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

Abstract

A technology for manufacturing hot-rolled steel plate with superfine grains is disclosed. The said steel plate contains C (0.1-0.16 wt.%), Si (0.12-0.3 wt.%), Mn (0.45-0.65 wt.%), P (0-0.020 wt.%) and S (0-0.015 wt.%). Its technological steps include casing, heating to 1200-1230 deg.c, coarse rolling, and three-pass fine rolling. Its advantages are superfine crystal grain (3-6 microns), excellentproperties and simple chemical components.

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 ...

Examples

Embodiment

[0013] Embodiment: the production method of the hot-rolled steel plate with ultra-fine crystal grain is that carbon steel, especially the carbon steel with low carbon and low manganese content, is poured into 200 * (800~1200) * 5500mm continuous casting method with conventional continuous casting method Casting slabs, the continuous casting slabs are heated to 1200-1230°C in the heating furnace, and the heated continuous casting slabs are sent to Roll on the 1450mm hot rolling mill. Rough rolling adopts eight-pass rolling, and the rolling temperature is 950-1100°C. After the rough rolling, the intermediate slab enters the finish rolling mill for finish rolling, and the temperature at the entrance of the finish rolling mill is controlled to be 870-900°C. Finish rolling adopts six rolling passes, the reduction of the first pass of finish rolling is 13-16mm, the reduction of the second pass of finish rolling is 8-10mm, and the reduction of the third pass is 5-7mm , through the ...

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 ...

Examples

Embodiment

[0013] Embodiment: the production method of the hot-rolled steel plate with ultra-fine crystal grain is that carbon steel, especially the carbon steel with low carbon and low manganese content, is poured into 200 * (800~1200) * 5500mm continuous casting method with conventional continuous casting method Casting slabs, the continuous casting slabs are heated to 1200-1230°C in the heating furnace, and the heated continuous casting slabs are sent to Roll on the 1450mm hot rolling mill. Rough rolling adopts eight-pass rolling, and the rolling temperature is 950-1100°C. After the rough rolling, the intermediate slab enters the finish rolling mill for finish rolling, and the temperature at the entrance of the finish rolling mill is controlled to be 870-900°C. Finish rolling adopts six rolling passes, the reduction of the first pass of finish rolling is 13-16mm, the reduction of the second pass of finish rolling is 8-10mm, and the reduction of the third pass is 5-7mm , through the ...

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