Investigation on the deformation mechanism of alkali metal on inclusions in cord steel containing different aluminium content

The control and modification of non-metallic inclusions are crucial in enhancing the deformability and production efficiency of cord steel. This study investigated the effects of Na 2+ and K 2+ on the morphology, composition and deformability of inclusions in cord steel by adding Na 2 CO 3 and K 2 CO 3 . Scanning electron microscope equipped with energy-dispersive spectrometer and FactSage were applied to analyse the melting point and morphology of inclusions in ingots and forged samples. The results showed that the deformability of inclusions was improved and the melting point of inclusions decreased by adding Na 2 CO 3 and K 2 CO 3 . These inclusions were in the form of long strips after forging. Moreover, the deformability of inclusions in steel increased more obviously by adding Na 2 CO 3 than that with K 2 CO 3 . This study also found that the deformability of inclusions in sample with higher aluminium content was worse than that in sample with lower aluminium content. The inclusions can be deformed effectively under the condition of adding alkali metals into steel containing low aluminium content.