TUBE ROLLING METHOD WITH THERMOMECHANICAL TREATMENT Russian patent published in 2016 - IPC C21D8/10 B21C37/06 

FIELD: oil and gas industry.

SUBSTANCE: tube rolling method with thermomechanical treatment includes heating of tubular billet up to temperature of 1150-1300°C, piercing and further deforming with total radial deformation degree of at least 70%, at that radial deformation degree at each stage of deformation upon piercing shall not exceed 35%. Before the last stage of deformation the rough-edged tube with temperature of 700-880°C is subject to accelerated induction heating up to temperature of 850-1000°C, thereafter, not later than in 5 s, final deformation is carried out at sizing mill or tube-reducing machine and then cooled in the air.

EFFECT: improved application properties of the tube due to excluded structure with different grain-size, increased viscosity and plasticity of steel, improved strength properties of steel.

2 cl, 1 tbl