ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The enhancement of toughness at low temperatures in fine-grained low carbon steel wasstudied, basing on the theory of crack-tip shielding due to dislocations. Low carbon steel wassubjected to an accumulative roll bonding (ARB) process for grain refining. The grain sizeperpendicular to the normal direction was decreased to approximately 200nm after the ARB process.The fracture toughness of low carbon steel with the ARB process was measured at 77K by four-pointbending, comparing with the fracture toughness of those without the ARB. It was found that the valueof fracture toughness at 77K was increased by grain refining due to the ARB process, indicating thatthe ARB process enhances toughness at low temperatures and that the brittle-to-ductile transition(BDT) temperature shifted to a lower temperature. Quasi-two-dimensional simulations of dislocationdynamics, taking into account crack tip shielding due to dislocations, were performed to investigatethe effect of a dislocation source spacing along a crack front on the BDT. The simulation indicatesthat the BDT temperature is decreased by decreasing the dislocation source spacing
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.584-586.637.pdf
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