TY - JOUR
T1 - Effects of microstructure on inverse fracture occurring during drop-weight tear testing of high-toughness X70 pipeline steels
AU - Hwang, Byoungchul
AU - Kim, Yang Gon
AU - Lee, Sunghak
AU - Kim, Nack J.
AU - Yoo, Jang Yong
PY - 2005/2
Y1 - 2005/2
N2 - The effects of microstructure on inverse fracture occurring in the hammer-impacted region were analyzed after conducting a drop-weight tear test (DWTT) on high-toughness pipeline steels. Three kinds of steels were fabricated by varying the alloying elements, and their microstructures were varied by the rolling conditions. The pressed-notch (PN) or chevron-notch (CN) DWTT and Charpy V-notch (CVN) impact tests were conducted on the rolled steel specimens, and the results were discussed in comparison with the data obtained from CVN tests of prestrained specimens. In the hammer-impacted region of the DWTT specimens, abnormal inverse fracture having a cleavage fracture mode appeared, and the inverse fracture area correlated well with the upper-shelf energy (USE) obtained from the CVN test and with the grain size. The steel specimens having a higher USE or having coarse polygonal ferrite tended to have a larger inverse fracture area than those having a lower USE or having fine acicular ferrite. This was because steels having a higher impact absorption energy required higher energy for fracture initiation and propagation during the DWTT. These results were confirmed by the CVN data of prestrained steel specimens.
AB - The effects of microstructure on inverse fracture occurring in the hammer-impacted region were analyzed after conducting a drop-weight tear test (DWTT) on high-toughness pipeline steels. Three kinds of steels were fabricated by varying the alloying elements, and their microstructures were varied by the rolling conditions. The pressed-notch (PN) or chevron-notch (CN) DWTT and Charpy V-notch (CVN) impact tests were conducted on the rolled steel specimens, and the results were discussed in comparison with the data obtained from CVN tests of prestrained specimens. In the hammer-impacted region of the DWTT specimens, abnormal inverse fracture having a cleavage fracture mode appeared, and the inverse fracture area correlated well with the upper-shelf energy (USE) obtained from the CVN test and with the grain size. The steel specimens having a higher USE or having coarse polygonal ferrite tended to have a larger inverse fracture area than those having a lower USE or having fine acicular ferrite. This was because steels having a higher impact absorption energy required higher energy for fracture initiation and propagation during the DWTT. These results were confirmed by the CVN data of prestrained steel specimens.
UR - https://www.scopus.com/pages/publications/15044353990
U2 - 10.1007/s11661-005-0309-7
DO - 10.1007/s11661-005-0309-7
M3 - Article
AN - SCOPUS:15044353990
SN - 1073-5623
VL - 36 A
SP - 371
EP - 387
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
IS - 2
ER -