HIGH-COAL SUSTAINABLE STEEL WITH EXCEPTED CHARACTERISTICS AND HIGH-FREE CHARACTERISTICS AND THEIR MANUFACTURING PROCEDURES

摘要

The invention provides a high-carbon steel pipe having superior cold workability and induction hardenability, and a method of producing the steel pipe. The method comprises the steps of heating or soaking a base steel pipe having a composition containing C: 0.3 to 0.8%, Si: not more than 2%, and Mn: not more than 3%, and then carrying out reducing rolling on the base steel pipe at least in the temperature range of (Ac1, transformation point -50° C.) to Ac1, transformation point with an accumulated reduction in diameter of not less than 30%. A structure in which the grain size of cementite is not greater than 1.0 mum is obtained, thus resulting in improved cold workability and induction hardenability.