Hull structural steel adapting to high heat input welding and smelting method thereof

Abstract

The invention discloses hull structural steel adapting to high heat input welding, which comprises the following chemical components in percentage by mass: 0.06 to 0.14 percent of C, 0.10 to 0.50 percent of Si, 0.80 to 1.80 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.008 percent of S, 0.020 to 0.050 percent of Nb, 0.006 to 0.030 percent of Ti, 0.0030 to 0.0100 percent of N, 0.015 to 0.045 percent of Al, 0.03 to 0.10 percent of V and the balance of Fe and inevitable impurities. The hull structural steel has the process characteristics that: the Ti is conveyed in a mode of steel wires formed by wrapping alloy powder by steel belts, and the addition process of the Ti is synchronous with the casting process, so that the alloying is more uniform, generated TiN mass points are finer and more dispersed, and the capacity of inhibiting grain growth is higher; and the production process is simple and convenient, and the method is suitable for batch production. When steel plates produced by the smelting method are subjected to high heat input welding under the condition of more than 50 kJ / cm, the toughness of welding heat affected zones is high.

Description

technical field [0001] The invention belongs to the field of low-alloy steel manufacturing, and relates to a hull structural steel, in particular to a hull structural steel suitable for high heat input welding and a smelting method thereof. Background technique [0002] Prior to the present invention, there have been some published reports of steels for high heat input welding. For example, the patent applied by Kawasaki Iron and Steel Co., Ltd. "High heat input welding steel with heat input above 500kJ / cm and its manufacturing method" (application number 96105716.8) and the patent declared by Wuhan Iron and Steel Company "High heat input welding non-quenched and tempered high toughness low temperature Steel and its manufacturing method” (application number 01128316.5). The common feature of these technologies is the addition of B, the use of BN and Ca or Re oxides to inhibit the grain growth of the welding heat-affected zone and improve the performance of the heat-affected...

AI Technical Summary

Problems solved by technology

[0006] Provide a method for manufacturing low-alloy high-strength steel plates suitable for high heat input welding, the purpose is to solve the problems that the second phase particles are large, reduce the toughness of the base metal, and not meet the requirements of high heat input

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