Production process of reinforcing steel bars with specifications of phi 12mm*5 and phi 14mm*4

Abstract

The invention relates to the technical field of iron and steel smelting, in particular to a production process of reinforcing steel bars with the specifications of phi 12mm * 5 and phi 14mm * 4, which comprises the following steps: a steelmaking process: feeding raw materials such as semi-steel and scrap steel together with coke into a converter for smelting; continuous casting forming: pouring the obtained molten steel into a casting mold, and cooling and solidifying to form a steel billet; and hot rolling treatment is conducted, specifically, the steel billet is heated and pressed through a rolling mill, and the required steel bars with the specifications of phi 12 mm * 5 and phi 14 mm * 4 are obtained. The yield, the quality stability and the production efficiency of the reinforcing steel bars are improved, and the production targets of high quality, high efficiency, low cost, environmental protection and energy conservation are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of steel smelting, and specifically to a and Specification steel bar production process. Background Art

[0002] and The standard steel bars are round tubes with diameters of 12mm and 14mm and wall thicknesses of 5mm and 4mm. and The process of producing standard steel bars has the problem of scrapping the final product due to defects in the billet, such as rotten longitudinal bars and serrated longitudinal bars, which affects product quality, brings economic losses to the company, and wastes the country's non-renewable resources. Summary of the invention

[0003] In order to solve the defects in the prior art, the present invention provides a and Standard steel bar production process. The present invention uses semi-steel and scrap steel as the main raw materials, and by optimizing the process parameters of each process such as steelmaking process, continuous casting, hot rolling treatment, etc., improves the steel bar yield, quality stability and production efficiency, and achieves the production goals of high quality, high efficiency, low cost, environmental protection and energy saving.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides a and The production process of standard steel bars includes the following steps:

[0006] Steelmaking process: Raw materials such as semi-steel and scrap steel are fed into a converter together with coke for smelting;

[0007] Continuous casting: pour the molten steel into a mold, cool and solidify to form a steel billet;

[0008] Hot rolling: The steel billet is heated and pressed through a rolling mill to obtain the desired and Specification steel bars.

[0009] Preferably, in the steelmaking process, the mass ratio of semi-steel to scrap steel is (81-85):(3-6).

[0010] Preferably, in the steelmaking process, the components of the molten steel at the converter end point are controlled to be C 0.05-0.10%, P≤0.025%, and S≤0.040%.

[0011] Preferably, in the steelmaking process, the tapping temperature is controlled at 1670-1690°C for tapping and 1650-1660°C for continuous casting.

[0012] Preferably, in the steelmaking process, the nitrogen blowing time of the molten steel after steelmaking is completed is greater than 6 minutes.

[0013] Preferably, during the continuous casting process, the liquid level at the start of drawing in the tundish is controlled to be ≥500mm, the liquid level in the middle and late stages is controlled to be >600mm, and the liquid level fluctuation is controlled to be ±100mm.

[0014] Preferably, during the continuous casting process, the drawing speed is controlled at 2.5 to 3.2 m / min.

[0015] Preferably, during the hot rolling process, the starting rolling temperature is 980°C to 1120°C, the finishing rolling temperature is ≤1050°C, and the tempering temperature after rolling is ≥860°C.

[0016] Preferably, the production process also includes cooling and shearing, inspection and packaging steps.

[0017] Preferably, the shearing temperature during the cooling and shearing process is ≤250°C.

[0018] The beneficial effects of the present invention are:

[0019] The present invention and The production process of standard steel bars aims to improve the yield rate, quality stability and production efficiency of steel bars by optimizing various links such as raw material selection, steelmaking process, continuous casting, hot rolling, cooling and shearing, inspection and packaging, so as to achieve the production goals of high quality, high efficiency, low cost and environmental protection and energy saving. This process is particularly suitable for large-scale and high-precision steel bar production to meet the needs of industries such as construction, machinery, and automobiles. This process not only meets market demand, but also brings significant economic and social benefits to enterprises, and has broad application prospects and promotion value. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0021] Example 1

[0022] This embodiment provides a and The production process of standard steel bars includes the following steps:

[0023] Raw material selection:

[0024] The ore billet ensures TFe≥55%, S≤0.12%, and P≤0.12%.

[0025] Steelmaking process:

[0026] Raw materials such as semi-steel and scrap steel are fed into the converter along with coke for smelting;

[0027] Raw material consumption: 81t of semi-steel and 3t of scrap steel. The scrap steel entering the furnace is self-produced high-quality scrap steel (cut ends and ends of continuous casting, waste billets, and rolling scrap steel returned from steel rolling) and a small amount of self-produced slag steel.

[0028] The control target of molten steel composition at the end of converter is: C 0.05%, P≤0.025%, S≤0.040%;

[0029] Steel tapping temperature: 1670℃ for ladle opening and 1650℃ for continuous pouring (ensuring that the molten steel temperature is ≥1570℃ before nitrogen blowing);

[0030] After steelmaking is completed, the nitrogen blowing time for the molten steel should be greater than 6 minutes. It is strictly forbidden to cause the molten steel to turn over and cool down greatly during nitrogen blowing.

[0031] Continuous casting:

[0032] The obtained molten steel is poured into the casting mold, cooled and solidified to form a billet; the liquid level of the tundish is controlled to be ≥500mm at the beginning of drawing, and the liquid level is controlled to be >600mm in the middle and late stages. The liquid level of the tundish is required to be stable, and the liquid level fluctuation is controlled to be ±100mm; the drawing speed is controlled at 2.5m / min. In terms of production organization, the production rhythm of desulfurization, vanadium extraction, and semi-steel smelting is coordinated to ensure that the liquid level of the continuous casting tundish is >500mm and is not affected.

[0033] Hot rolling treatment:

[0034] The steel billet is heated and pressed through a rolling mill to obtain the required #imgpt18# and #imgpt19# specification steel bars. In the steel rolling production process, the starting rolling temperature is 980℃, the finishing rolling temperature is ≤1050℃, and the tempering temperature after rolling is ≥860℃.

[0035] The size deviation of the rolled piece is ±0.1mm, and there should be no blackheads, warped heads, etc.

[0036] Cooling and shearing:

[0037] The shearing temperature is ≤250℃ and the steel cannot overlap during shearing.

[0038] Inspection and packaging:

[0039] 1. The steel bars are packed by a packing machine, with both ends flat and a round shape.

[0040] 2. Use coils to bundle each bundle of steel bars for fixed-length packaging, and ensure that the bundles are tightly tied.

[0041] 3. 9-meter fixed-length packaging: Each bundle of steel bars must be bundled in no less than 5 times. The ones near both ends must be bundled at 500±50mm from the ends, and the 3 middle times must be even.

[0042] 4. 12-meter fixed-length packaging: Each bundle of steel bars must be bundled in no less than 7 batches. The ones near both ends must be bundled 500±100mm away from the ends, and the 5 batches in the middle must be even.

[0043] 5. The steel bars must be packed and tied tightly with moderate force to prevent them from falling apart.

[0044] 6. Each bundle of packaged steel bars must not contain bent, short, rotten, serpentine, or other steel bars.

[0045] Example 2

[0046] Same as Example 1, except that:

[0047] Steelmaking process:

[0048] The semi-steel loading is 85t and the scrap steel loading is 6t;

[0049] The control target of molten steel composition at the end of converter is: C 0.10%, P≤0.025%, S≤0.040%;

[0050] Steel tapping temperature: 1690℃ for ladle opening and 1660℃ for continuous pouring (ensuring that the molten steel temperature is ≥1570℃ before nitrogen blowing).

[0051] Continuous casting: The pulling speed is controlled at 3.2m / min.

[0052] Hot rolling treatment: The starting rolling temperature is 1120℃, the finishing rolling temperature is ≤1050℃, and the tempering temperature after rolling is ≥860℃.

[0053] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A production process for φ12mm×5 and φ14mm×4 steel bars, characterized in that: The following steps are involved: Steelmaking process: Raw materials such as semi-steel and scrap steel are fed into a converter together with coke for smelting; Continuous casting: pour the molten steel into a mold, cool and solidify to form a steel billet; Hot rolling treatment: The steel billet is heated and pressed through a rolling mill to obtain the required φ12mm×5 and φ14mm×4 specification steel bars.

2. The production process according to claim 1, characterized in that: In the steelmaking process, the mass ratio of semi-steel to scrap steel is (81-85):(3-6).

3. The production process according to claim 1, characterized in that: In the steelmaking process, the components of the molten steel at the converter end point are controlled to be C 0.05-0.10%, P≤0.025%, and S≤0.040%.

4. The production process according to claim 1, characterized in that: In the steelmaking process, the tapping temperature is controlled at 1670-1690°C for tapping and 1650-1660°C for continuous pouring.

5. The production process according to claim 1, characterized in that: In the steelmaking process, the nitrogen blowing time of the molten steel after steelmaking is completed is greater than 6 minutes.

6. The production process according to claim 1, characterized in that: During the continuous casting process, the liquid level at the start of drawing of the tundish is controlled to be ≥500mm, the liquid level in the middle and late stages is controlled to be >600mm, and the liquid level fluctuation is controlled to be ±100mm.

7. The production process according to claim 1, characterized in that: During the continuous casting process, the drawing speed is controlled at 2.5-3.2 m / min.

8. The production process according to claim 1, characterized in that: During the hot rolling process, the starting rolling temperature is 980°C to 1120°C, the finishing rolling temperature is ≤1050°C, and the tempering temperature after rolling is ≥860°C.

9. The production process according to claim 1, characterized in that: The production process also includes cooling and cutting, inspection and packaging steps.

10. The production process according to claim 9, characterized in that: The shearing temperature during the cooling and shearing process is ≤250°C.

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