Study on Indentation Response of Cold Rolled Strip Steel

The indentation response of cold rolled strip steel was studied to advance the understanding of surface scratch resistance by instrumented indentation technique. The effect of radial stress on indentation response was analyzed using numerical simulation and dimensional analysis method. It was revealed that the indentation plastic work of strip steel inlayed in epoxy resin remained unchanged roughly at the load of 200 mN, and the instrumented indentation hardness could be calculated with small error using a work approach. It was found that the reverse analysis algorithm proposed by Dao et al. (Acta Mater 49:3899–3918, 2001) for extracting elasto-plastic properties from indentation data was inapplicable to strip steel. The computation results showed that the indentation curvature \(C\) first decreased and then increased with the increase in radial tensile stress. And \(C\) first increased slowly and then rapidly with the increase in radial compressive stress. The turning point was about \(\sigma_{{{\text{add}}}} /\sigma_{{\text{r}}} = - 0.5\) in compression, and it would be \(\sigma_{{{\text{add}}}} /\sigma_{{\text{r}}} > 0.5\) in tension. The research results are valuable for controlling surface quality.