A Method for Reducing Bending of Mandrel Rod in Cold Rolling of Seamless Steel Tube

Abstract

The invention discloses a method for reducing bending of a seamless steel tube cold-rolled core rod. The method comprises the steps of material inspection, tool mold preparation, rolling preparation,rolling production and finished product inspection, continuous feeding, segmented positioning, sleeve compensation, counterweight containing, uniform rolling, one-by-one adding and two-end fixing areadopted, a front tube blank, a rear tube blank, a feeding chuck, a core rod chuck and an inlet chuck are adopted together to form a whole, through the containing of the core rod by the tube blank, thebending deformation faults of the slender core rod with the diameter 100 mm or below in rolling are eliminated from the source, on the basis of guaranteeing the rolling quality of the seamless steeltube, the field treatment consumption and the production cost are reduced, the labor intensity is reduced, and the consumption of the rolling mechanism and the tool mold of the rolling mechanism is reduced. The method is smooth and compact in working procedure, convenient to operate and maintain on site, safe, reliable, practical and efficient; the equipment investment is not increased, the cost is low, the expense is less, the on-site implementation is easy, the method has the advantages of eliminating the fault and reducing the cost and promoting the production effect, and the universality is strong.

Description

technical field [0001] The present invention relates to cold-rolling production equipment for producing seamless steel pipes in the metallurgical and mechanical industries, and more specifically relates to a method for reducing the bending of mandrel rods in the cold-rolling of seamless steel pipes, and is especially suitable for rolling large-size thick-walled pipes less than 1000mm slender mandrel. Background technique [0002] Seamless steel tubes are common iron and steel metallurgical products. The seamless steel pipe cold rolling mill is a widely used seamless steel pipe production equipment. The closed ring (countless diameters with different diameters) is formed by the deformation tool (pass) installed on the roll device and the plug installed at the end of the mandrel. Large to small continuous closed rings), metal deformation processing is carried out on the tube blank. Therefore, the working condition of the deformation tool composed of the ring hole type and th...

AI Technical Summary

Problems solved by technology

[0005] 1) The mandrel is easy to bend and deform: due to the small outer diameter of the mandrel, the part of the front half of the mandrel covered with the tube blank is more stable during rolling. The mandrel in the second half of the mandrel fed into the rear side of the chuck has poor stability, and there will be a large and continuous vibration under the action of the rolling force. With the displacement of the feeding chuck (the tube blank is gradually rolled), the The length of the second half of the mandrel of the tube blank is gradually increased, and the vibration amplitude is increased synchronously. Under such working conditions, the mandrel gradually bends and deforms, and once this phenomenon occurs, the deformation and bending will be accelerated

[0006] 2) Damage to deformation tools: After the mandrel is bent and deformed, it not only leads to an increase in the consumption of the mandrel, but also directly affects the structural damage of tools such as ring holes, plugs, roll devices, and imported chucks. The productive consumption of large-gauge thick-walled pipes becomes a bottleneck point in the production of this equipment

[0007] 3) Occupational harmful factors: When the mandrel is bent and deformed, harsh metal impact noise will occur during rolling, which will bring certain occupational hazards to the workers, and must be shut down in time for disposal, but the process of repairing and replacing the mandrel is cumbersome and requires Coordinated operations of multiple types of work, without mechanical construction equipment, all rely on the physical strength of the operators, and the labor intensity is high

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