New technology and equipment of the small compact tube rolling plant (CTRP) has been developed for production of thick-walled hot-rolled tubes with the diameter 25 80mm from steels and alloys of different purposes and the relation of D/S 3 12. The produced tubes can be used as finished tubes and as tube stocks for the subsequent cold deformation.
The developed technology is realized in the equipment of the CTRP which includes the following rolling mills:
two-high screw-rolling piercing mill with guide nondriven disks and the individual drive of rolls;
two-high rotary elongator with guide nondriven disks and with the individual drive of working rolls;
two-high reducing-sizing screw-rolling mill with guide nondriven disks and the individual
drive of rolls;
block from 6-7 stands of longitudinal rolling of the type 3H-450.
The existing technological scheme and the equipment provide the production of high quality tubes with close tolerances on the wall thickness and the diameter :±5% and ±0.5% correspondingly and with the tube length up to 6m.
To increase technological possibilities the CTRP is equipped also with the sizing block with 6-7 stands of longitudinal rolling of the type 3H-450. The presence of this block permits to receive tubes of hexahedral or square profile besides the round ones.
The developed technological scheme is realized in two-high screw-rolling mills of the same type with guide nondriven disks. The rolling equipment of the mill-analogue "450-3" has been manufactured by JSC EZTM, power of the electromotors of the main drives is 1500kW. The annual output of such plant can be from 12000t up to 40000t of hot-rolled tubes depending on the range of products.
Tubes from different steels can be in the range of products of this plant. In the mill "450-3" of the "Krasny Octyabr" enterprise large lots of tubes from steels ШХ-15, 35, 40Х, 15ХН3А, 20Г, 30ГСА and etc. (Fig.1;2),Х18АГ12, from ferroaluminium,intinol, ЭП 836, ЭП 637, ДИ 38, Р6М5, and titanium and zirconium alloys were rolled besides the drill steel of grades 28ХГН3М, 55С2.