Rimmed Steel

Rimmed steel, normally having a low carbon content (less than 0.15 %), have the evolved gases only partially killed or controlled by the addition of elements such like aluminium. The gases compose blowholes along the outer iron of the ingot – therefore the term rimmed. In general Blowholes are not objectionable unless they break through the outer skin of the ingot. Rimmed steels contain little or no piping, and have a ductile skin with good surface finish. The blowholes might break through the skin if they are not controlled correctly. Impurities and inclusion tend to segregate toward the centre of the ingot. Therefore, products made from this steel might be defective and should be inspected.