Low-temperature impact resistance high-elongation Q345 hot rolled strip steel and production method

A technology for hot-rolled strip steel and a production method, which is applied in the field of metallurgy, can solve the problems of difficulty in controlling the cooling rate, etc., and achieves the effects of saving the amount of alloy and rolling load, strong surface quality and adhesion, and reducing production costs.

Inactive Publication Date: 2017-10-24
TANGSHAN STAINLESS STEEL +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Invention Patent Application No. 201310231768.5 discloses a flexible manufacturing method for hot-rolled structural steel plates. It adopts two-stage controlled rolling and front-stage rapid cooling process. It is difficult to control the cooling rate of 30-50°C / s for the strip cooling line of different specifications

Method used

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  • Low-temperature impact resistance high-elongation Q345 hot rolled strip steel and production method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] In this example, the low-temperature impact-resistant high-elongation Q345E hot-rolled steel strip has a thickness of 3.0mm, and its chemical composition and mass percentage are: C: 0.18%, Mn: 0.50%, S: 0.002%, P: 0.010%, Si : 0.02%, Als: 0.038%, N: 0.0020%, and the rest are iron and unavoidable impurities.

[0032] The production method includes steelmaking, heating, rolling and cooling processes, and the specific process steps are as follows:

[0033] (1) Steelmaking process: the smelting process of pure steel is adopted, and the blast furnace molten iron is treated by top-bottom combined blowing converter and LF refining furnace. The chemical composition and mass percentage of tapping molten steel are: C: 0.18%, Mn: 0.50% , S: 0.002%, P: 0.010%, Si: 0.02%, Als: 0.038%, N: 0.0020%, and the rest are iron and unavoidable impurities.

[0034] (2) Heating process: molten steel is continuously cast into slabs, and the heating temperature of the slabs is 1200°C.

[0035] ...

Embodiment 2

[0040] In this example, the low-temperature impact-resistant high-elongation Q345E hot-rolled steel strip has a thickness of 5.5mm, and its chemical composition and mass percentage are: C: 0.18%, Mn: 0.49%, S: 0.006%, P: 0.020%, Si : 0.02%, Als: 0.041%, N: 0.0046%, the rest is iron and unavoidable impurities.

[0041] The production method includes steelmaking, heating, rolling and cooling processes, and the specific process steps are as follows:

[0042] (1) Steelmaking process: the smelting process of pure steel is adopted, and the blast furnace molten iron is treated by top-bottom combined blowing converter and LF refining furnace. The chemical composition and mass percentage of tapping molten steel are: C: 0.18%, Mn: 0.49% , S: 0.006%, P: 0.020%, Si: 0.02%, Als: 0.041%, N: 0.0046%, and the rest are iron and unavoidable impurities.

[0043] (2) Heating process: molten steel is continuously cast into slabs, and the heating temperature of the slabs is 1190°C.

[0044] (3) R...

Embodiment 3

[0048] In this example, the low-temperature impact-resistant high-elongation Q345E hot-rolled steel strip has a thickness of 2.0mm, and its chemical composition and mass percentage are: C: 0.17%, Mn: 0.45%, S: 0.012%, P: 0.020%, Si : 0.025%, Als: 0.035%, N: 0.0035%, the rest is iron and unavoidable impurities.

[0049] The production method includes steelmaking, heating, rolling and cooling processes, and the specific process steps are as follows:

[0050] (1) Steelmaking process: the smelting process of pure steel is adopted. The blast furnace molten iron is treated by the top-bottom combined blowing converter and LF refining furnace. The chemical composition and mass percentage of the tapping molten steel are: C: 0.17%, Mn: 0.45% , S: 0.012%, P: 0.020%, Si: 0.025%, Als: 0.035%, N: 0.0035%, and the rest are iron and unavoidable impurities.

[0051] (2) Heating process: molten steel is continuously cast into slabs, and the heating temperature of the slabs is 1200°C.

[0052]...

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Abstract

The invention discloses a low-temperature impact-resistant high-elongation Q345E hot-rolled strip steel and a production method. The chemical composition and mass percentage of the hot-rolled strip steel are: C: 0.15-0.18%, Mn: 0.4-0.7%, S≤0.015%, P≤0.025%, Si≤0.03%, Als≥0.015%, N≤0.0060%, the rest is iron and unavoidable impurities; production methods include steelmaking, heating, rolling and cooling processes. The invention applies the principle of controlled rolling and controlled cooling bainite phase transformation strengthening, reduces the cost of the alloy, improves the strength and low-temperature impact toughness, and the surface quality and adhesion of the low-silicon and low-phosphorus hot-dip galvanized zinc layer are strong, and the corrosion resistance is strong. , to meet the needs of photovoltaic brackets, power towers, power towers, engineering construction scaffolding and other hot-dip galvanized structural steel in cold regions, which is conducive to increasing market share and can generate great economic benefits.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a low-temperature shock-resistant high-elongation Q345E hot-rolled steel strip and a production method. Background technique [0002] With the continuous development of my country's economic construction, the application of low-alloy high-strength structural steel is becoming more and more extensive. Q345E low-alloy high-strength steel is exported in large quantities. It has excellent properties such as high strength, high toughness, impact resistance, and corrosion resistance. It has become one of the first-choice materials for engineering structure design and is widely used in photovoltaic brackets, power towers, engineering construction scaffolding and others. Hot-dip galvanized structural parts have broad market prospects. [0003] As the production capacity of China's iron and steel industry continues to expand, the pressure of competition within the industry...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/04C22C38/02C22C38/06C21D8/02
CPCC22C38/04C21D8/0226C21D2211/002C21D2211/005C22C38/02C22C38/06
Inventor 张玉文贾丽慧李建设刘爱平任振远吕苗苗方锡婕陈秋良
Owner TANGSHAN STAINLESS STEEL
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