STEEL HAVING FINELY DISPERSED INCLUSIONS

摘要

An object of the invention is to provide a steel having good fatigue life characteristics and acoustic characteristics by eliminating the harmful effects of oxide based inclusions. The object is attained by the following steel. A steel having at least a part comprising: REM of which amount meets formula (1); and REM-containing inclusions of which number meets formula (2); wherein the concentration of A1203 in the REM-containing inclusions is 30 mass% or less (including 0%); Formula (1) ; -30 < REM (ppm) - (T.O (ppm)x 280/48) 0.8, wherein the inclusions of Formula (2) having an equivalent diameter of 1mum or more.