Micro-alloying compound cored wire for high-strength steel

Abstract

The invention relates to a micro-alloying compound cored wire for high-strength steel, comprising a carbon steel sheath and a powdery core, wherein the core is prepared from the following chemical components by weight percent: 23 to 28 wt% of Ca, 51 to 55 wt% of Si, 0.65 to 1.5 wt% of Mg, 1.3 to 2.5 wt% of Ba, 0.6 to 1.0 wt% of Re, 0.6 to 1.2 wt% of B, 1.6 to 3.5 wt% of Zr, 1.3 to 2.8 wt% of Ti, 0.6 to 1.2 wt% of Nb, and balance of ferrum and inevitable impurities. The invention reduces the content of C in high-strength steel through reasonably designing the chemical components and simultaneously and greatly enhances the grain sizes in continuous casting billets so that the grains are refined. The mechanical properties of the steel can be obviously improved, and the transverse impact properties of the steel are obviously enhanced to approximate to longitudinal impact value. Besides, the invention well solves the problems of center segregation and center porosity of the continuous casting billets, nonuniform impurity distribution, and the like.

Description

Technical field

[0001] The invention relates to a cored wire, in particular to a microalloyed composite cored wire for high-strength steel. Background technique

[0002] With the rapid development of my country's national economy, the development of the domestic steel industry has also grown rapidly. In recent years, my country's steel production has been ranked first in the world. China is a veritable steel power, but it is not a steel power. High-strength, high-toughness, and high-value-added steel products still need to be imported in large quantities from abroad. Therefore, the development of high-performance, high-value-added steel products to make China a strong steel country as soon as possible has always been the direction of our people, especially the metallurgical industry.

[0003] In addition to scientific rolling and heat treatment processes for high-strength steel plates with excellent performance, reasonable composition design is also the key to production. Althou...

Examples

Embodiment 1

[0020] Example 1: The particle size of the powdered particles in the cored wire powdered inner core is 1 to 1.2 mm, and the powdered inner core is wrapped by a carbon steel outer skin to make a cored wire with a diameter of 13 mm. The carbon steel outer skin is made of 08Al steel strip with a thickness of 0.3-0.4 mm, and the element composition and mass in the powdered inner core are: Ca 22%, Si 51%, Mg 0.65%, Ba 2.5%, Re 0.6 %, B 1.2%, Zr 1.6%, Ti.2.8%, Nb 0.6%, the balance is iron and unavoidable impurities.

Embodiment 2

[0021] Example 2: The particle size of the powdery particles in the powdered core of the cored wire is 1.2-1.5 mm, and the powdered core is wrapped by a carbon steel outer skin to make a cored wire with a diameter of 13 mm. The carbon steel outer skin adopts a low-carbon steel strip with a thickness of 0.3-0.4 mm. The element composition and mass% in the powdery inner core are: Ca 28%, Si 55%, Mg 1.5%, Ba 1.3%, Re 1.0%, B 0.6%, Zr 3.5%, Ti 1.3%, Nb 1.2%, the balance is iron and inevitable impurities.

Embodiment 3

[0022] Example 3: The particle size of the powdery particles in the cored wire powdered inner core is 1 to 1.5 mm, and the powdered inner core is wrapped by a carbon steel outer skin to make a cored wire with a diameter of 13 mm. The carbon steel outer skin is made of 08Al steel strip with a thickness of 0.3-0.4 mm. The element composition and mass% in the powdered inner core are: Ca 25%, Si 53%, Mg 1.0%, Ba 2.0%, Re 0.8 %, B 0.8%, Zr 2.0%, Ti 2.0%, Nb 0.8%, the balance is iron and unavoidable impurities.

[0023] In order to further verify the effects of the present invention, the inventors conducted the following performance tests, and the results are as follows.

[0024] 1. Using the cored wire obtained in Example 3, add 2 kg of powdered core per ton of molten steel (KD type high-strength steel, Rm≥800MPa, impact toughness CV=250-300J, -20℃) Cored wire. Then analyze the slag samples before and after the cored wire is added, and the results are shown in Table 1.

[0025] Table 1...

Technical field

[0001] The invention relates to a cored wire, in particular to a microalloyed composite cored wire for high-strength steel. Background technique

[0002] With the rapid development of my country's national economy, the development of the domestic steel industry has also grown rapidly. In recent years, my country's steel production has been ranked first in the world. China is a veritable steel power, but it is not a steel power. High-strength, high-toughness, and high-value-added steel products still need to be imported in large quantities from abroad. Therefore, the development of high-performance, high-value-added steel products to make China a strong steel country as soon as possible has always been the direction of our people, especially the metallurgical industry.

[0003] In addition to scientific rolling and heat treatment processes for high-strength steel plates with excellent performance, reasonable composition design is also the key to production. Althou...

Examples

Embodiment 1

[0020] Example 1: The particle size of the powdered particles in the cored wire powdered inner core is 1 to 1.2 mm, and the powdered inner core is wrapped by a carbon steel outer skin to make a cored wire with a diameter of 13 mm. The carbon steel outer skin is made of 08Al steel strip with a thickness of 0.3-0.4 mm, and the element composition and mass in the powdered inner core are: Ca 22%, Si 51%, Mg 0.65%, Ba 2.5%, Re 0.6 %, B 1.2%, Zr 1.6%, Ti.2.8%, Nb 0.6%, the balance is iron and unavoidable impurities.

Embodiment 2

[0021] Example 2: The particle size of the powdery particles in the powdered core of the cored wire is 1.2-1.5 mm, and the powdered core is wrapped by a carbon steel outer skin to make a cored wire with a diameter of 13 mm. The carbon steel outer skin adopts a low-carbon steel strip with a thickness of 0.3-0.4 mm. The element composition and mass% in the powdery inner core are: Ca 28%, Si 55%, Mg 1.5%, Ba 1.3%, Re 1.0%, B 0.6%, Zr 3.5%, Ti 1.3%, Nb 1.2%, the balance is iron and inevitable impurities.

Embodiment 3

[0022] Example 3: The particle size of the powdery particles in the cored wire powdered inner core is 1 to 1.5 mm, and the powdered inner core is wrapped by a carbon steel outer skin to make a cored wire with a diameter of 13 mm. The carbon steel outer skin is made of 08Al steel strip with a thickness of 0.3-0.4 mm. The element composition and mass% in the powdered inner core are: Ca 25%, Si 53%, Mg 1.0%, Ba 2.0%, Re 0.8 %, B 0.8%, Zr 2.0%, Ti 2.0%, Nb 0.8%, the balance is iron and unavoidable impurities.

[0023] In order to further verify the effects of the present invention, the inventors conducted the following performance tests, and the results are as follows.

[0024] 1. Using the cored wire obtained in Example 3, add 2 kg of powdered core per ton of molten steel (KD type high-strength steel, Rm≥800MPa, impact toughness CV=250-300J, -20℃) Cored wire. Then analyze the slag samples before and after the cored wire is added, and the results are shown in Table 1.

[0025] Table 1...

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