TY - JOUR
T1 - Enhanced upper shelf energy by ultrafine elongated grain structures in 1100MPa high strength steel
AU - Jafari, M.
AU - Kimura, Y.
AU - Tsuzaki, K.
N1 - Funding Information:
This study was financially supported by JST , CREST . The Materials Manufacturing and Engineering Station at NIMS supported this work through the caliber rolling process. M.J. acknowledges NIMS for the provision of a NIMS Graduate Research Assistantship.
PY - 2012/1/15
Y1 - 2012/1/15
N2 - The ultrafine elongated grain (UFEG) structure with strong <1. 1. 0>//RD fiber deformation texture was produced by warm caliber-rolling at 500°C and final tempering at 550°C, namely tempforming in the 1100. MPa medium carbon-low alloy steel with ultralow phosphorus and sulfur concentrations. Charpy impact tests were performed at temperature range of -196°C to 150°C on the UFEG structure along with a conventional quenched and tempered (QT) structure. A remarkable increase in upper shelf energy of 150. J was obtained in the UFEG structure without delamination, while that of QT structure was 97. J. The UFEG structures tempered at higher temperatures of 625 and 700°C showed remarkable increase in Charpy absorbed energy from 150. J to 187. J and 203. J. Also, the QT structure absorbed almost same energy as UFEG structure at 700°C. The enhanced toughness was discussed with tensile ductility, void nucleation and growth, and their relations to microstructure including the <1. 1. 0>//RD fiber deformation texture.
AB - The ultrafine elongated grain (UFEG) structure with strong <1. 1. 0>//RD fiber deformation texture was produced by warm caliber-rolling at 500°C and final tempering at 550°C, namely tempforming in the 1100. MPa medium carbon-low alloy steel with ultralow phosphorus and sulfur concentrations. Charpy impact tests were performed at temperature range of -196°C to 150°C on the UFEG structure along with a conventional quenched and tempered (QT) structure. A remarkable increase in upper shelf energy of 150. J was obtained in the UFEG structure without delamination, while that of QT structure was 97. J. The UFEG structures tempered at higher temperatures of 625 and 700°C showed remarkable increase in Charpy absorbed energy from 150. J to 187. J and 203. J. Also, the QT structure absorbed almost same energy as UFEG structure at 700°C. The enhanced toughness was discussed with tensile ductility, void nucleation and growth, and their relations to microstructure including the <1. 1. 0>//RD fiber deformation texture.
UR - http://www.scopus.com/inward/record.url?scp=83855165647&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=83855165647&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2011.11.007
DO - 10.1016/j.msea.2011.11.007
M3 - Article
AN - SCOPUS:83855165647
SN - 0921-5093
VL - 532
SP - 420
EP - 429
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
ER -