Rare earth weathering steel rich in alloying rare earth elements and manufacturing method of rare earth weathering steel

Abstract

The invention discloses rare earth weathering steel rich in alloying rare earth elements and a manufacturing method of the rare earth weathering steel. The rare earth elements are one or more of threeelements of Ce, La and Y, in terms of mass percentage wt%, the content of the alloying rare earth elements is controlled within 0.005 wt% to 0.045 wt% through the process of feeding rare earth wiresinto steelmaking, weathering steel with a yield strength level of more than 355 MPa and an atmospheric corrosion resistant performance [a 240-hour periodic infiltration test, the corrosion rate is less than or equal to 1.2 g/(m<2>*hr)] which is equivalent to Q355GNH in national standard 'weathering structural steel' GB/T4171-2008, good mechanical properties, cold formability and welding performance are achieved, and the rare earth weathering steel can be widely applied to steel structure projects of vehicles, container manufacturing and construction, bridges, tower and mast structures and thelike.

Description

technical field [0001] The invention relates to rare earth weathering steel technology, in particular to a rare earth weathering steel rich in alloyed rare earth elements and a manufacturing method thereof, wherein the rare earth elements are one or more of the three elements of cerium Ce, lanthanum La, and yttrium Y , in terms of mass percent wt%, the alloying rare earth element content is controlled at 0.005 to 0.045 through the steelmaking process of feeding rare earth wire, which can provide a yield strength level of 355 MPa or more, and atmospheric corrosion resistance (240 hours cycle Infiltration test, corrosion rate ≤ 1.2g / (m 2 *hr)) is a weathering steel equivalent to Q355GNH in the national standard "Weathering Structural Steel" GB / T4171-2008. It has excellent mechanical properties, cold forming properties, and welding properties. It can be widely used in vehicles, container manufacturing and construction, bridges, towers Mast structure and other steel structure eng...

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Problems solved by technology

The invention requires P ≤ 0.005, rough smelting is very difficult, and converter blowing has very high requirements for P removal, that is, ultra-low P smelting technology and equipment are required, and the refining outside the furnace is strictly controlled to increase P, and the smelting cost is significantly increased; in addition, the steel of the invention It belongs to the category of high-strength low-alloy steel. Generally, W is not added. W is a precious alloy element. Adding W to the steel will significantly increase the alloy cost; in addition, the content of rare earth elements is low, only 0.0010-0.0041, which enhances corrosion resistance. limited role

Therefore, there are many improvements in the composition design of this invention. The too strict P content requirement increases the difficulty of smelting and the increase in process cost is very significant.

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