Technical gazette, Vol. 22 No. 1, 2015.
Original scientific paper
https://doi.org/10.17559/TV-20131003112325
The mechanics behind formation of secondary ledeburite during tool steel welding
Marica Prijanovič Tonkovič
; High Mechanical Engineering School, Šegova ulica 112, 8000 Novo mesto, Slovenia
Aleš Nagode
; University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva cesta 12, 1000 Ljubljana, Slovenia
Borut Kosec
; University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva cesta 12, 1000 Ljubljana, Slovenia
Ivan Samardžić
; J. J. Strossmayer University of Osijek, Mechanical Engineering Faculty in Slavonski Brod, Trg Ivane Brlić Mažuranić 2, 35000 Slavonski Brod, Croatia
Blaž Karpe
; University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva cesta 12, 1000 Ljubljana, Slovenia
Ladislav Kosec
; University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva cesta 12, 1000 Ljubljana, Slovenia
Abstract
In this article we describe the microstructural changes in the heat affected zone (HAZ) of the tool steel W. Nr. 1.2379, which was surfaced or welded by the submerged arc welding technique (SAW) with different welding parameters. Microstructure of the welds and of the surfacing welds was analysed by optical and scanning electron microscope. In this research, we particularly studied microstructural changes in the area of primary chromium carbides in the HAZ and their effect on the weld crystalization. We came to the conclusion that the temperature in the HAZ is high enough during the welding process that it caused primary carbides to dissolve and concentration of the carbide-forming elements and carbon increased in the surrounding austenite matrix area to eutectic composition, which remelts and solidified as secondary eutectic (ledeburite).
Keywords
carbides dissolution; crystallization; heat affected zone (HAZ); secondary ledeburite; submerged arc welding; weld
Hrčak ID:
135069
URI
Publication date:
23.2.2015.
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