Wide and thick superfine-grain hot-rolled plate and method for producing same

Abstract

The invention discloses a generous specification ultra-fine grain hot rolling plate and its production methods. Its chemical composition (by weight percentage) is: C:0.12-0.18%,Si:0.12-0.25%,Mn: 0.70-1.30%,P:<=0.02%,S:<=0.015%, and Fe as the rest and inevitable impurities, plate thickness 8~14mm. In the invention through raising appropriately the mill inlet temperature, increasing the cooling capacity of the finishing mill , allocating the deflection of each finishing mill pass, to make it process in the non-recrystallization area of the austenite; rapid cooling after rolling and reeling at a low temperature, to obtain ultra-fined ferrite and multiphase of bainite, ferrite grain size3-6 mum, the mechanical properties of yield strength up to 400Mpa, over 520Mpa tensile strength, specific elongation over 28%. The invention can save alloy sources and bring great economic and social benefits for enterprises as there are no special steel alloy elements in the steel to substitute micro-alloyed steel with the same grade.

Description

technical field [0001] The invention relates to a hot continuous rolling steel plate and a production method thereof, in particular to a hot continuous rolling coil plate with wide and thick specifications and ultrafine grains and a production method thereof. Background technique [0002] At present, iron and steel materials are still the main body of engineering structural materials. However, with the rapid development of modern industry, the iron and steel industry is under increasing pressure to save resources, save energy, and protect the environment. Materials are required to be economical, environmentally friendly, and have superior performance. Higher requirements are put forward for the strength, service life and reliability of steel materials to meet the needs of light-weight energy-saving vehicles, long-span load-bearing bridges, high-rise buildings, large-scale construction machinery, deep well oil production pipes and Large-diameter oil (gas) pipelines, large-sc...

AI Technical Summary

Problems solved by technology

Now, researchers from the Rolling Technology and Continuous Rolling Automation Laboratory of Northeastern University and Baoshan Iron and Steel Group Corporation, Anshan Iron and Steel Group Corporation, Panzhihua Iron and Steel Group Corporation, and the General Iron and Steel Research Institute have formed a Q235 common carbon steel Composition-based, the production technology of hot-rolled steel sheets with ultra-fine grains that doubles the strength of thinner specifications (≤8mm), and hot-rolled coils with ultra-fine grains with wide and thick specifications (≥8mm), due to There are considerable difficulties in the limitation of the rolling capacity and coiling capacity of the rolling mill

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