Abstract:
The invention relates to a groove contour of the substantially circularly grooved rolls of a reducing mill with three-high rolling stands, especially for rolling thick-walled tubes with a wall thickness/diameter ratio greater than 0.25. According to the invention, the groove contour of each roll (1) has a diameter enlargement (5) in the region of the groove base in which the material rolled in the roll discontinuity of the particular preceding groove in the roll direction can be formed.
Abstract:
A roll pass of a roll set having three rolls for a multi-stand mandrel-free stretch reducing mill has a roll pass shape that deviates from the circular. A tube is passed in its longitudinal direction through the non-circular roll pass shape enabling modification of a shape of a cross-section of the tube, so as to counteract the non-circular external diameter deviations of the tube. A final roll pass (finishing pass) of the stretch reducing mill is locally enlarged at peripheral points where the tube diameter of the entering tube would otherwise deviate downward from a target size and locally reduced in size at the peripheral points where the tube diameter would otherwise deviate upward from the target size.
Abstract:
In order to optimize the lubrication of a rolling rod in a process for hot-rolling metallic, elongate hollow bodies (21) by means of the rolling rod (2), which is arranged in the hollow body and to which lubricant is applied before the hot-rolling operation, the lubricant is applied to the rolling rod in solid form.
Abstract:
In order to optimize the lubrication of a rolling rod in a process for hot-rolling metallic, elongate hollow bodies (21) by means of the rolling rod (2), which is arranged in the hollow body and to which lubricant is applied before the hot-rolling operation, the lubricant is applied to the rolling rod in solid form.
Abstract:
A roll pass design for the sets of rolls of a non-mandrel type multiple-stand pipe reducing mill, each set of rolls having three rolls. In order to improve the roll pass design so that the flow of material in the pipe is acted upon locally in such a way that the occurrence of local thickening of the pipe wall at critical points along the circumference of the pipe during reduction is decreased, the magnitude of the curvature of the roll pass flanks of at least a plurality of sets of rolls succeeding one another in the rolling direction increases by constant amounts or by equal percentages.