Study on Micro-inclusions Behavior of Beam Blanks

The type, magnitude, size and distribution of non-metallic inclusions in beam blanks were researched via systemic sampling and adopting metallographic analysis and SEM/EDS, and the origin of inclusions in H beam was analyzed through method of tracer.The result show that the average of T[O] is 70.8×10^-6, the volume ratio of micro-inclusions is 0.15%.Micro-inclusions mainly have three kinds: A, B and C, the total micro-inclusions contain 89.7% of A and B, the chemic elements of A and B are similar, the main difference of A and B is that they have different amount of Al, Ca.And C holds 10.3% in the micro inclusions, which has high content of S.The inclusions'size is mostly less than 10 μm.The distribution trait of inclusions in slab is mainly decided by them.