Abstract

A high-strength steel tube bending die mandrel. The die mandrel is a straight rod-type mandrel and comprises a mandrel pull rod (4) and a mandrel body (1). The mandrel pull rod (4) is screwed to the rear end of the mandrel body (1). The shape of the cross section of the mandrel body (1) is adapted to the shape of a steel tube (5). The size of the cross section of the mandrel body (1) is less than the inner diameter of the steel tube (5). When the mandrel body (1) is in the steel tube (5), a unilateral gap between the mandrel body (1) and the steel tube wall is d, wherein 0

IPC Classes  ?

• B21D 9/04 - Bending tubes using mandrels or the like the mandrel being rigid

Abstract

An in-mold cooling shaft for a welding roll used in high-frequency pipe making. The in-mold cooling shaft is internally provided with a cooling water input flow channel leading to one end of the cooling shaft, and a cooling water output flow channel leading to the other end of the cooling shaft, wherein a water inlet of the cooling water input flow channel and a water outlet of the cooling water output flow channel are respectively located in respective corresponding end faces. Two end faces of the cooling shaft are provided with water pipe connecting nozzles, which are in communication with the water inlet of the cooling water input flow channel and the water outlet of the cooling water output flow channel, and a water outlet of the cooling water input flow channel and a water inlet of the cooling water output flow channel are both located in a side face of the cooling shaft. A welded pipe cooling device using the in-mold cooling shaft has the effect of cooling a welding roll mold and a bearing. Severe losses caused by high-temperature damage to the mold and shutdown can be avoided; and cooling water circulates in the mold, and as such, a molten weld pass can also be prevented from coming into contact with the cooling water during welding. Therefore, the toughness of the weld pass is improved, and the production quality is stabilized.

IPC Classes  ?

• B23K 13/00 - Welding by high-frequency current heating

Abstract

A high-frequency longitudinal welding apparatus for use in steel pipe production. The welding apparatus comprises a welding base (1), a pressing base (2), a high-frequency base (3), a guiding base (4), a sealing cover (5), a first gas supply pipe (6), and a second gas supply pipe (7). The welding base (1), the pressing base (2), the guiding base (4), the high-frequency base (3), the first gas supply pipe (6), and the second gas supply pipe (7) are located in the sealing cover (5). A steel pipe (8) passes through a through hole on a guiding base sealing board (58) of the sealing cover (5), then passes in succession through the guiding base (4), the high-frequency base (3), the pressing base (2), and the welding base (1), and passes through a welding base sealing board (56) of the sealing cover (5). The first gas supply pipe (6) passes through the guiding base sealing board (58) of the sealing cover (5), then extends to the side of the pressing base (2) away from the high-frequency base (3). The second gas supply pipe (7) passes through the guiding base sealing board (58) of the sealing cover (5), then extends to the side of the pressing base (2) near to the high-frequency base (3). In the layout design of gas supply pipes, gas protects the area above the weld seam not only before the welding but also after the welding, effectively solving the problem of integrated high-frequency welding. The overall sealing effect of the sealing cover (5) on welded segments causes argon not to be easily emitted, with inert gas protection during the welding process ensured under dual protection.

IPC Classes  ?

• B23K 13/06 - Welding by high-frequency current heating characterised by the shielding of the welding zone against influence of the surrounding atmosphere