VN microalloyed steel for engineering machinery and manufacturing method thereof

Abstract

The invention belongs to the field of metal smelting steel, and particularly relates to VN microalloyed steel for engineering machinery and a manufacturing method thereof. The technical problem is solved by providing the VN microalloyed steel for the engineering machinery. The steel is subjected to VN microalloying by adopting a vanadium-nitrogen alloy. The manufacturing method comprises the following steps of desulfurizing molten iron, smelting in a converter, refining in an LF furnace, carrying out Ca treatment after RH vacuum refining, controlling the components of the molten steel according to the chemical components, carrying out continuous casting to obtain a plate blank, feeding the plate blank into a furnace, then heating, dephosphorizing, carrying out rough rolling, carrying out finish rolling, carrying out laminar cooling and coiling. The mechanical properties of a prepared steel plate meet the requirements that the tensile strength is 770MPa or above, the yield strength is 660MPa or above, the ductility is 15% or above, the ballistic work at the temperature of-20 DEG C is 200J or above, and a 180-degree cold bending test d=2a is qualified.

Description

Technical field [0001] The present invention belongs to the field of metal smelting steel, and specifically involves VN microalloying construction machinery steel and manufacturing methods. Background technique [0002] In recent years, my country's economy is booming, the scale of engineering construction, and basic construction, various modern large industrial facilities, modern large petroleum chemical, smelting, power station and high-rise buildings have increased year by year, for large tonnage crane demand It is also increasing. With the development of engineering machinery, more and more high-intensive structural steels need to be more and more high-intensive structural steels, which greatly promotes the development of steel steel steel. For construction machinery steel, it is necessary to have high yield strength, good cold forming performance, excellent impact resistance, etc., my country's steel industry has accelerated high-strength high-toughness engineering machinery...

AI Technical Summary

Problems solved by technology

[0006] Existing patents basically use TMCP or heat treatment to obtain high-strength construction machinery steel. Compared with the production cost of construction machinery steel prepared by heat treatment, the equipment requirements are higher, and the processing and forming performance of finished steel is lower than that of TMCP technology.

Moreover, most of the construction machinery steel produced by the existing TMCP technology adopts the microalloying route such as V-Ti-Nb-Mo-Cr, while the construction machinery steel produced by the VN microalloying route is rarely

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