A cold pilger rolling mill includes a pair of rolls rotatably attached to a roll stand, a crank drive on a driveshaft, which is rotatably mounted around a rotation axis, with a counterweight attached to the crank drive at a radial distance from the rotation axis, and a push rod with a first and a second end. The first end of the push rod is rotatably attached on the crank drive wherein, during the operation of the mill, a rotation of the crank drive is converted into a translation movement of the roll stand between a first and a second reversal position. The radial distance of the first end of the push rod from the rotation axis is adjustable, so that the distance between the two reversal positions of the translation movement of the roll stand is adjustable.

A gap control device for a Pilger die assembly of cold Pilger mills. The gap control device can independently control the height of a pair of bearing blocks which axially support an upper die. A lower plate has first and second receiving holes which respectively correspond to the upper portions of a pair of bearing blocks. First and second wedge plates are fitted into the receiving holes, and respectively have inclined surfaces on the upper portions thereof. First and second adjustment blocks respectively have inclined guide surfaces to be in surface contact with the inclined surfaces of the wedge plates, and are movable horizontally with respect to the lower plate. An upper plate is assembled to the upper portion of the lower plate to cover the adjustment blocks. First and second adjustment bolts allow the first and second adjustment blocks to be respectively manipulated in a horizontal direction.

Pilger rolling mill for working a hollow into a tube has a first roll stand mounted linearly moveable in a direction of motion. Translational motion of the roll stand causes rotational motion of the drive gear due to the cogging of the drive gear with the gear rack and, hence, also rotational motion of the roller arranged on the shaft of the drive gear and rotational motion of the other one of the two rollers in the opposite direction. Roll stand is connected with a crank drive and rotational motion of a motor drive is transformed into an oscillating translational motion of the roll stand by a connecting rod. Gear rack holder allows adjustment of the pilger rolling mill with respect to tube diameters of finished rolled tubes by arranging the first roll stand exchangeable by a second roll stand with a second dimension being different from the first dimension.

Cold pilger rolling mill for cold forming a hollow into a strain hardened tube with a roll stand with rollers mounted pivotably thereon. Efficient milling of long hollows is enabled without reducing the quality of the manufactured tubes. The cold pilger rolling mill has an unwinding device, wherein the unwinding device is arranged and in the feed direction of the hollow is located in front of the front mandrel thrust block such that at the unwinding device a spindle being rotatable around an axis being perpendicular to the feed direction of the hollow with the hollow wound thereon is receivable and in an operation of the cold pilger rolling mill the hollow is unwindable and feedable between the chuck of the front mandrel thrust block and the mandrel bar into the feed clamping sledge and the roll stand.

A process for producing a high-grade steel tube includes the steps of: providing a tubular blank of an austenitic high-grade steel, wherein the high-grade steel comprises in weight % no more than 0.02% carbon, no more than 1.0% manganese, no more than 0.03% phosphor, no more than 0.015% sulfur, no more than 0.8% silicon, no more than 17.5% t to 18.5% nickel, no more than 19.5% to 20.5% chromium, no more than 6.0% to 6.5% molybdenum, no more than 0.18% to 0.25% nitrogen, no more than 0.5% to 1.0% copper, and a remainder of iron and unavoidable impurities; and cold-forming the blank into a tube.

Cold pilger rolling mill for cold forming a hollow into a strain hardened tube with a roll stand with rollers mounted pivotably thereon. Efficient milling of long hollows is enabled without reducing the quality of the manufactured tubes. The cold pilger rolling mill has an unwinding device, wherein the unwinding device is arranged and in the feed direction of the hollow is located in front of the front mandrel thrust block such that at the unwinding device a spindle being rotatable around an axis being perpendicular to the feed direction of the hollow with the hollow wound thereon is receivable and in an operation of the cold pilger rolling mill the hollow is unwindable and feedable between the chuck of the front mandrel thrust block and the mandrel bar into the feed clamping sledge and the roll stand.

Pilger rolling mill for working a hollow into a tube has a first roll stand mounted linearly moveable in a direction of motion. Translational motion of the roll stand causes rotational motion of the drive gear due to the cogging of the drive gear with the gear rack and, hence, also rotational motion of the roller arranged on the shaft of the drive gear and rotational motion of the other one of the two rollers in the opposite direction. Roll stand is connected with a crank drive and rotational motion of a motor drive is transformed into an oscillating translational motion of the roll stand by a connecting rod. Gear rack holder allows adjustment of the pilger rolling mill with respect to tube diameters of finished rolled tubes by arranging the first roll stand exchangeable by a second roll stand with a second dimension being different from the first dimension.

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.

A process for producing a high-grade steel tube includes the steps of: providing a tubular blank of an austenitic high-grade steel, wherein the high-grade steel comprises in weight % no more than 0.02% carbon, no more than 1.0% manganese, no more than 0.03% phosphor, no more than 0.015% sulfur, no more than 0.8% silicon, no more than 17.5% t to 18.5% nickel, no more than 19.5% to 20.5% chromium, no more than 6.0% to 6.5% molybdenum, no more than 0.18% to 0.25% nitrogen, no more than 0.5% to 1.0% copper,and a remainder of iron and unavoidable impurities; and cold-forming the blank into a tube.