High-toughness steel plate with yield strength at 460 MPa grade and production method thereof

Abstract

The invention discloses a high-toughness steel plate with yield strength at 460 MPa grade. The steel plate includes the following chemical components as raw materials by weight: 0.05-0.08% of C, 0.2-0.4% of Si, 1.2-1.6% of Mn, no more than 0.02% of P, no more than 0.01% of S, 0.04-0.06% of Nb, 0.04-0.07% of V, 0.006-0.012% of Ti, 0.0015-0.003% of Ca, 0.017-0.027% of Als and the balance of iron and impurities. The invention also discloses a production method of the high-toughness steel plate with yield strength at 460 MPa grade. The invention employs low-carbon design and appropriate controlled rolling and controlled cooling technologies to realize fine ferrite crystal grains, good toughness and good welding performance of the steel plate. The method has the advantages of simple process route, short production period, low manufacture cost and lax process system, and can be used for stable production on a wide and thick line.

Description

technical field [0001] The invention relates to the technical field of plate manufacturing, in particular to a high-toughness steel plate with a yield strength of 460 MPa and a production method thereof. Background technique [0002] Steel plates with a yield strength of 460 MPa are widely used in construction machinery such as coal machinery, lifting cranes, and trucks. Since construction machinery and trucks are often subject to large impact loads and are often used in cold environments, steel plates are required to have good toughness, especially low temperature toughness. When the steel plate is used, it is often cut into various shapes according to the design requirements, and then welded according to the needs when manufacturing the equipment. Therefore, the welding performance of the steel plate is very important. The welding performance determines the quality of the steel plate weldment and the welding speed. The welding speed directly affects the production of the p...

AI Technical Summary

Problems solved by technology

During continuous casting of slab, due to the peritectic reaction that occurs when molten steel solidifies, cracks are likely to occur on the surface of the slab, which will lead to cracks in the final steel plate and affect the surface quality of the steel plate; at the same time, the final rolling temperature of the steel plate is low, and the rolling mill Heavy load, prone to equipment safety accidents

In addition, the toughness of these existing steel plates is poor, and the impact energy at -40°C is only about 50J

Furthermore, the existing manufacturing process is complicated, and the normalizing heat treatment process is added on the basis of the controlled rolling + controlled cooling process, which leads to an increase in manufacturing costs and a longer production cycle; adding 0.15% to 0.40% of expensive metal Ni makes the alloy The higher the content, the higher the alloy cost of the steel plate

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