Original scientific paper

https://doi.org/10.17559/TV-20150119110824

Effect of heat treatment on Charpy impact energy of microalloyed steel

Gorazd Kosec ; ACRONI d.o.o., C. B. Kidriča 44, 4270 Jesenice, Slovenia
Jelena Vojvodič Tuma ; Institute of Energetics, Mesarska 24, 1000 Ljubljana, Slovenia
Mirko Gojić ; University of Zagreb, Faculty of Metallurgy, Aleja narodnih heroja 3, 44103 Sisak, Croatia
Aleš Nagode ; University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva c. 12, 1000 Ljubljana, Slovenia
Antun Stoić ; J. J. Strossmayer University of Osijek, Mechanical Engineering Faculty in Slavonski Brod, Trg Ivane Brlić Mažuranić 2, 35000 Slavonski Brod, Croatia
Ivan Samardžić ; J. J. Strossmayer University of Osijek, Mechanical Engineering Faculty in Slavonski Brod, Trg Ivane Brlić Mažuranić 2, 35000 Slavonski Brod, Croatia
Borut Kosec ; University of Ljubljana, Faculty of Natural Sciences and Engineering, Aškerčeva c. 12, 1000 Ljubljana, Slovenia

Abstract

In this paper the microalloyed high-strength low-alloy (HSLA) Niomol 490K steel with an addition of niobium (0,032 wt. %) has been investigated. Heat treatment of the steel consisted of austenitisation at 1250 °C for 3 minutes and reheating up to 750 °C for 5 s. After austenitization the quenching was carried out in water with temperature of 70 °C and then in a lead bath up to 400 °C following cooling on the air. It was found that Charpy impact energy is higher and the transition temperature is lower for the transformation of austenite to bainite than to martensite microstructure. Experimental results showed that different fracture surface was observed. It is shown that preferred cleavage fracture occurred in the lattice plane (001) independently of steel microstructure.

Keywords

Charpy impact energy; Fracture surface; HSLA steel; Microstructure; Transition temperature

Hrčak ID:

160133

URI

https://hrcak.srce.hr/160133

Publication date:

19.6.2016.

Article data in other languages: croatian

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