Abstract
The effect of the warm rolling process on the microstructure and the mechanical properties of low-carbon high-boron steels are studied in this work. To investigate these effects, boron-bearing low-carbon steel, subjected to roll at three different temperatures, was studied symmetrically and asymmetrically. The results of the experimental trials achieved by mechanical and microstructural analysis revealed that the use of warm rolling can represent a favorable method to suppress strain aging completely, and to eliminate the fluting effect and yield point elongation. In addition, the tensile and elongation properties are modified with the formation of boron nitride precipitates and dislocations in different thermomechanical conditions.
Highlights
The well-known phenomenon of the yield point in low-carbon steels arises from strain aging.The lock of dislocations through the interstitial atoms, i.e., carbon and nitrogen, causes the formation of a Cottrell atmosphere around the dislocation core, leading to a decrease in ductility and the formation of fluting lines in low-carbon steel sheets
Boron has been used as a carbide- and nitride-forming element to reduce strain aging through the extraction of interstitial atoms from solid solutions
It has been revealed that the addition of boron has an effective influence on decreasing the yield point elongation, which is the result of interstitial atom reduction in a solid solution [11,12]
Summary
The well-known phenomenon of the yield point in low-carbon steels arises from strain aging.The lock of dislocations through the interstitial atoms, i.e., carbon and nitrogen, causes the formation of a Cottrell atmosphere around the dislocation core, leading to a decrease in ductility and the formation of fluting lines in low-carbon steel sheets. The micro alloying elements (Al, Ti, Nb, V), via the formation of carbide and nitride precipitates, cause a decrease in the yield point elongation and an increase in ductility whenever fewer dislocations are pinned by a low amount of interstitial atoms [2,5,6,7]. Boron has been used as a carbide- and nitride-forming element to reduce strain aging through the extraction of interstitial atoms from solid solutions. Formation of boron nitride provides nucleation sites for Fe3 C and decreases dissolved carbon atoms in solid solution [8,9,10]. It has been revealed that the addition of boron has an effective influence on decreasing the yield point elongation, which is the result of interstitial atom reduction in a solid solution [11,12]. The reduction of dissolved C,N at grain boundaries and the change of carbide sites from a grain boundary to a ferrite matrix has a major role in the improvement of elongation in boron-bearing steels [10,11,13,14,15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
