Effect of Nb on Microstructural Evolution and Mechanical Properties of Hot‐Rolled Quenching and Partitioning Steels Containing Bainite

Abstract

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/srin.202100247.

Microstructure and Mechanical Properties of a Novel Ultra‐High Strength Hot‐Stamped Steel with High Hardenability

“…The development of automobile steel has focused on designing materials with high strength and good service performance to reduce the weight and improve crash performance for car body components. [1,2] Hot-stamped steels have earned widespread applications because they combine ultrahigh strength and good ductility, including A/B pillars, front bumper, side-impact beam, and rocker panel. [3][4][5] The hot-stamped parts finish the final stamping at the high temperature (%800 °C) stage and complete the transformation from austenite to martensite during the cooling process.…”

“…Before hot stamping, the steel sheet should be accurately punched according to the final part size and be pre-cold forming (deformation is about 90%) in the indirect hot stamping process. [1,2] However, the cold-rolled hot-stamped steel sheet exhibits hard and brittle properties due to work hardening, which brings difficulty to cut and pre-cold forming. Therefore, it is crucial to conduct an annealing process for the hot-stamped coldrolled sheet.…”