TY - JOUR
T1 - Correlation of microstructure and charpy impact properties in API X70 and X80 line-pipe steels
AU - Shin, Sang Yong
AU - Hwang, Byoungchul
AU - Lee, Sunghak
AU - Kim, Nack J.
AU - Ahn, Seong Soo
PY - 2007/6/15
Y1 - 2007/6/15
N2 - This study aims at correlating microstructure and Charpy impact properties in high-toughness API X70 and X80 line-pipe steels. Three kinds of steels were fabricated by varying alloying elements and hot rolling conditions, and their microstructures and Charpy impact properties were investigated. In addition, their effective grain sizes were characterized by the electron back-scatter diffraction (EBSD) analysis. The Charpy impact test results indicated that the steels rolled in the single phase region had the higher upper shelf energy (USE) than the steel rolled in the two phase region because their microstructures were composed of acicular ferrites. In the X80 steel rolled in the single phase region, the decreased energy transition temperature (ETT) could be explained by the decrease in the overall effective grain size due to the presence of acicular ferrite having smaller effective grain size. Thus, it had excellent mechanical properties in yield and tensile strengths, absorbed energy, and transition temperature, except in ductility.
AB - This study aims at correlating microstructure and Charpy impact properties in high-toughness API X70 and X80 line-pipe steels. Three kinds of steels were fabricated by varying alloying elements and hot rolling conditions, and their microstructures and Charpy impact properties were investigated. In addition, their effective grain sizes were characterized by the electron back-scatter diffraction (EBSD) analysis. The Charpy impact test results indicated that the steels rolled in the single phase region had the higher upper shelf energy (USE) than the steel rolled in the two phase region because their microstructures were composed of acicular ferrites. In the X80 steel rolled in the single phase region, the decreased energy transition temperature (ETT) could be explained by the decrease in the overall effective grain size due to the presence of acicular ferrite having smaller effective grain size. Thus, it had excellent mechanical properties in yield and tensile strengths, absorbed energy, and transition temperature, except in ductility.
KW - API X70 line-pipe steel
KW - Charpy impact test
KW - Effective grain size
KW - Energy transition temperature
UR - http://www.scopus.com/inward/record.url?scp=34147183709&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2006.12.097
DO - 10.1016/j.msea.2006.12.097
M3 - Article
AN - SCOPUS:34147183709
SN - 0921-5093
VL - 458
SP - 281
EP - 289
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
IS - 1-2
ER -