E550-W100 ultrahigh-strength ship plate steel and manufacturing method thereof

Abstract

The invention discloses E550-W100 ultrahigh-strength ship plate steel. The E550-W100 ultrahigh-strength ship plate steel comprises the following chemical components in percentage by mass: 0.04%-0.12%of C, 0.15%-0.35% of Si, 1.50%-1.70% of Mn, less than or equal to 0.020% of P, less than or equal to 0.0030% of S, 0.030%-0.060% of V, 0.010%-0.030% of Nb, 0.030%-0.080% of Alt, 0.005%-0.030% of Ti, 0.0005%-0.0040% of Ca and less than or equal to 0.0060% of N, wherein (Alt.N) / Ti is controlled to be 0.010 to 0.030. The yield strength of an obtained steel plate is larger than or equal to 550 MPa, the tensile strength of the steel plate is larger than or equal to 670 MPa, the steel plate is suitable for high-strength ship plate steel with the welding line energy within the range of 100 kJ / cm, andthe average impact energy of the HAZ of the steel plate at the temperature of -40 DEG C is 55 J or above.

Description

technical field [0001] The invention relates to the technical field of iron and steel production, in particular to an E550-W100 ultra-high-strength ship plate steel and a manufacturing method thereof. Background technique [0002] Steels for high heat input welding are widely used. For example, in the shipbuilding industry, the shipbuilding efficiency of ordinary ship plates is only a quarter of that of high heat input welding ship plates. When the country cannot produce it, it can only be imported from abroad, but the price is expensive. The high heat input welding method is the most practical way to improve the efficiency of welding construction and reduce costs. Steel for high heat input welding is one of the key development goals of my country's iron and steel industry and has broad market prospects. [0003] When the welding heat input is greater than 50kJ / cm, it is high-energy welding. When the welding heat input of traditional steel plates is greater than 50kJ / cm, th...

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Problems solved by technology

[0003] When the welding heat input is greater than 50kJ / cm, it is high-energy welding. When the welding heat input of traditional steel plates is greater than 50kJ / cm, the mechanical properties of the welded joint will be seriously reduced due to the excessive coarsening of the heat-affected zone. It is lower than the standard requirements of the base metal steel plate, and research and development of steel for high-energy-input welding is an effective way to solve the deterioration of low-temperature toughness in the heat-affected zone of high-energy-input welding

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