Comprehensive Metallographic Studies of the Netted Cracks Surface Defect

Abstract

The character of emerging surface defects is directly related to the technology of manufacturing metal products at each metal conversion. Star, netted, and transverse cracks are the defects that are the most significant and hardly removable in the continuous casting of steel in what considers the quality of surface. We applied optical and scanning electron microscopy to accurately determine the place of and reason for the emergence of netted cracks. The results obtained by metallographic examination of hot-rolled 140-mm round blank parts, continuously cast ingots, and "top crusts" of smaller and larger facets enabled us to determine that the sites were netted cracks emerging and excluding the adverse effects in casting metal that result in the occurrence of defects.

Formation and Deformation Mechanism of Mountain‐Like Surface Crack on the Hot‐Rolled Thick Plate of HSLA Steel

“…There are many types of surface cracks in hot-rolled thick plates, which can be classified according to their morphology and the location of appearance: transverse crack, longitudinal crack, corner crack, star crack, etc. [2][3][4][5][6] The formation causes of the cracks with different morphologies are different. Most types of hot-rolled plate cracks are associated with the surface defects of the continuous casting slab.…”