High-strength hot-rolled reinforcement bar of 830 MPa level, and production technology thereof

A production process, 830mpa technology, applied in the field of steel bar and its production process, can solve the problems of difficulty in ensuring the yield platform, low yield strength of hot-rolled steel bars, etc., to avoid excessive corrosion rate and hardness, good ductility, and reduce connection costs. Effect

Active Publication Date: 2014-01-01
江苏森林建筑新材料股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The yield strength of existing hot-rolled steel bars is relatively low. It is very difficult to make the yield strength of hot-rolled steel bars reach such a high strength as 830MPa and above, and the strength is so high that it is difficult to guarantee the yield platform. Strength may be expressed as a 0.2% strain versus strength

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] The 830MPa grade high-strength hot-rolled steel bar in this example has the following chemical composition by weight: C: 0.38%, Cr: 0.7%, Mn: 0.6%, Mo: 0.25%, Si: 0.2%, Ni: 1.6%, S: 0.025%, P: 0.03%, N: 0.025%, and the balance is Fe.

[0035] The production technology of the 830MPa level high-strength hot-rolled steel bar of the present embodiment is carried out according to the following steps:

[0036] (1) Put the smelted steel bar into the heating furnace and heat it to 1200°C, then quickly cool the steel bar to 640°C through the first online cooling process, and then quench it with water or quenching liquid in the quenching device for 15 seconds, and then pass through The tempering heating furnace is heated to 660°C for tempering, and then cooled to normal temperature through the second cooling process;

[0037] The first cooling process: use water cooling to water-cool the steel bars to 640°C at a cooling rate of 9°C / s;

[0038] The second cooling process: the co...

Embodiment 2

[0045] The 830MPa grade high-strength hot-rolled steel bars in this example have the following chemical composition by weight: C: 0.41%, Cr: 0.8%, Mn: 0.7%, Mo: 0.15%, Si: 0.25%, Ni: 1.8%, S: 0.015%, P: 0.025%, N: 0.015%, and the balance is Fe.

[0046] The production technology of the 830MPa level high-strength hot-rolled steel bar of the present embodiment is carried out according to the following steps:

[0047] (1) Put the smelted steel bar into the heating furnace and heat it to 1100°C, then cool the steel bar quickly to 650°C through the first online cooling process, and then quench it with water or quenching liquid in the quenching device for 16 seconds, and then pass through The tempering heating furnace is heated to 600°C for tempering, and then cooled to normal temperature through the second cooling process;

[0048] The first cooling process: use water cooling to water-cool the steel bars to 650°C at a cooling rate of 10°C / s;

[0049] The second cooling process: t...

Embodiment 3

[0056] The 830MPa grade high-strength hot-rolled steel bar in this embodiment has the following chemical composition by weight: C: 0.43%, Cr: 0.9%, Mn: 0.8%, Mo: 0.2%, Si: 0.3%, Ni: 2%, S: 0.013%, P: 0.015%, N: 0.012%, and the balance is Fe.

[0057] The production technology of the 830MPa level high-strength hot-rolled steel bar of the present embodiment is carried out according to the following steps:

[0058] (1) Put the smelted steel bar into the heating furnace and heat it to 1010°C, then quickly cool the steel bar to 660°C through the first online cooling process, and then quench it with water or quenching liquid in the quenching device for 17 seconds, and then pass through The tempering heating furnace is heated to 520°C for tempering, and then cooled to normal temperature through the second cooling process;

[0059] The first cooling process: use water cooling to cool the steel bars to 660°C at a cooling rate of 11°C / s;

[0060] The second cooling process: the combin...

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Abstract

The invention relates to a reinforcement bar and a production technology thereof, in particular to a high-strength hot-rolled reinforcement bar of the 830 MPa level, and a production technology of the reinforcement bar. The reinforcement bar comprises the following chemical components by weight: 0.38 to 0.43% of C, 0.7 to 0.9% of Cr, 0.6 to 0.8% of Mn, 0.15 to 0.25% of Mo, 0.2 to 0.3% of Si, 1.6 to 2% of Ni, 0.035% of S, 0.035% of P, 0.035% of N and the balance of Fe. The shear strength of the reinforcement bar can reach 830 MPa; the reinforcement bar has the advantages of high strength, good ductility, high lagging and fracture resistance, economy of steel material, underrelaxation, easiness in welding, high upset performance and the like, can enable carbide to dissolve fully and diffuse uniformly, and avoids that intercrystalline corrosion and pitting exceeding are caused due to intercrystalline separation of carbide.

Description

technical field [0001] The invention relates to a steel bar and a production process thereof, in particular to an 830MPa grade high-strength hot-rolled steel bar and a production process thereof. Background technique [0002] Hot-rolled steel bars are finished steel bars that have been hot-rolled and naturally cooled. They are made of low-carbon steel and ordinary alloy steel at high temperatures. They are mainly used for reinforcement of reinforced concrete and prestressed concrete structures. They are used in civil engineering One of the most widely used steel varieties. Hot-rolled steel bars are graded according to the standard value of yield strength and are divided into four grades: [0003] HPB235 (Q235), the standard value of the yield strength of the steel bar is 235MPa, the diameter is 8-20mm, and the elastic modulus is 210GPa. [0004] HRB335 (20MnSi), the standard value of the yield strength of the steel bar is 335MPa, the diameter is 6-50mm, and the elastic mod...

Claims

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Application Information

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IPC IPC(8): C22C38/44C21D8/08
Inventor 姚圣法吴海洋
Owner 江苏森林建筑新材料股份有限公司
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