HIGH-ALLOY SEAMLESS STEEL PIPE MANUFACTURING METHOD

摘要

Disclosed is a high-alloy seamless steel pipe manufacturing method, in which a high-alloy steel billet heated to a temperature range of 900 to 1250 °C is pierced and rolled by a piercer equipped with a main roll having a surface roughness (Rmax) adjusted to a range of 150 to 500 µm, so that it forms no fin. It is preferred that the ratio (or an opening (WG) of a guide roll to an opening (WR) of the main roll) is adjusted to a range of 1.10 to 1.20. It is also preferred that the difference (?P - ?R) between a half angle (?R) made by the exit face of the main roll and the pass line and a half angle (?P) made by the rolling face of the piercing plug and the pass line is adjusted to a range of 0 to 3.0 degrees.