Fracture Initiation Toughness of Materials with Locally Embrittled Region
| Autor: | Fumiyoshi Minami, Kunihiko Satoh, Masao Toyoda |
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| Rok vydání: | 1983 |
| Předmět: | |
| Zdroj: | Journal of the Society of Naval Architects of Japan. 1983:322-328 |
| ISSN: | 1884-2070 0514-8499 |
| DOI: | 10.2534/jjasnaoe1968.1983.322 |
| Popis: | Experimental study has been carried out on the electron beam welds of high strength steel with mechanical and metallurgical heterogeneity.The main attention of the present study is paid not only to the role of the locally embrittled region on the initiation behaviors of cleavage and fibrous cracks, but also to the fracture characteristics of EB-welds of high strength steel. Using specimens extracted from EB-welds of HT 80 steel, 3-point bending COD tests are conducted.Fracture toughness of EB-weld metal of HT 80 steel used is the same as that of base metal, with reference to cleavage fracture initiation. On the contrary, fracture toughness of grain coarsened HAZ of EB-welds used is extremely embrittled regardless of fracture mode.In the tests of specimens with mechanical and metallurgical heterogeneity along notch front, cleavage/fibrous crack initiates at first in the locally embrittled region, i. e. grain coarsened HAZ. Moreover, crack initiation toughness of those specimens are almostly the same as that of specimen whose notch is located in the grain coarsened HAZ. In the particular case that locally embrittled region is located in the vicinity of specimen surface, however, toughness measured for cleavage fracture initiation are considerably scattered, compared with the case that embrittled region is located in the middle of the thickness.Accordingly, for the purpose of fracture toughness evaluation for materials with locally embrittled region, it is important to take into account of the effects of embrittled region not only on the crack initiation, but also on the scattering of fracture toughness. |
| Databáze: | OpenAIRE |
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