|
Vol.42, No.9, 701 ~ 711, 2004
|
| Title |
| Analysis of Toughness and Transition Temperature of High-Toughness Pipeline Steels 2. DWTT Properties and Inverse Fracture Phenomenon |
| 황병철 Byoung Chul Hwang , 신상용 Sang Yong Shin , 이성학 Sung Hak Lee , 김낙준 Nack J. Kim , 안성수 Seong Soo Ahn |
|
|
|
| Abstract |
| In the present study, effects of microstructure on drop-weight tear test (DWTT) properties and inverse fracture occurring in the hammer-impacted region of high-toughness API X70 pipeline steels were investigated. Six kinds of steel specimens were fabricated by varying hot-rolling conditions. The DWTT was conducted on the rolled steel specimens, and the results were discussed in comparison with the Charily V-notch (CVN) impact test data. The DVVTT results indicated that all the specimens showed excellent DWTT properties as the percent shear area well exceeded 85%, irrespective of microstructures, although the inverse fracture occurred at test temperatures below -20℃. The specimens rolled in the single phase region had the lower 85% shear appearance transition temperature (SATT) than the specimens rolled in the two phase region, which was similar to the CVN test results. This 85% SATT had a good correlation with the energy transition temperature (ETT) obtained from CVN test. |
|
|
| Key Words |
| API X70 pipeline steel, Drop-weight tear test, Charpy V-notch, CVN, impact test, Inverse fracture |
|
|
 |
|
