Production technology of finish-rolled ribbed bars

Abstract

The invention belongs to the technical field of ferrous metallurgy technology, and especially provides a production technology of finish-rolled ribbed bars. The technological line provided by the invention comprises steps of billet heating, rolling, on-line controlled cooling, cold bed natural cooling, scaling, and stack cooling. Medium-carbon steel is adopted in square billets with a dimension of 150mm*150mm. A three-stage heating method comprising preheating, heating, and soaking is adopted in the heating process. An initial rolling temperature is controlled at 1000 DEG C to 1100 DEG C in the rolling process. In the on-ling controlled cooling process, the temperature is controlled at 920 to 1000 DEG C when the billets are delivered into a water tank; a one-step cooling method is adopted; self-tempering temperatures of PSB785 and PSB830 are controlled at 480 to 550 DEG C; and a self-tempering temperature of PSB930 is controlled at 430 to 480 DEG C. The cooling speed is controlled at 1-5 DEG C / s in the cold bed natural cooling process. Off-line stack cooling under a temperature of 150 to 350 DEG C is carried out in the stack cooling process, wherein a stack cooling time is lower than 48 hours. Various properties of the finish-rolled ribbed bars provided by the invention can completely satisfy the requirements of users.

Description

technical field

[0001] The invention belongs to the technical field of iron and steel metallurgy technology, and in particular provides a production technology of finish-rolled threaded steel bars. technical background

[0002] Finish-rolled threaded steel bars are widely used in continuous beams and large-scale frame structures in large-scale water conservancy projects, industrial and civil buildings, large and medium-span bridges for highways and railways, nuclear power plants and ground anchors and other projects. It has the advantages of simple connection and anchorage, strong adhesion, safe and reliable tension anchorage, and convenient construction. It can also save steel bars, reduce the area of ​​components, and reduce the weight of components, which has significant social and economic benefits.

[0003] There are four grades of fine-rolled threaded steel bars classified according to their strength grades, namely PSB785, PSB830, PSB930, and PSB1080. The production p...

Examples

Embodiment 1

[0036] Brand: PSB830, specification: Φ32mm.

[0037] Billet heating→rolling→on-line controlled cooling→natural cooling on upper cooling bed→length cutting→stack cooling.

[0038] ●The chemical composition is shown in Table 3, and the raw material is: 150×150×12000mm continuous casting billet.

[0039] Table 3 Chemical Composition of Finished Rebars Unit: (%)

[0040] C

Si

mn

V

P

S

Fe

0.40

1.60

0.94

0.11

0.016

0.009

margin

[0041] The billet is subjected to three-stage heating treatment, in which the temperature in the preheating section is ≤850°C, the temperature in the heating section is 1100°C-1170°C, the temperature in the soaking section is 1090°C-1160°C, and the total heating time is 100-150 minutes;

[0042] ●In the rolling process, a total of 14 rolling mills are used, the starting rolling temperature is 1020-1100°C, and the final rolling speed is controlled at 4.0-5.5m / s;

[...

Embodiment 2

[0049] Brand: PSB930, specification: Φ25mm.

[0050] Billet heating→rolling→on-line controlled cooling→natural cooling on upper cooling bed→length cutting→stack cooling.

[0051] ●The chemical composition is shown in Table 5, and the raw material is: 150×150×12000mm continuous casting billet.

[0052] Table 5 Chemical Composition of Finished Rebars Unit: (%)

[0053] C

Si

mn

V

P

S

Fe

0.42

1.57

0.86

0.10

0.022

0.008

margin

[0054] The billet is subjected to three-stage heating treatment, in which the temperature of the preheating section is ≤850°C, the temperature of the heating section is 1090°C-1160°C, the temperature of the soaking section is 1080°C-1150°C, and the total heating time is 100-150 minutes;

[0055]●In the rolling process, a total of 14 rolling mills are used, the starting rolling temperature is 1000-1080 ℃, and the final rolling speed is controlled at 6.0-7.5m / s;

[0...

technical field

[0001] The invention belongs to the technical field of iron and steel metallurgy technology, and in particular provides a production technology of finish-rolled threaded steel bars. technical background

[0002] Finish-rolled threaded steel bars are widely used in continuous beams and large-scale frame structures in large-scale water conservancy projects, industrial and civil buildings, large and medium-span bridges for highways and railways, nuclear power plants and ground anchors and other projects. It has the advantages of simple connection and anchorage, strong adhesion, safe and reliable tension anchorage, and convenient construction. It can also save steel bars, reduce the area of ​​components, and reduce the weight of components, which has significant social and economic benefits.

[0003] There are four grades of fine-rolled threaded steel bars classified according to their strength grades, namely PSB785, PSB830, PSB930, and PSB1080. The production p...

Examples

Embodiment 1

[0036] Brand: PSB830, specification: Φ32mm.

[0037] Billet heating→rolling→on-line controlled cooling→natural cooling on upper cooling bed→length cutting→stack cooling.

[0038] ●The chemical composition is shown in Table 3, and the raw material is: 150×150×12000mm continuous casting billet.

[0039] Table 3 Chemical Composition of Finished Rebars Unit: (%)

[0040] C

Si

mn

V

P

S

Fe

0.40

1.60

0.94

0.11

0.016

0.009

margin

[0041] The billet is subjected to three-stage heating treatment, in which the temperature in the preheating section is ≤850°C, the temperature in the heating section is 1100°C-1170°C, the temperature in the soaking section is 1090°C-1160°C, and the total heating time is 100-150 minutes;

[0042] ●In the rolling process, a total of 14 rolling mills are used, the starting rolling temperature is 1020-1100°C, and the final rolling speed is controlled at 4.0-5.5m / s;

[...

Embodiment 2

[0049] Brand: PSB930, specification: Φ25mm.

[0050] Billet heating→rolling→on-line controlled cooling→natural cooling on upper cooling bed→length cutting→stack cooling.

[0051] ●The chemical composition is shown in Table 5, and the raw material is: 150×150×12000mm continuous casting billet.

[0052] Table 5 Chemical Composition of Finished Rebars Unit: (%)

[0053] C

Si

mn

V

P

S

Fe

0.42

1.57

0.86

0.10

0.022

0.008

margin

[0054] The billet is subjected to three-stage heating treatment, in which the temperature of the preheating section is ≤850°C, the temperature of the heating section is 1090°C-1160°C, the temperature of the soaking section is 1080°C-1150°C, and the total heating time is 100-150 minutes;

[0055]●In the rolling process, a total of 14 rolling mills are used, the starting rolling temperature is 1000-1080 ℃, and the final rolling speed is controlled at 6.0-7.5m / s;

[0...

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