Production line for rolling hollow steel and rolling forming production method for hollow steel

Abstract

The invention discloses a production line for rolling hollow steel and a rolling forming production method for hollow steel. The production line comprises a heating furnace, a roughing rolling unit, an intermediate rolling unit, a precision rolling unit and a cold bed which are arranged in sequence in the rolling direction, wherein the roughing rolling unit, the intermediate rolling unit, and the precision rolling unit are respectively formed by a plurality of four-roller rolling machines arranged in a staggered manner; the four-roller rolling machines can form circular or hexagonal rolling holes; the included angle between every two adjacent rolling machines is 45 to 90 degrees; the forming method comprises the steps of heating, continuous rolling, cutting for scaling-off and cooling. According to the invention, the conventional composite rolling production line and production process for hollow steel are improved in the light of the deformation rule of metal, so that a set of multi-roll rolling (circular and hexagonal) hollow steel production line and production method is formed, the problem of easy occurrence of out-of-tolerance fracture surface dimensional precision, especially the problem of high out-of-roundness of core holes in the conventional method is eliminated from the pass-by-pass evolution theory of a rolled piece.

Description

technical field [0001] The invention belongs to the field of steel rolling, and relates to a production line for rolling hollow steel and a rolling forming production method thereof. Background technique [0002] Hollow steel is a section steel with a round hole in the center, also known as hollow brazing steel (referred to as brazing steel or brazing steel). Its cross-sectional shape is generally circular, regular hexagonal, etc., and the diameter of the round hole is about 5-16mm. It is mainly used to make drill rods for rock drilling and blasting engineering. [0003] Most of the existing hollow steel rolling is to carry out compound rolling at the same time after heating two different materials, and then separate and obtain the hollow steel finished product after synchronous cooling. The rolling process includes: billet sawing to length - billet drilling - billet core loading - heating - rolling - cooling - sawing to length - core pulling - straightening - collection an...

AI Technical Summary

Problems solved by technology

[0004] However, when the hollow steel composite material is stacked by the traditional two-roll pass rolling method, due to the different properties of the two materials, the metal flow law during the deformation process is also different. When the finished pass is rolled into a circle, the core material cannot obtain a relatively complete circle due to the difference in material properties. This leads to the fact that the middle hole of the hollow steel after core pulling is not circular, and the product has low dimensional accuracy and cannot be obtained. In addition, due to the difficulty in adjusting the pass pattern, the cost of production management remains high; and the production stability of this method is also poor, the yield rate is low, and the production efficiency is low, which makes the competition of enterprises Although the production enterprises have optimized and adjusted the existing two-roll pass rolling method many times, the above problems have not been fundamentally solved, and the goal of efficient and stable production has not been realized.

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