Alternative protective coatings for hot stamped automotive body parts

Abstract : Various coatings are currently available for press-hardened steels used for the automotive construction, mainly with the aim of providing good anticorrosive properties to the body components. In order to improve performance of the coated products in terms of hot formability, corrosion protection and suitability for subsequent manufacturing processes, steelmakers and car manufacturers investigated various alternative coating materials. Only a few solutions resulted in a serial production. The aim of this study is to proceed to a screening of the performance of current coating variants, to identify new concepts for alternative coating materials and assess their suitability for the hot stamping application. The present work is focused on the study of Zn-Mn alloy coatings. Various electroplating baths and electric parameters were studied in order to determine optimal deposition conditions for obtaining Zn-Mn alloys with high Mn contents. The deposits obtained on large-scale steel plates were characterized with regards to their crystallographic, microstructural and anticorrosive properties. The behavior of the coating materials during austenitizing treatment was studied after heat treatment to different temperatures and heating durations. A particular attention was given to the evolution of the composition, the interdiffusion phases formed as well as to the presence of oxidation and evaporation mechanisms at high temperature. At last, the forming properties of the alternative coating materials and their susceptibility for liquid metal embrittlement were assessed on the basis of direct hot stamping experiments
Document type :
Theses
File URL :
http://docnum.univ-lorraine.fr/ulprive/DDOC_T_2018_0083_CLOSE.pdf
Complete list of metadatas

https://hal.univ-lorraine.fr/tel-01920933
Contributor : Thèses Ul <>
Submitted on : Tuesday, November 13, 2018 - 3:22:24 PM
Last modification on : Wednesday, November 14, 2018 - 1:17:27 AM

Identifiers

  • HAL Id : tel-01920933, version 1

Citation

Damien Close. Alternative protective coatings for hot stamped automotive body parts. Material chemistry. Université de Lorraine, 2018. English. ⟨NNT : 2018LORR0083⟩. ⟨tel-01920933⟩

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