The structural integrity of flash-butt welded premium rail steel – Evaluation of strength,microstructure and defects

Abstract

Experimental testing of flash-butt welded premium rail steel samples was undertaken to quantify the variation in strength through the cross-section of the weld, with results showing a general correlation between the width of the heat-affected-zone and the ultimate tensile strength. Microstructural examination and fractography revealed the presence of defects in some samples. Large defects can be identified by non-destructive testing methods as part of routine structural integrity assessment; however, small defects may escape detection but could propagate under cyclic loading in service leading to catastrophic failures. This work demonstrates the requirement for stringent control of heat input to prevent the development of defects in premium rail steels with high alloying content.

Keywords

Segregation flash-butt welding heat-affected-zone microstructure tensile strength

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References

Mansouri

Monshi

Microstructure and residual stress variations in weld zone of flash-butt welded railroads. Sci Technol Weld Join 2004; 9: 237–245.

Mutton

Cookson

Qiu

, et al. Microstructural characterisation of rolling contact fatigue damage in flashbutt welds. Wear 2016; 366–367: 368–377.

Ziemian

Sharma

Whaley

DE.

Effects of flashing and upset sequences on microstructure, hardness, and tensile properties of welded structural steel joints. Mater Des 2012; 33: 175–184.

Porcaro

Faria

Godefroid

, et al. Microstructure and mechanical properties of a flash butt welded pearlitic rail. J Mater Process Technol 2019; 270: 20–27.

Grigorenko

Kostin

Zhukov

, et al. Peculiarities of structural transformations in HAZ metal of rail steel M76 joint produced by flash-butt welding. J Phys Sci 2016; 6: 54–65.

Sun

Xuan

, et al. Microstructures and mechanical properties of flash butt welded high strength steel joints. Mater Des 2016; 96: 506–514.

Tawfik

Kirstein

Mutton

, et al. Verification of residual stresses in flash-butt-weld rails using neutron diffraction. Physica B Condens. Matter 2006; 385–386: 894–896.

Callister

Rethwisch

DG.

Materials science and engineering: an introduction. New York: Wiley, 2018.

Standards Australia International Ltd. Railway track material – part 20: welding of steel rail. AS 1085.20, 2012.

10.

Räsänen

Martikainen

Experimental review of metallurgical flash weld defects in welded joints: essence of flat-spots, penetrators and oxide inclusions. Sci Technol Weld Join 2011; 16: 471–476.

11.

Gerasin

Kalisz

Modeling of the Mn and S microsegregation during continuous casting of rail steel. Arch Foundry Eng 2015; 15: 35–38.

12.

Krauss

Solidification, segregation, and banding in carbon and alloy steels. Metall Mater Trans B 2003; 34: 781–792.

13.

Kuchuk-Yatsenko

Shvets

Didkovsky

, et al. Defects of joints of high-strength rails produced using flash-butt welding. Avtom Svarka 2013; 9: 3–9.

14.

Ichiyama

Kodama

Flash-butt welding of high strength steels. Nippon Steel Tech Rep 2007; 95: 81–87.

15.

Micenko

Muruganant

, et al. Double dip hardness profiles in rail weld heat affected zone – literature and review report. CRC for rail innovation, Brisbane, 2011.

16.

Bauer

Defects in and features of flash-butt welded joints. Weld Int 1988; 2: 836–841.

17.

Szablewski

Kalay

LoPresti

Development and evaluation of high performance rail steels for heavy haul operations. In: World Congress on Rail Research, Lille, 22–25 May 2011.

18.

Riecansky

Lucas

Formation and significance of weld-line defects in flash welded mild steel tube and bar. Weld Int 1974; 4: 1–27.

19.

Shaw

Experience with flashwelded rails in London transport service. Can Metall Q 1982; 21: 47–57.

20.

Klimowski

Papazoglou

Masubuchi

Analysis of manufacturing processes of large anchor chains. Cambridge, MA: Massachusetts Institute of Technology - Department of Ocean Engineering, 1983.