Low-alloy and high-strength steel Q460C and production method thereof

Abstract

The invention discloses low-alloy and high-strength steel Q460C and a production method thereof. The steel comprises, by mass percent, 0.11%-0.15% of C, 0.20%-0.40% of Si, 1.30%-1.50% of Mn, 0.01%-0.02% of Nb, 0.050%-0.070% of Ti and 0.020%-0.040% of Als. The heating time of a plate blank is longer than or equal to 3.5 h, and temperature at the heating ending moment ranges from 1100 DEG C to 1190 DEGC; a CR manner is adopted for rolling, the temperature-holding thickness at the rolling starting moment is three times or more of the thickness of a finished steel plate, the accumulative reduction rate of finish rolling is larger than or equal to 66%, and the final rolling temperature ranges from 810 DEG C to 850 DEG C; and an ACC cooling manner is adopted, the finish cooling temperature of the steel plate ranges from 630-20 DEG C to 630+20 DEG C. According to the low-alloy and high-strength steel Q460C and the production method thereof, a low-Nb and high-Ti microalloy component system is adopted, toughness is not reduced on the premise that strength is ensured, temperature-control rolling and ACC cooling control processes are optimized, an ideal F+P structure is obtained, and the production cost is low.

Description

technical field [0001] The invention relates to a high-strength steel and a production method thereof, in particular to a low-alloy high-strength steel Q460C and a production method thereof. Background technique [0002] Q460C is a medium-to-high-strength steel grade, which is mainly used in construction machinery fields such as coal machinery hydraulic supports. At present, the market's demand for Q460C is mainly concentrated in medium plate products with a thickness specification of 12~16mm, accounting for more than 75% of the total demand for Q460C. According to the survey, many domestic steel mills have the ability to produce the relevant thickness specifications of this steel type, but these steel mills mainly adopt the composition design method of high Nb-high V-low Ti or high Nb-high V to ensure the quality of Q460C. Mechanical properties, that is: the Nb element in the steel is usually controlled within the range of 0.03wt% to 0.06wt%, the V element is controlled wi...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a low-alloy high-strength steel Q460C and its production method, while effectively ensuring that the mechanical properties of the finished product meet the requirements of GB / T1591-2009, and greatly reducing production costs; The technical problems of poor effectiveness of elemental cooling control and difficult control of smelting yield

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