Effect of Cr on high-temperature oxidation resistance of Cr–Si–Mn alloyed press-hardened steel during press hardening
Zhao Li, Zhisong Chai, Lingyu Wang, Zhou Wang, Qi Lü, Jeff Wang, Wei Xu
Abstract
It is of great interest to overcome the problem of high-temperature oxidation of press-hardened steels (PHS) in press hardening with a cost-effective Cr alloying strategy. Therefore, since Cr is one of the expensive metals, the effect of Cr (Cr ≤ 3 wt%) content on the oxidation resistance of Cr–Si–Mn alloyed steels was investigated. It was found that Cr–Si–Mn alloyed PHS with a Cr content of about 1.5 wt% or less cannot form a continuous Cr 2 O 3 layer during press hardening. However, when the Cr content reaches around 2.5 wt%, the PHS shows excellent oxidation resistance due to the formation of continuous Cr 2 O 3 and amorphous SiO 2 layers, as well as an Mn-rich oxide layer. However, further addition of 0.5 wt% could not significantly improve the oxidation resistance of this PHS. Moreover, the increase in Cr content simultaneously enhances the positive role of Si and Mn in high-temperature oxidation resistance. This work provides new insights into the design of the next generation of PHSs with economical and superior performance.