatments like normalising and hardening are carried out for as-bought steel. Tensile property (yield strength, ultimate tensile strength and percentage elongation), hardness (Rockwell C scale) and micro-structural features and micro-hardness of micro-phases (ferrite and cementite) are studied. A continuous reduction in the tensile strength, hardness and improvement in ductility, is observed with the increase in spheroidisation time is observed in all the spheroidisation paths. Also, increased spheroidisation time shows a lesser aspect ratio for spheroids. The micro-structure shows partial spheroidisation in all the conditions with more number of spheroids in normalised condition and finer size in hardened. Drastic reduction in strength and hardness values are observed in the hardened condition during spheroidisation.http://dx.doi.org/10.1080/23311916.2021.1875536aisi 4340 steelspheroidisationphase morphologyhardeningtensile strength
spellingShingle Harisha S R
Sathyashankara Sharma
Achutha Kini U
Gurumurty B M
Ananda Hegde
Micro-hardness variation of micro-phases during spheroidisation of AISI4340 steel
Cogent Engineering
aisi 4340 steel
spheroidisation
phase morphology
hardening
tensile strength
title Micro-hardness variation of micro-phases during spheroidisation of AISI4340 steel
title_full Micro-hardness variation of micro-phases during spheroidisation of AISI4340 steel
title_fullStr Micro-hardness variation of micro-phases during spheroidisation of AISI4340 steel
title_full_unstemmed Micro-hardness variation of micro-phases during spheroidisation of AISI4340 steel
title_short Micro-hardness variation of micro-phases during spheroidisation of AISI4340 steel
title_sort micro hardness variation of micro phases during spheroidisation of aisi4340 steel
topic aisi 4340 steel
spheroidisation
phase morphology
hardening
tensile strength
url http://dx.doi.org/10.1080/23311916.2021.1875536
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