Tehnički vjesnik, Vol. 32 No. 6, 2025.
Izvorni znanstveni članak
https://doi.org/10.17559/TV-20250611002736
Correlation between Microstructure and Hardness of a Flash Butt-Welded Rail Joint
Srđan Bulatović
orcid.org/0000-0001-7864-6766
; Institute for Materials Testing (IMS), 11000 Belgrade, Bulevar vojvode Mišića 43, Serbia
*
Zorica Kovačević
; Institute for Materials Testing (IMS), 11000 Belgrade, Bulevar vojvode Mišića 43, Serbia
Vujadin Aleksić
orcid.org/0000-0002-6987-3438
; Institute for Materials Testing (IMS), 11000 Belgrade, Bulevar vojvode Mišića 43, Serbia
Ivan Samardžić
; Mechanical Engineering Faculty, University of Slavonski Brod, 35000 Slavonski Brod, Trg I.B. Mažuranić 2, Croatia
* Dopisni autor.
Sažetak
In this paper, the results analysis of microstructure and hardness examination of pearlite rail steel type 260 and its welded joint are presented. The relationship between the microstructure and the local hardness in different zones of the Flash Butt Welding (FBW) weld was examined, and the correlation was interpreted in terms of the quality of the examined microstructure. The main microstructural variations in the FBW weld occur within the Heat Affected Zone (HAZ). The local decrease in hardness in the zone of intercritical HAZ is caused by spheroidization of cementite. For this reason, the measured hardness values changed when advancing from the centreline of the weld towards the base metal. When moving slightly from the centreline of the weld to the maximum value across the weld in the area 1-2 mm away from the centre of the weld, the hardness value increased sharply. At the visible extent of HAZ, where the pearlite is partially spheroidized, the hardness decreased to a minimum value. Moving away from the visible part of the ZUT, the hardness gradually increased, returning to the value of the hardness of the base metal. The purpose of this paper is to present the relationship between microstructure and hardness on the longitudinal section of a flash butt-welded rail joint and to indicate their inter relationship. It has been confirmed that the altered microstructure in the welded joint of the rail leads to a change in hardness in areas of reduced hardness.
Ključne riječi
cementite; ferrite; flash butt welding; hardness; microstructure
Hrčak ID:
337710
URI
Datum izdavanja:
31.10.2025.
Posjeta: 469 *