High-property super-thick steel plate for 500 MPa-level engineering structure and manufacturing method thereof

Abstract

The invention belongs to the technical field of low alloy steels and production processes thereof, and particularly relates to a high-property super-thick steel plate for a 500 MPa-level engineering structure and a manufacturing method thereof. The high-property super-thick steel plate comprises the following components in percentage by weight: 0.020%-0.070% of C, 0.30%-0.60% of Si, 1.35%-1.60% of Mn, 0.010%-0.020% of P, S<=0.005%, 0.030%-0.060% of Nb, 0.010%-0.030% of Ti, 0.020%-0.050% of Als, 0.35%-0.45% of Cu, 0.20%-0.40% of Cr, 0.30%-0.60% of Ni, 0.05%-0.10% of Mo and the balance of Fe and inevitable impurities. In addition, the high-property super-thick steel plate disclosed by the invention meets the requirements that the welding cold cracking sensitivity coefficient Pcm is less than or equal to 0.20% and the ASTMG101-01 corrosion-resistant index I is more than 6.0. The manufacturing method disclosed by the invention adopts the low-C Cu-Ni-Cr-Mo-Nb-Ti component system, prevents the grain in an HAZ (Welding Heat Affected Zone) from being growingn because a grain refining effect achieved by compositely adding Nb-Ti is higher than the grain refining effect achieved by independently using V, enhances the obdurability of a steel plate base body and HAZ and is contributivee to enhancinge the welding line energy.

Description

technical field [0001] The invention belongs to the technical field of low-alloy steel and its production process, and in particular relates to a high-performance extra-thick steel plate for 500MPa-level engineering structures and a manufacturing method thereof. Background technique [0002] Large-scale engineering structures are developing towards all-welded structures and high parameters. The safety and reliability of structures put forward higher requirements for the strength, toughness, weldability, and seismic performance of steel. Therefore, material workers at home and abroad have proposed high-performance steel ( High Performance Steel) concept. High-performance steel refers to the steel with one or several properties of the material that have been significantly improved compared with traditional steel. substantial improvement. According to the classification of steel products in my country, medium and thick plates with a thickness greater than 60mm are generally c...

AI Technical Summary

Problems solved by technology

[0009] The steel plates recorded in the above three patent application documents have poor comprehensive properties, such as poor welding performance, high yield strength ratio, and insufficient weather resistance, and cannot meet the current actual needs for high-performance steel and extra-thick steel plates for engineering structures. Therefore, a A kind of high-performance steel extra-thick steel plate for engineering structure with good comprehensive performance, low process cost and short production cycle

Images