A manufacturing method of the 2 phase stainless steel seamless steel tubes using the device sequence for seamless-steel-tubes manufacture, and it

摘要

It is a line of apparatus for making a high strength duplex stainless steel seamless steel pipe or tube for upper low temperature hardness oil wells and a related method. the apparatus line comprises a steel material heating device, a perforating and rolling device for forming hollow material, and a rolling device for forming a seamless steel pipe or tube of a prescribed shape by processing In the hollow material, there is a cooling device provided on the outlet side of the lamination device. This line of apparatus is used for drilling and rolling in heated steel material having a stainless steel composition and then processing it with the rolling device, after which, when the surface temperature of the The hollow part before cooling with the cooling device is treated as a cooling initiation temperature, cooling is performed at a cooling stop temperature of 600 ° c or more, with a temperature difference of at least 50 ° c from cooling initialization temperature at an average cooling rate of 1.0 ° c / s or more per external surface temperature.