An Introduction to Advanced Hot-Formed Steel for Automobile

作者：Liu W J^*

来源：Acta Metallurgica Sinica (English Letters), 2014, 27(3): 373-382.

DOI：10.1007/s40195-014-0076-9

• Advanced hot-formed (AHF) steel
• Dynamic carbon partitioning
• Flash copper precipitation
• Bake toughening
• Hot stamping

A recently developed advanced. hot-formed (AHF) steel for automobile is introduced and three physical metallurgy concepts based on which the AHF steel was designed are reviewed, they are dynamic carbon partitioning (DCP), flash copper precipitation and bake toughening. AHF steel is an upgrade of the existing hot-formed steel especially suitable for making components with superior crashworthiness; it can be processed by regular hot stamping equipment and process. A kinetics model for DCP is expressed in detail, which can be used to calculate the volume fraction of retained austenite based on four materials and processing parameters. The flash copper precipitation used as an additional strengthening mechanism for AHF steel is also discussed and its ultrafast kinetics can be attributed to the enhancement of quenched-in vacancies on copper diffusion. Also, the bake toughening of AHF steel is addressed; the mechanism of which may be related to the elimination of the less stable block-like retained austenite.

• 出版日期2014-6
• 单位东北大学