Unlock instant, AI-driven research and patent intelligence for your innovation.

A kind of threaded steel bar for 960mpa high-strength prestressed structure and its preparation method

A technology of prestressed structure and threaded steel bar, applied in the field of metal material processing, can solve the problem of high production cost, and achieve the effects of increased strength, good prestress relaxation, and slow hardness change

Active Publication Date: 2016-05-11
WUKUN STEEL
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to different process technologies, there are great differences in the strengthening effect of microalloying elements V, Ti, and Nb. Conventional microalloying strengthening technology + controlled cooling process produces finish-rolled rebar, and a large number of microalloying elements are added, which makes the production cost higher.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A kind of threaded steel bar for 960mpa high-strength prestressed structure and its preparation method
  • A kind of threaded steel bar for 960mpa high-strength prestressed structure and its preparation method
  • A kind of threaded steel bar for 960mpa high-strength prestressed structure and its preparation method

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0017] The preparation method of the 960MPa level high-strength prestressed structure threaded steel bar of the present invention comprises steel billet preparation, rolling, post-processing steps, specifically comprises:

[0018] A. Billet preparation:

[0019] 1) Melt iron converter smelting: chemical composition C4.0~4.5wt%, Si0.25~0.50wt%, Mn0.25~0.50wt%, P0.080~0.120wt%, S≤0.025wt%, the rest is Fe and unavoidable impurities of molten iron, chemical composition C0.20~0.30wt%, Si0.25~0.60wt%, Mn1.15~1.65wt%, P0.025~0.045wt%, S0.020~0.045wt% %, the rest is Fe and unavoidable impurities of steel scrap and chemical composition C3.2~3.6wt%, Si0.30~0.60wt%, Mn0.30~0.55wt%, P0.060~0.090wt%, S0 .020~0.035wt%, the rest is Fe and unavoidable impurities, and the pig iron is added to the LD converter for top-bottom compound blowing, and lime, dolomite, magnesite balls are added to make slag, and the amount of lime added is 30~40kg / t steel, the amount of dolomite added is 15~20kg / t ...

Embodiment 1

[0045] A, molten iron converter smelting: molten iron (chemical composition C4.0wt%, Si0.25wt%, Mn0.25wt%, P0.080wt%, S0.020wt%, the rest is Fe and unavoidable impurities), steel scrap ( Chemical composition C0.20wt%, Si0.25wt%, Mn1.15wt%, P0.025wt%, S0.020wt%, the rest is Fe and unavoidable impurities) and pig iron (chemical composition C3.2wt%, Si0. 30wt%, Mn0.30wt%, P0.060wt%, S0.020wt%, and the rest are Fe and unavoidable impurities) into the LD converter for conventional top-bottom compound blowing, adding conventional lime, dolomite, diamond Magnesium ball slagging, the addition of lime is 30kg / t of steel, the addition of dolomite is 15kg / t of steel, the addition of magnesite balls is 4.0kg / t of steel, the carbon content of the control end point is 0.10wt%, and the tapping temperature is 1620°C ; Before tapping, active lime is added to the bottom of the ladle for slag washing. The amount of lime added is 2.0kg / t steel.

[0046] B. Deoxidation and alloying of molten stee...

Embodiment 2

[0060] A, molten iron converter smelting: molten iron (chemical composition C4.2wt%, Si0.40wt%, Mn0.40wt%, P0.100wt%, S0.023wt%, the rest is Fe and unavoidable impurities), steel scrap ( Chemical composition C0.25wt%, Si0.45wt%, Mn1.40wt%, P0.035wt%, S0.035wt%, the rest is Fe and unavoidable impurities) and pig iron (chemical composition

[0061] C3.4wt%, Si0.45wt%, Mn0.45wt%, P0.075wt%, S0.028wt%, the rest are Fe and unavoidable impurities) into the LD converter for conventional top-bottom composite blowing, adding Conventional lime, dolomite, and magnesite balls are used to make slag, the amount of lime added is 36kg / t steel, the amount of dolomite added is 18kg / t steel, the amount of magnesite balls added is 5.0kg / t steel, and the carbon content at the control end point is 0.12wt% , The tapping temperature is 1630°C; before tapping, active lime is added to the bottom of the ladle for slag washing. The amount of lime added is 2.0kg / t steel.

[0062] B. Deoxidation and alloy...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a 960MPa high-strength twisted steel bar for prestressed structures and a preparation method thereof. The 960MPa high-strength twisted steel bar for prestressed structures comprises the following components in percentage by weight: 0.35-0.40% of C, 1.00-1.20% of Si, 1.10-1.30% of Mn, 0.20-0.40% of Cr, 0.080-0.110% of V, 0.020-0.040% of Mo, 0.010-0.020% of Nb, 0.001-0.020% of S, 0.001-0.025% of P, and the balance of Fe and inevitable impurities. The method comprises the following steps: steel billet preparation, rolling and after-treatment. On the premise of ensuring certain carbon content, alloy elements Mo and V capable of enhancing hardenability of steel are added, and controlled rolling and cooling techniques are adopted to refine the austenite grains, thereby generating precipitation strength. The steel structure grains are obviously refined, thereby reducing the network ferrite structure at the steel core. The steel has the advantages of high strength, slow variation in hardness, stable mechanical properties and favorable prestress looseness.

Description

technical field [0001] The invention belongs to the technical field of metal material processing, and in particular relates to a threaded steel bar for 960MPa high-strength prestressed structures and a preparation method thereof. Background technique [0002] High-strength finish-rolled threaded steel bars for prestressed structures are referred to as finish-rolled threaded steel bars, which have the advantages of high strength, convenient and reliable connection, tensioning, and anchoring, no need for cold drawing and welding during construction, and simple construction. Finish-rolled rebar is widely used in continuous beams and large-scale frame structures of large-scale water conservancy, industrial and civil buildings, large and medium-span bridges for highways and railways, prestressed concrete structures such as nuclear power plants, and geotechnical anchorage projects. [0003] There is currently no uniform composition requirement for the chemical composition of finis...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/26C22C33/06C21D8/08
CPCC21D8/08C22C33/06C22C38/02C22C38/04C22C38/18C22C38/22C22C38/24C22C38/26
Inventor 张瑜陈伟王洁李金柱张志波冯再武房业坤曹云赵卫东张红斌毛宁锰
Owner WUKUN STEEL