|About this Abstract
||MS&T23: Materials Science & Technology
||Advances in Understanding of Martensite in Steels II
||Substructure and Crystallographic Features of As-quenched Lath Martensitic Steels
||Akinobu Shibata, Goro Miyamoto, Shigekazu Morito, Akiko Nakamura, Taku Moronaga, Houichi Kitano, Ivan Gutierrez-Urrutia, Toru Hara, Kaneaki Tsuzaki
|On-Site Speaker (Planned)
The present study investigated the substructures and crystallographic features of as-quenched lath martensite (IF steel and 0.2C steel) using FIB-SEM serial sectioning and advanced transmission electron microscopy. A 3D analysis revealed that the morphology of the smallest structural unit exhibited a wedge-shaped plate instead of the ideal lath shape. The habit plane orientations were distributed from (5 7 5)A to (1 1 1)A in the IF steel, whereas they were near to that predicted based on the PTMC in the 0.2C steel. Moreover, the orientation changed significantly inside a given lath. The lath boundary consisted of regularly spaced steps with (0 1 1)M atomistic terrace planes, and the interfacial dislocations compensating for the misorientation between adjacent laths were observed on the lath boundaries. Additionally, carbon was segregated at the lath and block boundaries in the 0.2C steel. Our observation results indicated that the substructure changed significantly during quenching.