Steel plate adapting to large-linear energy welding and manufacturing method thereof

Abstract

The invention provides a steel plate adapting to large-linear energy welding and a manufacturing method thereof. The steel plate comprises the following chemical components: 0.05-0.12wt% of C, 1.2-1.6wt% of Mn, 0.12-0.35wt% of Si, less than or equal to 0.015wt% of P, less than or equal to 0.006wt% of S, 0.015wt% of Al, 0.005-0.02wt% of Ti, 0.008-0.05wt% of Nb, 0.0001-0.006wt% of N, less than or equal to 0.5wt% of Ni, less than or equal to 0.5wt% of Mo, 0.001-0.004wt% of Ca, the balance Fe and unavoidable impurities, wherein the equivalent carbon content is 0.32-0.43. By carrying out morphogenetic control on inclusions in a billet and adopting a rolling technology of rolling and cooling control, the invention manufactures a steel plate adapting to the large-linear energy welding. The steelplate has favorable low-temperature toughness and excellent joint toughness especially after large-linear energy welding.

Description

technical field [0001] The invention relates to the field of iron and steel materials, in particular, the invention relates to a steel plate with high welding heat-affected zone toughness under large heat input welding conditions and a manufacturing method thereof. Background technique [0002] High-strength low-alloy steel plate is an important engineering material, which is widely used in industrial fields such as shipbuilding, offshore platforms, oil and gas pipelines, bridges, high-rise buildings, pressure vessels, and machinery manufacturing. Its performance indicators include mechanical performance requirements, There are also welding performance requirements, among which the welding performance, especially the toughness of the welding heat-affected zone (HAZ), has become an important indicator related to the safety of the component. However, after the welding thermal cycle, the coarsening of HAZ grains will lead to local low toughness of the steel. Since the toughness...

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Problems solved by technology

However, the heat input corresponding to this welding heat simulation process is only 40,000-60,00J / cm, which is not considered a large heat input, and the literature does not provide actual welding data, so it is impossible to evaluate the joint of steel under the high heat input welding condition toughness

[0011] CN200510023216.0 relates to a thick steel plate that can be welded with large heat input and its manufacturing method. It proposes to add rare earth elements and form rare earth oxides to obtain improved steel resistance Radial energy welding characteristics, but rare earth elements are active elements, and it is easy to cause nozzle blockage in the process of pouring steel, so there are many restrictions in practical applications

U.S. Patent 124759 and CN200710052132.9 provide a kind of large input energy welding high-strength ship plate steel, they all use boron, utilize wherein BN to pin the growth of austenite grain, but this method is harmful to the steel Boron content (5-15ppm) and nitrogen content are demanding, making production more difficult

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