Method of producing steel products having excellent internal quality

Abstract

A method of producing a steel product having an excellent internal quality including subjecting a steel raw material of a round section to rolling at 3 or more passes to form a steel product of round section, wherein the rolling is conducted with a pair of upper and lower flat rolls at first pass, a pair of upper and lower same or different caliber rolls at second or more passes until just before a last pass, and a pair of upper and lower round caliber rolls at the last pass, under a condition that an area reduction in the first pass is within a range of less than a total area reduction from the raw material to the product.

1 - 2 . (canceled) 
     
     
         3 . A method of producing a steel product having an excellent internal quality comprising subjecting a steel raw material of a round section to rolling at 3 or more passes to form a steel product of round section, wherein the rolling is conducted with a pair of upper and lower flat rolls at first pass, a pair of upper and lower same or different caliber rolls at second or more passes until just before a last pass, and a pair of upper and lower round caliber rolls at the last pass, under a condition that an area reduction in the first pass is within a range of less than a total area reduction from the raw material to the product. 
     
     
         4 . The method according to  claim 3 , wherein the area reduction in the first pass is not less than 50% of a total area reduction in the second or more passes.