Large heat input welding 670MPa-grade steel plate and manufacturing method thereof

Abstract

The invention discloses a large heat input welding 670MPa-grade steel plate. The large heat input welding 670MPa-grade steel plate comprises the following chemical elements in percentage by mass: 0.08%-0.12% of C, 0.80%-1.20% of Mn, 0.2%-0.6% of Cr, 1.5%-1.9% of Ni, 0.3%-0.5% of Mo, 0.1%-0.3% of Cu, 0.02%-0.05% of V, 0.001%-0.01% of Al, 0.006%-0.012% of Ti, 0.0008%-0.0014% of B, 0.001%-0.006% of N and the balance of Fe and other inevitable impurities. In addition, the invention also discloses a manufacturing method of the large heat input welding 670MPa-grade steel plate. The manufacturing method comprises the following steps: (1) smelting and casting; (2) rolling; and (3) quenching and tempering thermal treatment, wherein the quenching heating temperature is 900-980 DEG C, and then water quenching is carried out; and the tempering heating temperature is 600-700 DEG C. The large heat input welding 670MPa-grade steel plate has good energy welding performance and aging impact performance, and can be effectively used as a welding structure material to be applied to the field of ocean engineering.

Description

technical field [0001] The invention relates to a metal material and a manufacturing method thereof, in particular to a steel material and a manufacturing method thereof. Background technique [0002] The offshore platform is a super-large welded steel structure located on the sea, and it is a landmark facility in marine resource development projects. Correspondingly, steel for offshore platforms plays the most important role in ensuring the safety of marine facilities as steel for engineering structures. Offshore platforms are used in severe marine working environments such as waves, sea tides, storms and extremely cold drift ice, and support drilling equipment with a total weight of more than hundreds of tons. These usage characteristics determine that steel for marine engineering needs to have performance indicators such as high strength, high toughness, fatigue resistance, good weldability, cold workability, and seawater corrosion resistance. [0003] The study found t...

AI Technical Summary

Problems solved by technology

In order to improve the welding efficiency of large-scale engineering structures and ensure the safety and reliability of their use, single-sided submerged arc welding, gas-electric welding, electroslag welding and other high-input energy welding technologies with high welding efficiency have been adopted one after another. High-strength steel brings new problems, that is, the strength and toughness of the welding heat-affected zone (HAZ) deteriorate, and defects such as welding cold cracks are prone to occur

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