| 摘要 |
Disclosed is a method of manufacturing sheet steel for sour-resistant line pipe having excellent sour resistance that can withstand changes in heating temperature and plate thickness during hot rolling, since the temperature during hot rolling easily decreases when the billet heating temperature drops or the sheet steel is thin. The disclosed steel billets contain C, Si, Mn, Nb, and Ti, while Al, P, and N content is limited. The billets further contain Ca: 0.001-0.004%, there are limitations such that S: not more than 0.0008% and O: not more than 0.0030%, and the Ca, O, and S content meets the condition [Ca](1 - 124[O])/1.25[S] > 3.0. The billets are reheated to 1000-1250°C, and then rough milled, finish rolled, and subjected to accelerated cooling. The cooling start temperature (Tc) of the accelerated cooling and the ratio of C content and Mn content [C/Mn] meet the condition 4 ? Tc × [C/Mn] ? 32, the cooling rate of the accelerated cooling is 10-40°C/s, and the stop temperature is 200-500°C. |
