Fewer stands longitudinal hot rolling minor diameter thin wall seamless steel tube rolling technique and equipment thereof

Abstract

The invention discloses the rolling technology of a fewer stander longitudinal hot rolling small diameter thin wall seamless steel tube which uses a heating furnace to heat a pierced billet to 950 DEG C to 1150 DEG C, a mandrel trolley pushes a mandrel into the heating pierced billet and is pushed to move forward, and the pierced billet is pushed into a wall reduction rolling unit that is formed by a plurality of wall reduction rolling mills to lead the pierced billet to be carried out longitudinal wall reduction rolling; the pierced billet that breaks away from the mandrel continues to be pushed into a stretch reducing rolling unit that is formed by a plurality of stretch reducing rolling mills to lead the pierced billet to be carried out longitudinal stretch reducing rolling until the rolling is finished; the pierced billet is put into a cold bed to cool; a straightening machine is used for straightening; a finished product is used for delivering and cutting; a flat head machine is used and a detecting machine is used for inspecting; a hydrostatic testing machine is used for detecting; the finished product is bundled and is put in storage. The invention uses the combination of the three-roll longitudinal rolling technology and a retained mandrel to adjust the straight roller longitudinal rolling with umbrella-shaped gears hydraulically and preciously to carries out diameter reduction and wall reduction rolling, and a rolled tube pipeline main control cabinet is used for operating stepless speed regulation of various stands so as to guarantee implementation of the technology, thus rolling the small diameter thin wall seamless steel tube with the diameter of Phi 12mm to Phi 76mm and wall thickness of 1mm to 6mm.

Description

technical field [0001] The invention belongs to the technical field of rolling equipment and rolling technology for steel pipes, and mainly relates to a rolling technology and equipment for longitudinally hot-rolling small-diameter thin-wall seamless steel pipes with few racks. It is especially suitable for the production of high-precision small-diameter thin-wall seamless steel pipes. Background technique [0002] Small-diameter thin-walled seamless steel pipes are widely used in various fields such as production and life. In 2007, 53% of the 16 million tons of steel pipes consumed in my country were small-diameter seamless steel pipes. At present, the overall equipment level of large and medium-diameter seamless steel pipe units in my country is relatively advanced, and the gap between production capacity and demand is not large; compared with that, the overall equipment level of small-diameter seamless steel pipe units is not high, and about 50% of the production capacity...

AI Technical Summary

Problems solved by technology

At present, in the actual rolling of small-diameter thin-walled seamless steel pipes, cold-drawing or cold-rolling methods are generally used to obtain small-diameter thin-walled seamless steel pipes. Several times of annealing, pickling, and phosphating, the production efficiency is relatively low

Moreover, the production of thin-walled seamless steel pipes has many processes, high cost, and waste of resources. There are problems such as slow efficacy, high energy consumption, low success rate, serious pollution, and high pressure on environmental protection.

Coupled with the anti-deformation force of the steel material itself, the range of raw material materials that can be processed by cold drawing (rolling) is quite narrow, which not only greatly wastes energy and resources, but also can only use multiple cold drawing to obtain higher precision for many materials. High small-diameter thin-walled seamless steel pipes are more labor-intensive and costly, and the existing technology is difficult to process small-diameter thin-walled seamless steel pipes with high precision, so the small-diameter thin-walled seamless steel pipes Processing is still a technical problem

Although some companies currently use three-roll cross-rolling technology for hot-rolled small-diameter thin-walled seamless steel pipes, but due to the constraints of the three-roll cross-rolling stress (three-way) deformation direction and the rigidity of the mandrel, in the skew rolling During the rolling process, it is easy to roll the thin-walled steel pipe into a triangle or twist shape

Therefore, there has been no substantial progress in the technology of three-roll cross-rolling of small-diameter thin-walled seamless steel pipes.

And the existing three-roll hot rolling equipment can only roll Φ76mm seamless steel pipe

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