To prevent a generation of defects on the inside surface without lowering productivity even when a seamless steel tube consisting of high carbon steel is manufactured.
This method is provided for manufacturing the high carbon steel seamless tube characterized by making the temperature of the billet heating to ≤1,200°C and an average strain rate AV in the axial direction which is determined by the equation (a) as ≤2.0 sec-1 when the seamless steel tube consisting of the high carbon steel containing, by mass, 0.95-1.10%C is pierce- rolled next to billet heating. AV=ln(A0/A)/(L/v)...(a), where, A is the cross-sectional area of a hollow tube stock after rolling. A0 is the cross-sectional area of the billet, L is the projected contact length of a material to be rolled with a piercer roll and v is piercing rate.
KITANI SHIGERU
Next Patent: BEARING FOR WORK ROLL OF ROLLING MILL