Middle Shelf During Ductile to Brittle Transition on Ferrite + Pearlite Structure Steel Sheet

Abstract:

The steels consisting of multi-phase structure show an advantage for their high strength and good formability. The ductile to brittle transition with decreasing temperature has been investigated by Charpy impact test with sub-size specimen for the ferrite + pearlite structure steel sheet. The transition curve of the absorbed energy showed a two-step transition behavior, and the “middle shelf” appeared clearly in the curve. The cleavage-like fracture with few dimples appeared on the fracture surface of the specimens at the middle shelf, and the plastic strain was detected just below the fracture surface. This result suggested that the fracture at the middle shelf propagates with the quasi-cleavage fracture accompanied with plastic deformation. Although the traces of fracture surface corresponded to (001), (011), and (112) bcc-iron planes, the (001) cleavage plane was not dominant for the fracture propagation path at the middle shelf.

• Periodical: Materials Science Forum (Volume 941)
• Pages: 453-457
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.941.453
• Online since: December 2018
• Authors: Hiroyuki Kawata*, Osamu Umezawa
• Keywords: Cleavage Fracture, Ductile to Brittle Transition, Quasi-Cleavage Fracture, Steel

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