Steel for high heat input welding ship body structure and manufacturing method of steel

Abstract

The invention discloses steel for a high heat input welding ship body structure and a manufacturing method of the steel, and relates to the technical field of steel production. The steel is prepared from the following chemical components in percentage by mass: 0.05%-0.08% of C, 0.10%-0.30% of Si, 1.20%-1.50% of Mn, less than or equal to 0.015% of P, less than or equal to 0.0030% of S, 0.010%-0.030% of Nb, 0.020%-0.040% of V, 0.006%-0.020% of Ti, less than or equal to 0.10% of Cr, less than or equal to 0.10% of Mo, 0.10%-0.20% of Ni, 0.005%-0.015% of Al, 0.0008%-0.0015% of Mg, less than or equal to 0.0050% of N, no Ca and the balance of Fe and inevitable impurities. A micro-alloying process is adopted to obtain pure molten steel of nanoscale oxide, a rolling cooling process is adopted to obtain a steel plate taking acicular ferrite as a main component, so that the high heat input welding requirement of a product is met.

Description

technical field [0001] The invention relates to the technical field of steel production, in particular to a steel for large heat input welding hull structure and a manufacturing method thereof. Background technique [0002] With the continuous development of the economy, my country's export volume is increasing day by day, the shipping volume is increasing, and the tonnage of shipbuilding is also increasing. The steel plate grade, thickness and quality requirements for shipbuilding are getting higher and higher. In the welding process of the ship plate, a large welding energy is required to meet the welding demand. [0003] Thick-walled ship plate products need thick-walled slabs to be manufactured. In the smelting process, it is difficult to control the inclusions of thick-walled slabs, and the core of the slab is severely segregated, and it is easy to produce a large number of alumina inclusions and manganese sulfide inclusions. Among them, the heat-affected zone and weldi...

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Problems solved by technology

[0003] Thick-walled ship plate products need thick-walled slabs to be manufactured. In the smelting process, it is difficult to control the inclusions of thick-walled slabs, and the core of the slab is severely segregated, and it is easy to produce a large number of alumina inclusions and manganese sulfide inclusions. Among them, the heat-affected zone and welding zone will cause secondary accumulation of oxides, and the performance of the heat-affected zone and welding zone is very different from the regional performance of the steel plate body, which will cause regional performance differences of the ship plate and affect the performance of the hull

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