Abstract
The quality of the macrostructure and surface of slabs with a cross section of 350 × 2600 mm from K60 steel was studied by the metallographic method. The quality of the macrostructure and surface of continuously cast slabs with a cross section of 350 × 2600 mm from steel of strength class K60 was studied by the metallographic method. The following internal defects have the highest degree of development: axial chemical inhomogeneity, axial looseness, cracks perpendicular to the faces of the workpiece. There are practically no axial cracks and point inhomogeneity. Increasing dependencies between different variants of the location of cracks perpendicular to the faces of the workpiece, as well as between nested and perpendicular cracks, have been established. An increasing dependence of the degree of development of cracks, perpendicular to the narrow edges of the workpiece, on the overheating of the poured metal above the liquidus temperature is revealed. To improve the quality of cast metal, it is recommended to cast steel with overheating not more, than 30 °C. The profile of cast slabs is characterized by the presence of a slight convexity of narrow edges in most billets. The surface quality of the investigated templates is satisfactory.
Keywords:
Pipe steel, continuous casting, slab, quality.