STEEL MATERIAL WITH LITTLE ALUMINA CLUSTER

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PROBLEM TO BE SOLVED : To provide a steel material which does not cause sliver flaw of a thin sheet for car and house electric appliance, defective quality of a thick plate for structural use, a reduction in low temperature toughness of the wear resistant thick plate and has little surface flaw and inner defect such as UST defect at welded part of a steel pipe for oil well pipe, etc., by preventing the coarse alumina cluster causing a defective product from being formed inside the molten steel and on the surface of Ar bubble. SOLUTION : Rare earth metals (REM) of one or more elements of Ce, La, Pr or Nd, are added into the molten steel after deoxidizing with Al or Al-Si so that by mass%, the content of total REM is 0.1 to <1 ppm and the content of solid-solution REM is <10 ppm.