High strength boat deck with low-temperature strain aging brittleness resistant property and production method thereof

Abstract

The invention provides a high strength boat deck with a low-temperature strain aging brittleness resistant property and a production method thereof. The steel comprises the following chemical components in percentage by weight: 0.04% to 0.08% of C, 0.15% to 0.45% of Si, 0.8% to 1.2% of Mn, 0.005% to 0.15% of P, not more than 0.005% of S, 0.02% to 0.08% of Al, and not more than 0.005% of N, and also comprises at least two components selected from the following components in percentage by weight: 0.05% to 0.50% of Cu, 0.05% to 0.40% of Ni, 0.02% to 0.10% of V, 0.005% to 0.05% of Nb, 0.005% to 0.05% of Ti, and 0.0005% to 0.006% of Ca. The deck base heating temperature is 1100 to 1150 DEG C, the rolling temperature in the recrystallization area is 1050 to 1100 DEG C, the finishing temperature is 880 to 940 DEG C, the accumulated deformation is not less than 60%, then the deck base is cooled in the air until the temperature of the deck base reaches 810 to 840 DEG C and then is rolled in the recrystallization area, the finishing temperature is 780 to 820 DEG C, the accumulated deformation is larger than or equal to 50%; the deck base is subjected to a laminar cooling treatment after the rolling process, the cooling speed is 8 to 15 DEG C per second, and the re-reddening temperature is 550 to 640 DEG C. The obtained high strength steel is used to manufacture ship structure, has a low strain aging sensitivity index, and can be used in an extremely cold climate.

Description

technical field [0001] The invention belongs to the technical field of ultra-high-strength structural steel manufacturing, and relates to an ultra-high-strength low-temperature marine steel plate with excellent strain resistance and aging resistance and a manufacturing method thereof, including steelmaking and refining, continuous casting, rolling and cooling processes, used for Steel for ship or offshore platform structure under the condition of low temperature environment. Background technique [0002] After the steel plate is plastically deformed by cold working or reaches the specified plastic strain, the phenomenon that the strength and hardness increase and the plasticity and toughness decrease at room temperature or higher temperature is called strain aging. In the process of hull construction, steel plates are subjected to various forms of cold and hot bending, among which cold bending includes cold straightening, roll bending, molding, curling and hemming bending, e...

AI Technical Summary

Problems solved by technology

[0004] CN200610124380.5 discloses "a method for improving the low-temperature toughness and strain-aging low-temperature toughness of steel plates", which uses low-carbon and micro-alloy composition design combined with controlled rolling-controlled cooling technology to make the low-temperature toughness of hot-rolled steel plates only It meets the temperature requirement of -40°C, and the low-temperature toughness after strain aging can meet the temperature requirement of -20°C. This performance index cannot meet the use requirements of low-temperature marine steel below -60°C in extremely cold climates

Images