Production process of HRB400E reinforcing steel bar for reinforced concrete

Abstract

The invention discloses a production process of an HRB400E reinforcing steel bar for reinforced concrete, and belongs to the field of production of reinforced concrete. The steel bar comprises the following components in percentage by mass: 0.25% of C, 0.8% of Si, 1.6% of Mn, 0.45% of P, 0.45% of S and other alloy elements, and the balance of Fe and impurity elements. The production process for the reinforced concrete comprises the steps of water smelting, inclusion treatment, continuous casting, rolling, cooling and the like. According to the production process, the types, the sizes and the number of the inclusions in the reinforcing steel bars are specially controlled. And the requirements of low-cost production and high standard of the HRB400E steel bar for reinforced concrete are met.

Description

[0001] The technical solution provided by the present invention for realizing the above-mentioned is as follows:

[0002] 1. A production process of HRB400E steel bars for reinforced concrete, comprising alloy elements such as C: 0.25%, Si: 0.8% Mn: 1.6%, P: 0.45%, S: 0.45% by mass fraction, and the remainder being Fe and impurity elements.

[0003] 2. The melting point of iron ore is not fixed, because it is a mixture, and its melting point depends on its composition. Iron ore is a mineral aggregate containing iron or iron compounds. Iron is gradually selected through crushing, grinding, magnetic separation, flotation, gravity separation and other procedures.

[0004] 3. The melting point of molten iron is 1535℃ (iron ore to molten steel). The temperature of smelting molten iron is 1500℃-1700℃. The iron and steel furnace can be burned up to 2000℃. The solidification point of molten steel is 1065℃, the boiling point is 2360℃, and the liquidus temperature of molten steel fluctuates to 1700℃ with different components (the content of CSP and other elements in molten steel).

[0005] 4. The hot metal desulfurization method is the mechanical stirring method (KR method): the hot metal is rotated mechanically and 3-5 kg ​​of desulfurizer Cao or Mgo is sprayed into the hot metal per ton, the sulfur content is reduced to 0.002%, the desulfurization rate is higher than 90%, and the desulfurization temperature of the hot metal is above 1300°C. The desulfurizer reacts with the sulfide through stirring to achieve desulfurization.

[0006] 5. The billet temperature of continuous casting is generally controlled between 1300℃ and 1500℃, depending on the type of steel and process requirements. This is because the billet temperature determines the internal structure, grain size and surface quality of the billet. During the continuous casting process, it is also necessary to control the temperature of the molten steel to perform deep shaping, back blowing, continuous water spraying and other operations to ensure the billet quality. The measurement method of the billet temperature of continuous casting: one is to use temperature (such as immersion anode thermometer, thermocouple thermometer, etc.) to measure the temperature of the molten steel in real time, and continuously adjust the temperature during the continuous casting process to ensure that the billet temperature is stable and controllable. In short, the billet temperature of continuous casting is one of the important factors that determine the billet quality.

[0007] 6. The steel billet of the present invention is rolled into steel bars by rolling equipment, and the composition needs to be controlled according to the national standard GB1499.2-2007, and water-piercing rolling is adopted.

[0008] 7. Finally, bundle, package and palletize for storage and transportation.

[0009] 8. The present invention is widely used in the fields of construction, transportation infrastructure construction, etc. It is a steel product with the largest output, stable quality, high standards and high requirements, and simple process.

[0010] 9. The technical principle of the present invention is as follows: In the rolling production process of a HRB400E steel bar production process for reinforced concrete, the variables from ingot to finished product are large, the rolling speed is fast, and it has high thermal stability. It is mainly generated by reaction in molten steel and does not dissolve during heating and rolling. If it further plays a role in promoting the nucleation of voxels during the cooling process of the steel bar, the microstructure of the manifested steel bar will achieve the effect of fine grain strengthening.

[0011] 10. The present invention adopts Mgo / Cao additives, which are low in cost, abundant in source, simple to prepare, and suitable for mass production of HRB400E steel bar production process for reinforced concrete, reducing the consumption of precious alloy resources, reducing production costs, and facilitating promotion and application.

[0012] 11. Attachment Figure 1 It is a production process diagram of HRB400E steel bar for reinforced concrete.

Claims

1. A HRB400E steel bar for reinforced concrete, characterized by comprising the following chemical compositions by mass fraction: alloying elements such as C: 0.25%, Si: 0.8%, Mn: 1.6%, P: 0.45%, S: 0.45%, and the remainder being Fe and impurity elements.

2. A production process of HRB400E steel bars for reinforced concrete Converter smelting: iron ore is smelted to obtain molten iron. In this process, the molten iron needs to be desulfurized to remove the sulfur. The total loading capacity of the converter is usually 50t, and the loading error is controlled within the range of ±0.5t.

3. A HRB400E steel bar refining for reinforced concrete: single slag process is used for smelting, slag is smelted throughout the process, and the slag basicity is controlled between 2.7 and 3.

3. The smelting end point control target is [C] 0.25%, [P] 0.045%, [S] 0.045%. The steel release time is not less than 2 minutes.

4. A HRB400E steel bar continuous casting machine for reinforced concrete: the refined molten steel is cast into steel billets through the continuous casting machine.

5. Rolling of HRB400E steel bars for reinforced concrete: The steel billet is rolled into steel bars by a rolling device. During the rolling process, a microalloying production process is required, and alloying elements such as silicon manganese, silicon iron, and vanadium nitrogen alloy are added. At the same time, in order to control the carbon equivalent of the steel billet, it is necessary to control the composition according to the national standard GB 1499.2-2007, and adopt water-penetrating rolling.

6. HRB400E steel bar bundling, packaging and palletizing for reinforced concrete: The rolled steel bars are bundled, packaged and palletized for storage and transportation.

7. In addition, the anti-rust treatment of HRB400E steel bars is also an important part of the production process. Common anti-rust treatment methods include painting and hot-dip galvanizing anti-rust agents, etc., to extend the service life of steel bars and reduce maintenance costs.

8. The above is only the general process of HRB400E steel bar production process. The specific production process and process parameters may vary depending on different equipment.

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