Titanium-reinforced low-cost Q390 grade hot rolled plate and production method thereof

Abstract

The invention discloses a titanium-reinforced low-cost Q390 grade hot rolled plate and a production method thereof. The chemical component percentages of the hot rolled plate are, by mass, 0.15%-0.18%of C, less than or equal to 0.10% of Si, 0.45%-0.50% of Mn, less than or equal to 0.015% of P, less than or equal to 0.06% of S, 0.015%-0.060% of Als, 0.040%-0.055% of Ti, less than or equal to 0.0050% of N, and the balance Fe and inevitable impurities; and the method includes steps of smelting, refining, continuous casting, heating a plate blank, controlling rolling, controlling cooling and rolling. By adopting a low-manganese and titanium micro-alloy strengthening design, the hot rolled plate has a yield strength greater than or equal to 390 MPa, a strength of extension greater than or equal to 490 MPa, an elongation greater than or equal to 20%, and a Ceq from 0.23 to 0.28, so that the hot rolled plate and the production method thereof have the advantages such as good welding performance, low content of alloy, good effect of galvanization and low cost.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a titanium-enhanced low-cost Q390 grade hot-rolled coil and a production method thereof. Background technique [0002] With the pressure of resources and environmental protection, it is imperative to reduce resource consumption and improve the performance of materials to achieve green production of steel. [0003] The existing Q390 grade high-strength structural steel adopts carbon-manganese alloying. The manganese element is usually more than 1.3%. The alloy consumption is high, resulting in waste of resources, and the carbon equivalent is ≥0.40. Preheating and postheating are required during the welding process to avoid welding. Defects increase welding difficulty and energy consumption. Moreover, structural steel is now mostly used for anti-corrosion and decoration such as galvanized, galvanized, etc. However, due to the high alloying elements of traditional ca...

AI Technical Summary

Problems solved by technology

[0003] The existing Q390 high-strength structural steel adopts carbon-manganese alloying, and the manganese element is usually more than 1.3%. The alloy consumption is high, resulting in waste of resources, and the carbon equivalent is ≥0.40. Preheating and postheating are required during the welding process to avoid welding Defects that increase welding difficulty and energy consumption

Moreover, structural steel is now mostly used for anti-corrosion and decoration such as galvanizing, galvanizing, etc. However, due to the high alloying elements of traditional carbon-manganese Q390 grade steel, defects such as missed plating and poor coating are prone to occur during hot-dip galvanizing. At the same time, Due to the high alloy content, it is prone to defects such as bending cracking and deformation difficulties

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