Direct quenching type yield 800mpa grade structural steel plate and production method thereof

Abstract

The invention discloses a direct quenching type yield 800 MPa level structure steel plate and a production method thereof. The steel plate comprises chemical components including, by mass percent, 0.05%-0.09% of C, 0.16%-0.20% of Si, 1.05%-1.15% of Mn, smaller than or equal to 0.01% of P, smaller than or equal to 0.003% of S, 0.015%-0.025% of Nb, 0.45%-0.55% of Cr, 0.3%-0.4% of Ni, 0.001%-0.0015%of B, 0.01%-0.02% of Ti, 0.02%-0.05% of Alt and the balance Fe and inevitable impurities. The production method comprises the procedures of smelting, continuous casting, heating, rolling, online direct quenching and tempering air cooling. The steel plate has the low carbon equivalent and welding crack sensitivity index and excellent low-temperature impact toughness and welding performance and canbe used in the fields such as hydropower stations, ships, ocean platforms and engineering machines.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a direct quenching type structural steel plate with a yield of 800MPa and a production method thereof. Background technique [0002] At present, structural parts such as construction machinery and hydropower stations have higher and higher requirements on the strength of steel. The traditional high-strength steel plate is quenched and tempered high-strength steel, which adopts off-line process. This method has long process flow, high energy consumption and high alloy content. Poor, at present there are also direct quenching + tempering process, but the alloy content is high, the cost is high and it is not conducive to weldability. [0003] The Chinese invention patent application with the publication number CN 108359879 A discloses a DQ-T method for a 1000MPa-grade steel plate for hydropower with a thickness of no more than 60mm. The DQ+T production process is adop...

AI Technical Summary

Problems solved by technology

[0002] At present, structural parts such as construction machinery and hydropower stations have higher and higher requirements on the strength of steel. The traditional high-strength steel plate is quenched and tempered high-strength steel, which adopts off-line process. This method has long process flow, high energy consumption and high alloy content. Poor, at present there are also direct quenching + tempering process, but the alloy content is high, the cost is high and it is not conducive to weldability

Images