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http://dx.doi.org/10.3795/KSME-A.2015.39.5.543

Microstructural Realization of SD400 Rebar by Developing Tempcore Simulation Apparatus  

Park, Chun Su (R&D Center, Dongkuk Steel Mill Co., LTD.)
Yi, Hyang Jun (R&D Center, Dongkuk Steel Mill Co., LTD.)
Bae, Seh Wook (R&D Center, Dongkuk Steel Mill Co., LTD.)
Kim, Gil-Su (R&D Center, Dongkuk Steel Mill Co., LTD.)
Publication Information
Transactions of the Korean Society of Mechanical Engineers A / v.39, no.5, 2015 , pp. 543-547 More about this Journal
Abstract
The cooling process referred to as Tempcore has been applied to produce a high-strength rebar. Excellent rebar with strength and weldability can be manufactured from mild steel without the addition of alloying elements by using the Tempcore process. However, there are limitations to evaluating the effect of various chemical compositions and cooling conditions within a site facility. In this study, we developed an apparatus to simulate the Tempcore process and obtained microstructures with a hardened surface layer, an intermediate region and a soft inner core. The experimental apparatus has been equipped with a cooler set that is the same as the site facility and consists of a pump line that supplies pressure of 12-13 bar and flow rate of up to $50m^3/h$. In accordance with the simulation result of steel grade SD400 that requires more than 400 MPa of yield strength, both the hardened area ratio and the hardness with respect to each cooling depth were found to agree well with the product.
Keywords
Tempcore; Tempcore Simulation Apparatus; Hardened Layer; Hardened Area Ratio; Hardness; Microstructure; Rebar;
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