Original position statistic distribution analysis study of low alloy steel continuous casting billet

The homogeneity of low alloy steels continuous casting billet obtained under different technological conditions has been investigated by original position statistic distribution analysis technique. On the basis of systematic analysis of ten thousands primary optical signals at the corresponding original positions, the quantitative statistic distribution information of each element was obtained. The biggest degrees of segregation of low alloy steel continuous casting billet were calculated accurately according to the quantitative distribution maps of the contents. It was suggested that the weight ratio in a certain content range was used to judge the homogeneity of the materials, and the two models - the total weight ratio of contents (the degree of statistic homogeneity, H) within the permissive content range (C-0 +/- R) and the median value confidence extension ratio (the degree of statistic segregation, S) at 95% of confidence limit of weight ratio - were put forward. The two models reflect the composition and state distribution regularity of the metal materials in a large region. The difference between the sample with high columnar crystal and the sample with high equiaxed crystal has been studied by using the two models.