Method of manufacturing zirconium alloy tubular products containing (wt. %): niobium0.9-1.7; iron0.04-0.10; oxygen0.03-0.10; siliconless than 0.02, carbonless than 0.02, and zirconiumas the base of the alloy. This includes an ingot melting by multiple vacuum arc remelting, mechanical processing of the ingot, heating, hot working of the ingot, subsequent mechanical processing for the production of tubular billets, heat treatment of the tubular billets, application of a protective coating and heating to a hot pressing temperature, hot pressing, removal of the protective coating, multi-stage cold radial forging, vacuum thermal treatment, multiple cold rolling runs with a total deformation degree of 50-80-% per run and a tubular coefficient of Q=1.0-2.7 with intermediate vacuum thermal treatment after each cold rolling operation, and final vacuum thermal treatment of the resulting tubular products carried out at the final size with subsequent final finishing operations.

Method of manufacturing zirconium alloy tubular products containing (wt. %): niobium0.9-1.7; iron0.04-0.10; oxygen0.03-0.10; siliconless than 0.02, carbonless than 0.02, and zirconiumas the base of the alloy. This includes an ingot melting by multiple vacuum arc remelting, mechanical processing of the ingot, heating, hot working of the ingot, subsequent mechanical processing for the production of tubular billets, heat treatment of the tubular billets, application of a protective coating and heating to a hot pressing temperature, hot pressing, removal of the protective coating, multi-stage cold radial forging, vacuum thermal treatment, multiple cold rolling runs with a total deformation degree of 50-80-% per run and a tubular coefficient of Q=1.0-2.7 with intermediate vacuum thermal treatment after each cold rolling operation, and final vacuum thermal treatment of the resulting tubular products carried out at the final size with subsequent final finishing operations.

An apparatus and a process for forming an oval shaped duct, as well as a round duct for all required sizes and thicknesses for an AC system, in one continuous operation where two driving rolls advance a flat metal sheet to a multi-positioning bending roll, where the bending roll is moveable to a bending position for different curvatures and a non-bending position. The driving rolls advance the sheet through while the bending roll bends the sheet to form the curved sides, and the bending roll in the non-bending position form the flat sides of the oval shaped duct. A position sensor detects the position of the flat metal sheet in the rolls to control the location along the sheet where the bending roll is moved to either of the bending or non-bending positions while the driving rolls are stopped.

An apparatus and a process for forming an oval shaped duct, as well as a round duct for all required sizes and thicknesses for an AC system, in one continuous operation where two driving rolls advance a flat metal sheet to a multi-positioning bending roll, where the bending roll is moveable to a bending position for different curvatures and a non-bending position. The driving rolls advance the sheet through while the bending roll bends the sheet to form the curved sides, and the bending roll in the non-bending position form the flat sides of the oval shaped duct. A position sensor detects the position of the flat metal sheet in the rolls to control the location along the sheet where the bending roll is moved to either of the bending or non-bending positions while the driving rolls are stopped.

A cold pilger rolling mill for forming a tube shell to a tube includes a feed clamping carriage for receiving the tube shell and with a drive that is arranged to move the feed clamping carriage such that during the operation of the cold pilger rolling mill the tube shell moves step-by-step in the direction of the tool. A control and a sensor detect a measure of a force exerted during the operation of the cold pilger rolling mill by the tool onto the tube shell, and wherein the control is connected to the drive and the sensor. The control is arranged to regulate, during the operation of the cold pilger rolling mill, the step length per advance step with which the drive moves the feed clamping carriage to the tool as a function of the measure for the force, which measure is detected by the sensor.

A cold pilger rolling mill for forming a tube shell to a tube includes a feed clamping carriage for receiving the tube shell and with a drive that is arranged to move the feed clamping carriage such that during the operation of the cold pilger rolling mill the tube shell moves step-by-step in the direction of the tool. A control and a sensor detect a measure of a force exerted during the operation of the cold pilger rolling mill by the tool onto the tube shell, and wherein the control is connected to the drive and the sensor. The control is arranged to regulate, during the operation of the cold pilger rolling mill, the step length per advance step with which the drive moves the feed clamping carriage to the tool as a function of the measure for the force, which measure is detected by the sensor.

The state of the art discloses cold rolling mills comprising a roll stand, at least one roll rotatably mounted to the roll stand, a feed clamping saddle for feeding a blank, and a first drive for the feed clamping saddle. Those cold rolling mills have ball spindle drives with a high rate of wear as the drive for the feed clamping saddle. In comparison the object of the present invention is to provide a cold rolling mill whose drive for the feed clamping saddle involves no or only very slight wear and which in addition permits a slow movement of the feed clamping saddle. According to the invention that object is attained by a cold rolling mill which has a direct electromechanical linear drive for the feed clamping saddle.

The state of the art discloses cold rolling mills comprising a roll stand, at least one roll rotatably mounted to the roll stand, a feed clamping saddle for feeding a blank, and a first drive for the feed clamping saddle. Those cold rolling mills have ball spindle drives with a high rate of wear as the drive for the feed clamping saddle. In comparison the object of the present invention is to provide a cold rolling mill whose drive for the feed clamping saddle involves no or only very slight wear and which in addition permits a slow movement of the feed clamping saddle. According to the invention that object is attained by a cold rolling mill which has a direct electromechanical linear drive for the feed clamping saddle.

The seamless pipe in which a thin-walled portion in a pipe circumferential direction is formed in a pipe axial direction, in which a line segment formed by connecting one end and the other end of the thin-walled portion along a pipe surface with a shortest distance in a formation direction of the thin-walled portion is inclined at an angle of 5.0 or more with respect to the pipe axial direction. It is preferable that one end and the other end of the thin-walled portion are set from a region in a pipe selected with a shorter length between a length of 1.0 m in the pipe axial direction and 90% of a length in the pipe axial direction where the thin-walled portion turns once in the pipe circumferential direction.

An apparatus is disclosed having a plurality of cold rolling installations which each have a roll stand movable along a linear path and having at least one roll which is fixed rotatably to the roll stand, a drive connected to the roll stand and having an electric motor so adapted that the roll stand is drivable in an oscillating movement along the linear path, and a feed clamping saddle for feeding a blank. The apparatus has an electric control having at least two control outputs, wherein each control output is connected to the electric motor of the drive of a roll stand and wherein the control is so adapted that in operation of the apparatus it so controls the electric motors that they drive at least two of the roll stands with an adjustable phase displacement between the oscillating movements of the roll stands.