Investigation on the effect of reduction process on internal quality of high carbon steel billet and its evolution in as-rolled wire rod

The effect of reduction process, especially the reduction zone on the internal quality of continuous casting high carbon steel billets was studied by shifting active reduction rolls while at same casting condition, as well as identical reduction amount and gradient. In the present study, the heredity of the main internal defects emerged in billets with different reduction zones was also investigated after subsequent rolling process in terms of severity, regional distribution, and microstructure formation as well. For the investigated high carbon steel grade, the evolution of the internal quality in relation to the macrosegregation, internal crack and porosity illustrates the effectiveness and importance of applying mechanical reduction for the homogeneity improvement from the cast billet to the as-rolled wire rod product. Meanwhile, it is also suggested by the investigation the necessity of fine control for the implement of mechanical reduction process, or it may not have sufficient positive impact on homogeneity and compactness of billet and as-rolled product, but some other undesirable defects may even be induced by mechanical reduction.