V-N microalloyed 550 MPa hot-rolled thick-wall H-shaped steel and production process thereof

Abstract

The invention relates to V-N microalloyed 550 MPa hot-rolled thick-wall H-shaped steel and a production process thereof, belongs to the technical field of building structural steel, and solves the problem that the use requirements for high strength (yield strength is greater than or equal to 550 MPa), high toughness (impact energy at -40 DEG C is greater than or equal to 150 J) and uniform section performance of the hot-rolled thick-wall H-shaped steel cannot be met in the prior art. The V-N microalloyed 550 MPa hot-rolled thick-wall H-shaped steel comprises the following chemical components including, by mass, 0.07%-0.13% of C, 0.20%-0.30% of Si, 1.35%-1.55% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.04%-0.07% of V, 0.005%-0.010% of Ti, 0.011%-0.022% of N and the balance Fe and inevitable impurities. Through the V-N microalloying effect, high strength and high toughness are guaranteed, and meanwhile the uniformity of the section performance of the thick-wall H-shaped steel is enhanced.

Description

technical field [0001] The invention relates to the technical field of building structural steel, in particular to a V-N microalloyed 550MPa hot-rolled thick-walled H-shaped steel and a production process thereof. Background technique [0002] In recent years, steel for construction steel structure has become a hot spot, and various national policies have brought convenience to the promotion and application of steel for steel structure. H-shaped steel is the most used steel in steel structure, accounting for more than 16% of the total steel used in steel structure. [0003] However, H-shaped steel is generally rolled by pass. Due to its structural characteristics, there are great differences in the deformation and cooling rate of the flange and web during the rolling process, especially the deformation of the joint between the flange and the web. Small, the cooling rate is small, the deformation of the web is large, and the cooling rate is large, which makes the section per...

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Problems solved by technology

[0003] However, H-shaped steel is generally rolled by pass. Due to its structural characteristics, there are great differences in the deformation and cooling rate of the flange and web during the rolling process, especially the deformation of the joint between the flange and the web. Small, the cooling rate is small, the deformation of the web is large, and the cooling rate is large, which makes the section performance of the H-shaped steel uneven. Usually, the strength of the flange is low, the strength of the web is high, and the strength difference is greater than 80MPa, and this difference increases with H The increase of steel specifications and the improvement of strength requirements become more and more obvious

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