naa a22 4500 51082336X CHVBK 20180411083544.0 cr unu---uuuuu 180411e20131001xx s 000 0 eng 10.1007/s12541-013-0232-6 doi (NATIONALLICENCE)springer-10.1007/s12541-013-0232-6 A study to predict the creation of surface defects on material and suppress them in caliber rolling process [Elektronische Daten] [Doo-Hyun Na, Youngseog Lee] Finite element analysis coupled with a shear fracture model was carried out to predict the creation of surface defects on a material (AISI 4140 steel) and to reduce the surface defects in the caliber (or groove) rolling process, one of steel manufacturing processes. It was assumed that shear fracture owing to shear band localization in the material leads to onset of surface defects of the material during groove rolling. The shear fracture model used to simulate the crashworthiness of aluminum extrusions was applied to the groove rolling after the relation between shear stress ratio and equivalent plastic strain at fracture was modified. To validate the effectiveness of the proposed approach, a roll groove in an actual rod mill (SEAH BESTEEL Inc at Kunsan in Korea) was redesigned and field test was conducted as well. Results revealed that the surface defects on the material during groove rolling could be predicted by checking the number of elements that satisfied the shear fracture criterion. When the newly designed groove was used, finite element simulation of the 6-pass rolling sequence showed that the total number of the damaged elements was reduced from 796 to 629 by 21.0 %. Field test results showed that the total number of products that the surface defects was generated on the surface decreased from 405 to 259 by 36.0 % when the newly designed groove was used. Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg, 2013 Surface defects nationallicence Shear fracture model nationallicence Roll groove design nationallicence Caliber (Groove) rolling process nationallicence Finite element method nationallicence ω : a state variable that increases with plastic deformation nationallicence ɛ eq : equivalent plastic strain nationallicence ɛ eq ** : equivalent plastic strain at shear fracture nationallicence ɛ s + : equivalent plastic strain in equibiaxial tension nationallicence ɛ s − : equivalent plastic strain in equibiaxial compression nationallicence θ : shear stress ratio nationallicence θ + : shear stress parameter for equibiaxial tension nationallicence θ − : shear stress parameter for equibiaxial compression nationallicence ϕ : ratio of maximum shear stress and equivalent stress nationallicence k s : material parameter in shear fracture curve nationallicence η : stress triaxiality nationallicence σ eq : equivalent stress nationallicence τ max : maximum shear stress nationallicence σ 1 : maximum principle stress nationallicence σ 2 : middle principle stress nationallicence σ 3 : minimum principle stress nationallicence p : hydrostatic pressure nationallicence $\bar \sigma $ : equivalent stress nationallicence $\bar \varepsilon $ : equivalent strain nationallicence $\dot \bar \varepsilon $ : equivalent strain rate nationallicence C : equivalent carbon content nationallicence T : temperature in degrees Celsius nationallicence m : strain hardening exponent nationallicence n : strain hardening exponent nationallicence Na Doo-Hyun School of Mechanical Engineering, Chungang University, 221 Hukseok-Dong, Dongjak-Gu, 156-756, Seoul, South Korea aut Lee Youngseog School of Mechanical Engineering, Chungang University, 221 Hukseok-Dong, Dongjak-Gu, 156-756, Seoul, South Korea aut International Journal of Precision Engineering and Manufacturing Springer Berlin Heidelberg 14/10(2013-10-01), 1727-1734 2234-7593 14:10<1727 2013 14 12541 https://doi.org/10.1007/s12541-013-0232-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12541-013-0232-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Na Doo-Hyun School of Mechanical Engineering, Chungang University, 221 Hukseok-Dong, Dongjak-Gu, 156-756, Seoul, South Korea aut NATIONALLICENCE 700 1- Lee Youngseog School of Mechanical Engineering, Chungang University, 221 Hukseok-Dong, Dongjak-Gu, 156-756, Seoul, South Korea aut NATIONALLICENCE 773 0- International Journal of Precision Engineering and Manufacturing Springer Berlin Heidelberg 14/10(2013-10-01), 1727-1734 2234-7593 14:10<1727 2013 14 12541 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer