Microstructure, forming limit diagram, and strain distribution of pre-strained DP-IF steel tailor–welded blank for auto body application
In the present study, tailor-welded blanks (TWBs) of dissimilar material combination were fabricated by laser welding of interstitial-free (IF) and dual-phase (DP) steels using 2.4-kW power and 4 m/min scan speed. Subsequently, TWBs of asreceived sheet materials and IF steels were pre-strained up to...
| Authors: | , , , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2019 |
| Country: | México |
| Institution: | Universidad Autónoma de Zacatecas |
| Repository: | Repositorio Institucional Caxcán |
| Language: | English |
| OAI Identifier: | oai:http://ricaxcan.uaz.edu.mx:20.500.11845/2024 |
| Online Access: | http://ricaxcan.uaz.edu.mx/jspui/handle/20.500.11845/2024 |
| Access Level: | Open access |
| Keyword: | INGENIERIA Y TECNOLOGIA [7] Tailor-weldedblank(TWB) Pre-straining .Microstructure Forminglimit diagram(FLD) Strain distribution |
| Summary: | In the present study, tailor-welded blanks (TWBs) of dissimilar material combination were fabricated by laser welding of interstitial-free (IF) and dual-phase (DP) steels using 2.4-kW power and 4 m/min scan speed. Subsequently, TWBs of asreceived sheet materials and IF steels were pre-strained up to 20% major strain in the deformed specimens through an equibiaxial pre-straining setup. It was found that highly non-uniform strain distribution with nearly plane strain deformation mode was induced in the pre-strained TWBs, whereas an equi-biaxial strain was recorded for IF monolithic blank. Microhardness profiles and the effect of weld zone on the microstructural and mechanical properties of the as-received and pre-strained TWBs were studied. Further, the forming limit diagrams (ε-FLDs) of as-received TWB and IF steel were experimentally evaluated. The ε-FLD of pre-strained TWBs was experimentally determined, and ε-FLD of the pre-strained IF material was estimated using the Yld89 anisotropy plasticity model with the Hollomon hardening law. Subsequently, all these respective ε-FLDs were implemented as damage models in the FE simulations for predicting the limiting dome height (LDH) of as-received and pre-strained TWBs. It was observed that the error in LDH prediction of pre-strainedTWB domes was within 9.1% when the estimated ε-FLD of the pre-strained IF material was used as a damage model. The FE-predicted strain distributions and weld line movements of TWBs after the second stage of deformation were also successfully validated with the experimental data. |
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