| 摘要 |
PURPOSE:To prepare the titled pipe by quenching before tempering the seamless pipe made of the special composition steel containing C, Si, Mn, P, S, O, sol.Al, Nb and V. CONSTITUTION:The seamless pipe is formed with the steel containing 0.05- 0.20% C, 0.1-1.0% Si, 0.5-2.0% Mn, 0.03% or less P, 0.006% or less S, 0.005% or less O, 0.01-0.07% sol.Al, 0.05-0.1% one or more elements of Nb and V and, if necessary, further one or more elements of 0.10-0.40% Cu, 0.05-0.20% Ni, 0.05-0.8% one or more elements of Cr and Mo and 0.0005-0.005% B. The pipe is quenched through its both inner and outer surfaces from a temperature of 900 deg.C or higher with the cooling water having a temperature of 100 deg.--50 deg.C. Subsequently, it is tempered at a temperature within the range of 550 deg.C-AC1. |
