Reversible reciprocating periods hot milling roll

Abstract

The invention discloses a reversible repeated periodic hot rolling mill, which comprises a plurality of frames arranged along the movement direction of a rolling stock, and two pass rollers oppositely arranged on each frame, wherein the roller passes are arranged alternately between adjacent frames for staggering the compression directions of the rollers by 90 DEG C, each cross section of the pass has identical shape and consists of three arc segments, reversing mechanisms are arranged on both ends of the hot rolling mill for rotating the rolling stock by a certain angle after completing one travel rolling step, and a control mechanism is used for properly controlling the forward / reversal rotation of the pass rollers to achieve repeated periodic rolling of the rolling stock. The hot rolling mill achieves reversible repeated rolling and greatly improved rolling efficiency, and is particularly suitable for the production of extra-thick wall pipes and low-plasticity alloy steel pipes with difficulty in rolling without intermediate reheating, thus saving the energy resource greatly. The generation of pilger bell ends is obviated in the production, thus improving the rolling yield and achieving better economic benefit.

Description

1. Technical field: [0001] The invention belongs to the metallurgical industry, in particular to a hot rolling mill for manufacturing seamless steel pipes. 2. Background technology: [0002] Existing periodic hot-rolling mill for seamless steel tubes is a two-roller irreversible rolling mill, and the periodic rolls are engraved with a garden pass with variable cross-section, and there are mainly two main areas on its cross-section---empty rolling area and working area. The empty rolling area is equivalent to the "opening" of the roll. When it is opened, the capillary is turned over 90° and sent into the roll; the working area of ​​the pass is divided into three areas, see Figure 1: they are equivalent to the central angle θ 1 , θ 2 , and θ 3 , where θ 1 Known as the hammer head or front cone area, the radius of the hole pattern is gradually reduced, and it is used to compress the capillary to complete the main deformation of the capillary; θ 2 The area called the sizing ...

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Problems solved by technology

[0004] a. It is only suitable for the rolling of medium-thick-walled pipes. It is very difficult for the rolling of extra-thick-walled pipes, and it is also very difficult for high-alloy rolling with high deformation resistance.

[0005] b. Since the round hole has a side wall bevel of 25° to 30°, the deformation of the metal is uneven on the circumference of the hole. When the feeding amount is large, it is easy to produce transverse tension on the low plasticity alloy steel. crack

[0006] c. Since the rolling is cyclically fed and rolled, the amount of feeding each time is limited, generally no more than 30mm, so the production efficiency is low

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