A preparation process of high-strength marine steel

Abstract

The invention discloses a high strength shipbuilding section manufacturing technology, and belongs to the field of steel manufacturing. The manufacturing technological steps include: (1) rolling through a first cogging mill (BD1); (2) rolling through a second cogging mill (BD2); (3) rolling through two serial type roller mills; (4) composite cooling through air cooling and wind cooling; and (5) dissection and straightening of cooled initial materials. A cooling bed plant used in the step (4) comprises a cooling bed, a foundation trench, a ventilator and a forced cooling draught fan. Compared with the prior art, dissection is easy, cooling is rapid, cooling on the surface of flat-bulb steel is even, bending deformation is small, and the strength of a final product is large.

Description

technical field [0001] The invention relates to a steel production process, in particular to a high-strength marine section steel preparation process. Background technique [0002] With the rapid development of the shipbuilding industry in recent years, the bulb flat steel has gradually become the most important type of marine steel, and it is mainly used as the reinforcement of the ship plate, which is equivalent to the "rib" of a person. Bulb flat steel is composed of a flat web and a spherical ball head, and is an asymmetric steel. In the prior art, single rolling is commonly used, that is, it is directly pressed according to the load of the rolling mill and the elongation coefficient. The specific production process steps are steel billet→heating→single-line rolling→straightening. Due to the asymmetrical deformation of the single rolling process, the ratio of the web to the ball head is relatively large, and it is easy to cause bending after cooling on the cooling bed, ...

AI Technical Summary

Problems solved by technology

This process improves the deformation asymmetry in the single rolling process, but still has the following defects: ① Special roll pass design is required, as well as special pass patterns such as finished hole and finished front hole, and conventional steel billets and rolls cannot be used. The special machine is dedicated, the economic benefit is poor, and the specification is single; ②The technical requirement is one-time pressing, which is limited by the load and elongation coefficient of the rolling mill, so that it is impossible to produce large-sized rolled pieces. For super-sized bulbous flat steel, a single piece is still required Rolling; the thickness of the joint between two symmetrically rolled flat bulbs is relatively large, which brings difficulties to the subsection of the next process. Therefore, the hot cutting used in this case has an impact on the section structure and the final quality of the product. Defects; ④ For each specification of bulbous flat steel, a steel billet of a specification needs to be designed separately, which cannot realize the common use of billets

However, since the flat bulb steel needs to be cooled to a certain temperature in the production process, it can be straightened. If the cooling is not timely, the production speed will be forced to slow down and the production efficiency of the product will be limited.

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