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Centreline segregation occurs as a positive concentration of alloying elements in the mid-thickness region of continuously cast slab.Depending upon the severity of elemental segregation,variations in microstructure and non-metallic inclusions through the final product thickness will affect mechanical properties and potentially downstream processing such as weldability,particularly for high strength line pipe.Charpy impact tests were conducted API 5L grade X65 line pipe steel hot rolled from slabs with different levels of segregation,rated as Mannesmann 2.0 and 1.4.The results showed that centreline segregation does have an influence on the Charpy impact properties of line pipe steel.The segregation fraction in hot rolled stripsamples was in accordance with that assessed in the cast slabs and the segregated regions in hot rolled strip samples were found to be discontinuous.Charpy specimens located in segregated regions resulted in lower Charpy impact energy and exhibited linear features associated with microstructural features in the mid-thickness region of the rolled strip.The difference in recorded Charpy toughness can be considered minor and associated with the observed differences in pearlite structure at the centreline and level of MnS inclusions.