Micromechanical Aspects of Transgranular and Intergranular Failure Competition

0355778 - ÚFM 2011 RIV CH eng J - Journal Article
Dlouhý, Ivo - Tarafder, M. - Hadraba, Hynek
Micromechanical Aspects of Transgranular and Intergranular Failure Competition.
Key Engineering Materials. Roč. 465, - (2011), s. 399-402. ISSN 1013-9826
R&D Projects: GA ČR(CZ) GAP107/10/0361
Institutional research plan: CEZ:AV0Z20410507
Keywords : intergranular fracture * cleavage * fracture toughness
Subject RIV: JL - Materials Fatigue, Friction Mechanics

Quantification of characteristics that govern intergranular fracture initiation and propagation of this fracture micromechanism in competition with cleavage one is main aim of the paper. A NiCr steel of commercial quality and the same steel with an increased content of impurity elements, Sn and Sb, were used. Step cooling ageing was applied in order to induce intergranular embrittlement. Standard and pre-cracked Charpy type specimens were both tested in three-point bending to determine fracture toughness characteristics. In order to characterise the quantitative differences in fracture surfaces roughness a fractal analysis was applied. A boundary level of fractal dimension has been determined to be 1.12: fracture surface roughness with a higher value reflects high level of intergranular embrittlement and thus fracture resistance degradation.
Permanent Link: http://hdl.handle.net/11104/0194464