Metallurgical and mechanical properties of failed railway screw coupling in screw part

Metallurgical and mechanical investigations were applied to investigate the failure of the screw in train screw coupling. The results showed that the steel of the screw parts is DIN 41Cr4 steel with ferrite-pearlite microstructure. This indicates that the steel did not have the proper heat treatment...

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Main Authors: Sabry.M. Abdel Aziz, F. Abdel Mouez, M.A. Morsy
Format: Article
Language:English
Published: Elsevier 2025-03-01
Series:Journal of Alloys and Metallurgical Systems
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2949917825000070
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author Sabry.M. Abdel Aziz
F. Abdel Mouez
M.A. Morsy
author_facet Sabry.M. Abdel Aziz
F. Abdel Mouez
M.A. Morsy
author_sort Sabry.M. Abdel Aziz
collection DOAJ
description Metallurgical and mechanical investigations were applied to investigate the failure of the screw in train screw coupling. The results showed that the steel of the screw parts is DIN 41Cr4 steel with ferrite-pearlite microstructure. This indicates that the steel did not have the proper heat treatment according to the UIC code (826, 3rd edition, 2004), which is hardening and tempering to give the best mechanical properties especially fatigue resistance. Moreover, SEM micrographs show that the initiation point of crack is at the sharp points of the thread root, these sharp points act as a stress raiser that initiates the crack and accelerates the fatigue failure. Proper hardening and tempering process was conducted; this gave tempered martensite microstructure with acceptable mechanical properties that agreed with UIC code 826. The tempered martensite structure has a high fatigue resistance than the ferrite-pearlite structure. Therefore, it is highly recommended to form the threads by rolling dies instead of machining. This will result in the formation of rounded thread roots instead of sharp thread roots. The rounded thread roots are expected to improve the fatigue resistance especially when it is always done after heat treatment processes.
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institution Kabale University
issn 2949-9178
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publishDate 2025-03-01
publisher Elsevier
record_format Article
series Journal of Alloys and Metallurgical Systems
spelling doaj-art-465e36ce616443639c7c9d885a6a3f992025-02-03T04:17:09ZengElsevierJournal of Alloys and Metallurgical Systems2949-91782025-03-019100157Metallurgical and mechanical properties of failed railway screw coupling in screw partSabry.M. Abdel Aziz0F. Abdel Mouez1M.A. Morsy2Faculty of Industry and Energy, East Port Said University of Technology, North Sinai 45632, Egypt; Corresponding author.Corrosion Control and Surface Protection Lab., CMRDI, Cairo, EgyptWelding and NDT Department, CMRDI, Cairo, EgyptMetallurgical and mechanical investigations were applied to investigate the failure of the screw in train screw coupling. The results showed that the steel of the screw parts is DIN 41Cr4 steel with ferrite-pearlite microstructure. This indicates that the steel did not have the proper heat treatment according to the UIC code (826, 3rd edition, 2004), which is hardening and tempering to give the best mechanical properties especially fatigue resistance. Moreover, SEM micrographs show that the initiation point of crack is at the sharp points of the thread root, these sharp points act as a stress raiser that initiates the crack and accelerates the fatigue failure. Proper hardening and tempering process was conducted; this gave tempered martensite microstructure with acceptable mechanical properties that agreed with UIC code 826. The tempered martensite structure has a high fatigue resistance than the ferrite-pearlite structure. Therefore, it is highly recommended to form the threads by rolling dies instead of machining. This will result in the formation of rounded thread roots instead of sharp thread roots. The rounded thread roots are expected to improve the fatigue resistance especially when it is always done after heat treatment processes.http://www.sciencedirect.com/science/article/pii/S2949917825000070Screw CouplingFracture surfaceFailure analysisChemical analysisMechanical propertiesMicrostructure
spellingShingle Sabry.M. Abdel Aziz
F. Abdel Mouez
M.A. Morsy
Metallurgical and mechanical properties of failed railway screw coupling in screw part
Journal of Alloys and Metallurgical Systems
Screw Coupling
Fracture surface
Failure analysis
Chemical analysis
Mechanical properties
Microstructure
title Metallurgical and mechanical properties of failed railway screw coupling in screw part
title_full Metallurgical and mechanical properties of failed railway screw coupling in screw part
title_fullStr Metallurgical and mechanical properties of failed railway screw coupling in screw part
title_full_unstemmed Metallurgical and mechanical properties of failed railway screw coupling in screw part
title_short Metallurgical and mechanical properties of failed railway screw coupling in screw part
title_sort metallurgical and mechanical properties of failed railway screw coupling in screw part
topic Screw Coupling
Fracture surface
Failure analysis
Chemical analysis
Mechanical properties
Microstructure
url http://www.sciencedirect.com/science/article/pii/S2949917825000070
work_keys_str_mv AT sabrymabdelaziz metallurgicalandmechanicalpropertiesoffailedrailwayscrewcouplinginscrewpart
AT fabdelmouez metallurgicalandmechanicalpropertiesoffailedrailwayscrewcouplinginscrewpart
AT mamorsy metallurgicalandmechanicalpropertiesoffailedrailwayscrewcouplinginscrewpart