NEW TECHNOLOGIES OF RADIAL FORGING OF PIPE ON A MANDREL IN HOT AND COLD CONDITION

Abstract

Based on the analysis of known and our own experience, the expediency of using radial forging to produce short pipes on a conical mandrel made of special steels in a hot state is shown. It is noted that producing pipes by radial forging on a mandrel in a hot state is of practical interest only in the production of pipes with a diameter of more than 200 mm with an average wall thickness and thick-walled. The experimental technology of radial forging of short pipes of heat-resistant alloys KhN45Yu and KhN38VT on a fixed conical mandrel, developed and implemented on the SKK-14 RKM, is described. The patented and practically implemented technology of cold radial forging of pipes from stainless steels on a mandrel without using a special mechanism for holding the mandrel with a drive for its movement is presented. The new technology, compared to the technology of the Austrian company GFM, does not require the manufacture of a sufficiently complex tool, devices, as well as a significant amount of time for its assembly, installation and subsequent dismantling, which significantly reduces productivity, especially when receiving limited batches of pipes. As a result of the experimental work carried out without the use of a special mechanism for holding the mandrel with a drive for its movement, which the RKM SKK-14 of GFM is equipped with, high-quality cold-formed pipes made of stainless steel 12X18H10T were obtained. A new technology for radial forging of long hollow sections with an internal conical surface and a special device developed for its implementation are presented. Working drawings of the device parts for radial forging of long hollow sections with an internal conical surface were developed, their manufacture was carried out, pilot tests were carried out, a pilot lot of finished hollow sections made of steel 20, 1300 mm long, with a conical internal surface with an angle of inclination of the inner wall of 0.07 degrees was received, which was delivered to the consumer.