Thick and heavy hot-rolled H-shaped steel capable of inhibiting grain growth and production method thereof

A technology for inhibiting grain growth and production methods, applied in temperature control, metal rolling, etc., to achieve the effect of inhibiting grain growth and enhancing effective regulation

Active Publication Date: 2021-02-26
MAANSHAN IRON & STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the composite precipitation of TiN and NbC is discussed, it mainly relies on the rolling "technical principle of strain-induced precipitation", which is significantly different from the present invention through composition design and continuous casting process control in principle and technology

Method used

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  • Thick and heavy hot-rolled H-shaped steel capable of inhibiting grain growth and production method thereof
  • Thick and heavy hot-rolled H-shaped steel capable of inhibiting grain growth and production method thereof
  • Thick and heavy hot-rolled H-shaped steel capable of inhibiting grain growth and production method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] For thick hot-rolled H-beams, it is difficult to control the austenite grain size during heating and cooling only by microalloying of Nb. Theory and experiments prove that TiN particles have high thermal stability and can effectively control the grain growth of austenite during heating and rough rolling. Therefore, it is necessary to adopt Ti / Nb composite microalloying. For thick hot-rolled H-beams, the addition of microalloying element Ti will form rectangular particles with edges and corners due to the coherent interface between TiN particles and the matrix, such as figure 1 shown. The edges and corners of such rectangular particles will have a large stress concentration, which will cause cracks in the continuous casting slab due to external stress and thermal stress during the cooling process of the continuous casting slab, resulting in the failure of Ti / Nb composite microalloying in the actual production process. technical challenge. Aiming at this technical prob...

Embodiment 2

[0053] A thick hot-rolled H-shaped steel that inhibits grain growth and its production method in this embodiment are basically the same as in Embodiment 1, except that it includes the following components in weight percentage: C: 0.05%; Si: 0.50%, Mn: 1.60%; Nb: 0.02%; Ti: 0.015%; N: 0.003%, and the balance is iron and other impurities. In this embodiment, the thickness of the flange of the finished hot-rolled H-shaped steel is 150mm.

[0054] A production method of thick hot-rolled H-shaped steel that suppresses grain growth in this embodiment, the basic process is consistent with that of Embodiment 1, the difference is that in this embodiment, the continuous casting slab is controlled during the continuous casting process. The cooling rate is 4.5°C / s, the volume fraction of TiN, NbC, and Ti+Nb composite particles precipitated inside the slab is 0.06%, and the average diameter of the corresponding second phase particles is 45nm.

[0055] When baking the submerged nozzle in t...

Embodiment 3

[0060] A thick hot-rolled H-shaped steel that inhibits grain growth and its production method in this embodiment are basically the same as in Embodiment 1, except that it includes the following components in weight percentage: C: 0.14%; Si: 0.31%, Mn: 1.32%; Nb: 0.032%; Ti: 0.011%; N: 0.004%, and the balance is iron and other impurities. In this embodiment, the thickness of the flange of the finished hot-rolled H-shaped steel is 100mm.

[0061] A production method of thick hot-rolled H-shaped steel that suppresses grain growth in this embodiment, the basic process is consistent with that of Embodiment 1, the difference is that in this embodiment, the continuous casting slab is controlled during the continuous casting process. The cooling rate is 3.9°C / s, the volume fraction of TiN, NbC, and Ti+Nb composite particles precipitated inside the slab is 0.052%, and the average diameter of the corresponding second phase particles is 40nm.

[0062] When baking the submerged nozzle in...

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Abstract

The invention discloses thick and heavy hot-rolled H-shaped steel capable of inhibiting grain growth and a production method thereof, and belongs to the technical field of iron and steel smelting. TheH-shaped steel comprises the following components in percentage by weight: 0.05%-0.20% of C, 0.10%-0.50% of Si, 0.80%-1.60% of Mn, 0.02%-0.04% of Nb, 0.008%-0.015% of Ti, 0.003%-0.005% of N, and thebalance of iron and other impurities. The production method of the thick and heavy hot-rolled H-shaped steel comprises the following production steps of molten steel smelting, casting blank continuouscasting, heating by a heating furnace, cogging mill rough rolling, universal mill finish rolling and cooling by a cooling bed, wherein the cooling speed of a continuous casting blank is controlled tobe smaller than 5 DEG C/s in the casting blank continuous casting process. In order to overcome the technical problem of Ti/Nb composite microalloying in the actual production process, the size and volume fraction of TiN second-phase particles are regulated and controlled by controlling the components of Ti and N; and epitaxial growth of the NbC-attached TiN particles is achieved through the optimized size and volume fraction of the TiN particles in cooperation with control over the cooling speed, and therefore it is guaranteed that the grain size of austenite obtained after final rough rolling is smaller than 50 micrometers.

Description

technical field [0001] The invention belongs to the technical field of iron and steel smelting, and more specifically relates to a thick hot-rolled H-shaped steel capable of suppressing grain growth and a production method thereof. Background technique [0002] With economic development and scientific and technological progress, hot-rolled H-shaped steel, one of the main structural steels, plays an important role in the construction of a series of large-scale engineering structures such as high-rise buildings, ocean platforms, large-scale all-weather railway traffic, and large bridges. However, at present, thick hot-rolled H-beam products with a high-performance flange thickness greater than 50 mm are still blank in China. Most of the heavy-duty H-beams are welded by thick plates, and the safety and convenience of the materials used are far inferior to those of hot-rolled H-beams. . The technical difficulty of high-performance thick hot-rolled H-beam lies in that due to ins...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/02C22C38/04C22C38/12C22C38/14B22D11/22C21D8/00B21B1/088B21B37/74
CPCB21B1/088B21B37/74B22D11/225C21D8/005C21D2211/001C21D2211/004C22C38/02C22C38/04C22C38/12C22C38/14
Inventor 邢军张建王永强吴保桥朱国辉夏勐汪杰黄琦吴湄庄彭林彦井成丁朝晖何军委陈辉
Owner MAANSHAN IRON & STEEL CO LTD
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