TiC dispersion strengthening complex-phase steel bar and production method thereof

Abstract

The invention discloses a TiC dispersion strengthening complex-phase steel bar. The steel bar comprises the following chemical components of, in percentage by mass, 0.25%-0.30% of C, 0.60%-0.80% of Si, 1.30%-1.60% of Mn, 0.01%-0.15% of Nb+Ti, less than or equal to 0.045% of P, less than or equal to 0.045% of S, less than or equal to 0.005% of O, 0.005%-0.008% of N and the balance Fe and inevitableimpurities; the effective Ti content, namely the content of titanium after titanium oxide, titanium nitride and inclusions are removed from steel, is greater than or equal to 0.03%; and the steel barstructure is composed of ferrite, pearlite, bainite and a precipitated phase, and the precipitated phase is mainly fine dispersed TiC. A production method of the steel bar comprises the steps of smelting, continuous casting, rolling and temperature control cooling; and the continuous casting billet heating temperature is 1100 DEG C-1250 DEG C, the finish rolling temperature is 850 DEG C-950 DEG C, and the temperature on a cooling bed is 850 DEG C-900 DEG C.

Description

technical field [0001] The application relates to the field of iron and steel metallurgy and steel rolling, in particular to a TiC dispersion strengthened composite steel bar and a production method thereof. Background technique [0002] my country has a large amount of steel bars and a wide range of areas, but the strength level of my country's steel bar products is low, of which the 335-400MPa level accounts for more than 70%, and the performance is single. The use of low-grade steel bars not only increases the consumption of steel, but also increases the consumption of resources and energy, and aggravates the burden on the environment. With the continuous improvement of building safety and environmental protection requirements, the upgrading of steel bar products is imminent. [0003] Common methods to improve the strength level of steel products are as follows: 1) Strong water penetration process after rolling to obtain closed-loop martensitic structure and improve stre...

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Problems solved by technology

[0003] Common methods to improve the strength level of steel products are as follows: 1) Strong water penetration process after rolling to obtain closed-loop martensitic structure and improve strength, but the plasticity, timeliness and weldability are poor; 2) Ultra-fine grain steel bars, using Low-temperature high-reduction technology to obtain steel products with a grain size of 10 or more, which is characterized by low alloy cost but high requirements for rolling line equipment; 3) micro-alloying technology, using niobium-vanadium-titanium micro-alloying technology function, to obtain high strength, which is characterized by low requirements for rolling line equipment, but needs to add alloys, and the cost is high

For example, some domestic manufacturers use vanadium-nitrogen microalloying technology to obtain 600MPa-level ultra-high-strength anti-seismic steel bars. Patent No. 102851580 A discloses "HRB600E anti-seismic steel bar and its production method", and patent No. 101732787 A discloses "A 600MPa-level anti-seismic threaded steel bar and its manufacturing method” and so on; all obtain high strength and shock resistance by adding a large amount of vanadium-nitrogen alloy, the manufacturing cost is high, and it is very difficult to further increase the nitrogen content in molten steel, thus limiting the strengthening effect of vanadium element; at the same time, the existing Patents related to high-strength steel microalloying technology do not involve fine control of steel structure and strength correlation

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