Forming Limit Curve Determination of a DP-780 Steel Sheet

In the present work, the forming limit curve (FLC) of a 1.1 mm thick DP-780 steel sheet is evaluated. The full FLC determination involved tensile tests of planar samples with different notch geometries ? providing data in the tension-compression range ? and Nakajima tests with a 40 mm diameter hemis...

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Detalles Bibliográficos
Autores: Schwindt, Claudio Daniel, Stout, Mike, Iurman, Lucio, Signorelli, Javier Walter
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/40481
Acceso en línea:http://hdl.handle.net/11336/40481
Access Level:acceso abierto
Palabra clave:Dp Steel
Forming Limit Curve
Formability
Nakajima Test
Dic Technique
Descripción
Sumario:In the present work, the forming limit curve (FLC) of a 1.1 mm thick DP-780 steel sheet is evaluated. The full FLC determination involved tensile tests of planar samples with different notch geometries ? providing data in the tension-compression range ? and Nakajima tests with a 40 mm diameter hemispherical punch and different notch geometries, covering the full loading zone of the forming limit diagram. The proposed Nakajima tool geometry reduces the standard test dimensions (ISO 12004-2) by 60%. Results show that the reduced diameter Nakajima test, in the particular case of Dual-Phase steels, overestimates limit strains when compared to the tensile test. This observed difference is explained in terms of the presence of a strain gradient through the sheet thickness imposed by the 40 mm diameter Nakajima punch, leading to the conclusion that this reduced sample type is not suitable for FLC determination when the DP-780 steel sheet is more than a millimeter thick.