Rolling method of large size round steel

Abstract

The invention discloses a method for rolling large-sized round steel, which comprises the following steps: clamping the round casting blank by a manipulator and a foreplate with which the manipulator is provided; loading the casting blank in a roughing mill and turning the casting blank over every 1-3 passes of rolling for 7-11 reduction passes; then, loading the steel billet in a continuous mill and rolling for 2-6 reduction passes; wherein the pass schedule of the roughing mill is a box-box pass type; the pass schedule of the continuous mill is an ellipse-round-ellipse-round pass type; the continuous mill has an arrangement form alternating between horizontal and vertical arrangements; and the continuous mill allows a rectangular billet with the height smaller than 260mm and the width smaller than 280mm to enter. The method has saving passes and few rolling passes without tapping during the rolling process, therefore, the method has the advantages of high rolling efficiency, low rolling cost and saving energy, and more prominently, the quality of finished round steel is good.

Description

Technical field: [0001] The invention relates to a method for rolling medium and large-sized round steel by using a giant big round billet, in particular to a method for rolling medium-sized and large-sized round steel by using the cooperation of a blanking machine and a continuous rolling mill. Background technique: [0002] At present, the production of round steel generally has the following methods: [0003] 1. The general technology of round steel rolling is to turn different passes on the rolls and complete a series of axially staggered rolling on multiple racks. The general rolling pass system mainly includes "box-square-ellipse - Round" or "Box - Square - Hexagonal Square - Round" pass system. And the general rolling technology is rolled by a continuous rolling mill composed of multiple stands arranged in series. Due to the limitation of the strength of the stand, the maximum size of the large round steel rolled by the general continuous rolling mill is within Φ200m...

AI Technical Summary

Problems solved by technology

The disadvantages of rolling round steel with square billet or rectangular billet are: (1) The corners of square and rectangular billets are cooled quickly, and edge cracks are easily produced during rolling, especially when the carbon content and alloy content are high. Prominent; (2) The corners of square and rectangular billets are cooled quickly, and the pass wear is heavy during rolling, and the roll consumption is large; (3) The heating temperature is uneven, which affects the quality of finished steel

[0004] 2. In order to produce large-scale round steel, some manufacturers directly roll it on the blanking machine, and the specification can be rolled to Φ200mm or more. However, the efficiency of rolling with the blanking machine is very low, and it is easy to pour steel, and the rolling waste is much , unstable production

Greatly restricts the continuous production

[0005] 3. Some manufacturers use the old-fashioned horizontal rolling mill to produce it. Similarly, this method is also very low in production efficiency, and the flatness of the product is poor and the quality is unstable.

[0006] 4. Some manufacturers use the forging method to produce large round steel, and the forging production method is inefficient. In order to ensure the forging temperature, the forging has to be heated many times during production (that is, "heating-forging-reheating-reforging ”), and the surface quality and precision of forging are poor

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