Correlation between microstructure and yield strength of a high-strength cold rolled enameling steel

Abstract

To develop strategies for modifying the enameling steel chemical composition and processing to minimize yield strength reduction during the enamel-fire anneal (EFA), the reasons for yield strength reduction of a high strength cold rolled enameling steel were studied by combining experiments and thermodynamic calculations. The yield strength reductions were evaluated from the primary strengthening mechanism using existing empirical relationships that relate microstructural parameters to yield strength. The results show that yield strength reductions resulted primarily from an increase in grain size and a decrease in dislocation density. The EFA appeared to have a negligible effect on the solubilities of Mn, Si, and P, and the solubilities are nearly equal to the bulk concentrations. On the other hand, the elements C and N are nearly completely tied up as precipitates in the form of cementite and AlN. Thus, they have a negligible contribution to solid solution strengthening. © Published under licence by IOP Publishing Ltd.