550MPa grade large-thickness S550Q steel plate, and production method thereof

Abstract

The invention discloses a 550MPa grade large-thickness low-carbon bainite S550Q steel plate used for hydropower construction, and a production method thereof. The 550MPa grade large-thickness low-carbon bainite S550Q steel plate comprises, by mass, 0.14 to 0.17% of C, 0.20 to 0.40% of Si, 1.00 to 1.20% of Mn, 1.00 to 1.20% of Ni, P<=0.010%, S<=0.005%, 0.020 to 0.040% of Nb, 0.035 to 0.050% of V, 0.30 to 0.50% of Cr, 0.40 to 0.50% of Mo, 0.020 to 0.040% of Al in steel ingot preparation or 0.060 to 0.080% of Al in electro slag ingot preparation, and the balance Fe and inevitable impurities. The production method comprises steps such as heating, rolling, and heat treatment. The 550MPa grade large-thickness low-carbon bainite S550Q steel plate is high in purity, and excellent in mechanical properties; -20 DEG C and Z-direction section shrinkage of the parts at 1 / 4 thickness and 1 / 2 thickness are relatively high; the 550MPa grade large-thickness low-carbon bainite S550Q steel plate possesses excellent single bainite tissue, comprehensive performance, and welding performance.

Description

technical field [0001] The invention relates to a low-carbon bainite steel plate and a production method thereof, in particular to a 550MPa-level large-thickness S550Q steel plate and a production method thereof. Background technique [0002] In recent years, with the rapid development of hydropower construction, the demand for large-thickness steel plates has become increasingly prominent, and the market demand for steel for low-temperature pressure vessels with thick specifications is increasing. For a long time, due to the lack of necessary production equipment and technical support, and due to the poor mechanical properties of domestic steel with large thickness, large unit weight, and higher strength, such as negative temperature impact toughness, and high production costs, it cannot meet the needs of the domestic market. need. Large-thickness steel plates for hydropower often rely on forging, which seriously restricts the development of my country's hydropower station...

AI Technical Summary

Problems solved by technology

For a long time, due to the lack of necessary production equipment and technical support, and due to the poor mechanical properties of domestic steel with large thickness, large unit weight, and higher strength, such as negative temperature impact toughness, and high production costs, it cannot meet the needs of the domestic market. need

Large-thickness steel plates for hydropower often rely on forging, which seriously restricts the development of my country's hydropower station construction