Method for mfg. hot rolled steel plate possessing superfine crystal grains and hot rolled steel plate produced

Abstract

The invention discloses a production method of a hot-rolled steel plate with ultra-fine grains and a hot-rolled steel plate produced therefrom. The hot-rolled steel plate adopts the chemical composition of low-carbon and low-manganese steel, and its weight percentage is: C: 0.10 to 0.16 %, Si: 0.12~0.30%, Mn: 0.45~0.65%, P: ≤0.020%, S: ≤0.015%; use conventional continuous casting method to pour it into continuous casting slab and heat it to 1200~1230℃ Carry out rough rolling and finishing rolling, control the entrance temperature of the finishing rolling mill to be 870~900°C, and the reductions in the first, second and third passes of finishing rolling are 13~16mm, 8~10mm and 5~7mm respectively, inducing Ultra-fine ferrite grains are produced, and the microstructure is ferrite and pearlite. The average grain size of ferrite is 3 to 6 μm. Ultra-fine grained hot-rolled steel plates have excellent comprehensive properties, and also have the advantage that the chemical composition of the steel is simple and easy to control.

Description

technical field [0001] The invention relates to a hot-rolled steel plate and a production method thereof, in particular to a production method of a hot-rolled steel plate with ultra-fine grains and the produced hot-rolled steel plate. Background technique [0002] Grain refinement of steel is the only method that can simultaneously improve strength and toughness. In recent years, countries around the world are constantly exploring methods of grain refinement. At present, the minimum ferrite grain size of carbon steel produced industrially on traditional hot rolling mills is 20 μm, and its tensile strength is 400 MPa. Countries such as South Korea and Japan have studied the method of refining the ferrite grain size of low-carbon manganese steel to 1 μm under laboratory conditions. Domestic steel mills have industrially produced ferrite and high-manganese steel components. Hot rolled steel plate with bainite structure. However, under the conditions of large-scale industrial ...

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Problems solved by technology

[0003] In order to overcome the deficiency that existing production technology cannot use carbon steel with low carbon and low manganese content to obtain ultra-fine-grained ferrite and pearlitic hot-rolled steel plates on traditional hot continuous rolling mills, the present invention provides a Production method of low-carbon low-manganese content carbon steel hot-rolled steel plate with ultra-fine-grained ferrite and pearlite structure and low-carbon low-manganese content carbon steel hot-rolled steel plate on traditional hot rolling mill

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