TMCP ocean structure thick plate and method for manufacturing same

Abstract

The invention provides a TMCP ocean structure thick plate and a method for manufacturing the same. The thick plate comprises the following chemical components: 0.015 to 0.18 weight percent of C, 0.5 to 2.0 weight percent of Mn, less than or equal to 0.6 weight percent of Si, less than or equal to 0.003 weight percent of S, less than or equal to 0.015 weight percent of P, 0.015 to 0.120 weight percent of Nb, 0.00 5 to 0.030 weight percent of Ti, less than or equal to 0.060 weight percent of Al, less than or equal to 0.010 weight percent of Ca, 0.003 to 0.010 weight percent of N, 0.001 to 0.006 weight percent of O, and the balance of Fe and inevitable impurities. The micro alloying design and TMCP rolling process control ensure the thick plate has a less than 120 J low-temperature impact toughness at a temperature of between 20 DEG C below zero and 40 DEG C below zero. Moreover, the thick plate has good welding performance and can be widely used for manufacturing D40 and E40 hull structures and ocean platforms.

Description

technical field [0001] The invention relates to the field of iron and steel materials, in particular, the invention relates to a thick plate for marine structures, and more specifically, the invention relates to a TMCP type thick plate for marine structures and a manufacturing method thereof. Background technique [0002] With the development of the shipbuilding industry, the requirements for the performance of ship plates are getting higher and higher. In addition to the increasing demand for steel plates with high strength, excellent toughness, weldability and high surface quality, the requirements for materials are also becoming more stringent. Classification societies of various countries have different technical requirements for ship plates, but the differences are not significant. According to the ship regulations of various countries' classification societies, ship plate steel is usually divided into general strength grades and high strength grades. General strength ...

AI Technical Summary

Problems solved by technology

[0014] 2. The publication number is JP 9279235A, and the Japanese patent publication titled "Manufacturing method of steel plate with excellent heat-affected zone toughness" discloses a method of magnesium oxide metallurgy to obtain a welded heat-affected zone. Tough thick plate, the alloy composition includes Mo, Ni, Cr and other elements, the cost is high

[0017] 5. The Japanese patent publication with the publication number JP 6240355A and the title of the invention is "Manufacturing Method of High Toughness TMCP Type Thick Steel Plate". , such as the amount of deformation and deformation temperature in the non-recrystallized region, resulting in reduced manufacturability and increased cost

[0018] 6. The publication number is JP 5295432A, and the Japanese patent publication titled "Manufacturing method of high-toughness and high-strength steel plate by online thermomechanical treatment", the steel plate does not use micro-alloy components, but the requirements on the TMCP process are too strict, for example, in The cooling rate is required to be greater than 20°C/s, which is difficult to achieve for steel plates with a thickness greater than 20mm on the thick plate rolling mill, which increases the difficulty of production, leads to reduced manufacturability and increased costs, and does not explain the toughness achieved Index value

[0019] 7. In the steel disclosed in the Japanese Patent Publication No. JP 62093346A a

Images