355MPa-grade maritime work steel plate for polar region and preparation method of 355MPa-grade maritime work steel plate

Abstract

The invention discloses a 355MPa-grade maritime work steel plate for a polar region and a preparation method of the 355MPa-grade maritime work steel plate, and belongs to the technical field of microalloyed steel production, and the 355MPa-grade maritime work steel plate comprises the following components in percentage by mass: 0.06 to 0.014 percent of C, 0.20 to 0.50 percent of Si, 1.20 to 1.60 percent of Mn, 0.020 to 0.050 percent of Nb, 0.010 to 0.050 percent of Ti, 0.07 to 0.20 percent of Ni, 0.010 to 0.050 percent of Als, less than or equal to 0.025 percent of P and less than or equal to 0.020 percent of S. The preparation method of the steel plate comprises the steps of molten iron pretreatment, converter or electric furnace smelting, refining, continuous casting, casting blank cleaning and slow cooling. And heating the slowly cooled blank in a furnace, rolling, air-cooling the steel plate, and carrying out flaw detection to obtain the qualified steel plate. The microstructure of the obtained 355MPa-grade maritime work steel plate is ferrite and pearlite, grains are fine and uniform, the grain size is about 10 grades, the yield strength reaches 400-480MPa, the tensile strength reaches 480-530MPa, the percentage elongation after fracture reaches 25-35%, the impact energy at the temperature of-40 DEG C is larger than or equal to 160J, the impact energy at the temperature of-52 DEG C is larger than or equal to 100J, and the requirements of project construction such as oil and gas exploitation and ocean engineering in extremely cold areas for the performance of the steel plate are met.

Description

technical field [0001] The invention relates to the field of microalloyed steel, belongs to the technical field of polar steel plate production, and in particular relates to a 355MPa grade polar marine steel plate and a preparation method thereof. Background technique [0002] The Arctic region is rich in oil and gas resources, and it is only in the primary development stage. With the shrinking ice cap in the Arctic region and the tight supply of global oil and gas resources, countries have successively launched oil and gas exploration projects in the Arctic, and an international competition in Arctic oil and gas development has taken shape. Steel is the main material for platform construction, mining equipment and ancillary buildings. In order to adapt to the harsh natural environment in the Arctic (minimum temperature -50°C), extremely high requirements are placed on the mechanical properties (especially low-temperature impact toughness) of serving steel materials. [0003...

AI Technical Summary

Problems solved by technology

It is used to solve the practical problem that the steel plates used in the construction of projects such as oil and gas resource development in the arctic extremely cold area must ensure the strength and meet the excellent low temperature impact toughness.

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