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

Weather-proof cold heading steel wire rod for 800MPa-grade fastener and production method thereof

A production method, 800mpa technology, applied in the direction of metal rolling, etc., can solve the problems of material processing performance deterioration, increase the difficulty of materials, limit the scope of use of materials, etc.

Active Publication Date: 2019-07-02
ANGANG STEEL CO LTD
View PDF9 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage is that the material provided by this invention can meet the strength requirements of 8.8 grade bolts and supporting nuts, but compared with ordinary 8.8 grade cold heading steel wire rods, the content of C and Si has been greatly increased, resulting in material The deterioration of processability, so the processability must be improved by the heat treatment process described in the invention
In addition, the invention adds a large amount of precious metals and rare earth elements, which will greatly increase the production cost of materials, increase the difficulty of material promotion, and limit the use range of materials

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
  • Weather-proof cold heading steel wire rod for 800MPa-grade fastener and production method thereof
  • Weather-proof cold heading steel wire rod for 800MPa-grade fastener and production method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Smelting is carried out according to the chemical composition of the 800MPa weather-resistant cold heading steel wire rod of the present invention, the refining time is 35 minutes, the flow rate of argon gas is 200NL / min, the time of argon blowing is 30 minutes, and after standing for 25 minutes, it is poured into a section size of 280 *For a 380mm bloom, the degree of superheat is 27°C, the current intensity of electromagnetic stirring in the mold is 500A, and the current intensity of electromagnetic stirring at the end of solidification is 500A. The 280*380mm bloom is heated and rolled into a steel billet with a section size of 155*155mm, and then the steel billet is inspected and the surface defect position is ground. Then use qualified steel billet to roll in high speed wire rod mill For wire rod, the rolling process is as follows: heat the billet to 1075°C, keep it warm for 110 minutes, and the temperature difference of the passing rod is 26°C; control the rolling...

Embodiment 2

[0041] According to the chemical composition of the 800MPa weather-resistant cold heading steel wire rod in the present invention, the refining time is 40 minutes, the flow rate of argon gas is 220NL / min, the time of argon blowing is 35 minutes, and after standing for 30 minutes, it is poured into a section size of 280 *For a 380mm bloom, the degree of superheat is 28°C, the current intensity of electromagnetic stirring in the mold is 450A, and the current intensity of electromagnetic stirring at the solidification end is 550A. The 280*380mm bloom is heated and rolled into a steel billet with a section size of 155*155mm, and then the steel billet is inspected and the surface defect position is ground. Then use qualified steel billet to roll in high speed wire rod mill Wire rod, the rolling process is as follows: heat the billet to 1050°C, keep it warm for 120 minutes, and the temperature difference of the passing rod is 25°C; control the rolling start temperature to 980°C, th...

Embodiment 3

[0043] Smelting is carried out according to the chemical composition of the 800MPa grade weather-resistant cold heading steel wire rod described in the present invention, the refining time is 40 minutes, the argon gas flow rate is 190NL / min, the argon blowing time is 30 minutes, and after standing for 40 minutes, it is poured into a section size of 280 *For a 380mm bloom, the degree of superheat is 28°C, the current intensity of electromagnetic stirring in the mold is 500A, and the current intensity of electromagnetic stirring at the end of solidification is 550A. The 280*380mm bloom is heated and rolled into a steel billet with a section size of 155*155mm, and then the steel billet is inspected and the surface defect position is ground. Then use qualified steel billet to roll in high speed wire rod mill For wire rod, the rolling process is as follows: heat the billet to 1100°C, keep it warm for 120 minutes, and the temperature difference of the passing rod is 25°C; control t...

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 provides a weather-proof cold heading steel wire rod for a 800MPa-grade fastener and a production method thereof. The steel wire rod comprises the following components in percentage by weight: 0.15%-0.30% of C, 0.10%-0.40% of Si, 0.80%-1.20% of Mn, smaller than or equal to 0.035% of P, smaller than or equal to 0.040% of S, 0.30%-0.70% of Cr, 0.25%-0.55% of Ni, 0.15%-0.40% of Cu, 0.02%-0.10% of V and the balance Fe and inevitable impurity elements. The production method comprises the steps of molten iron pretreatment, converter smelting, LF furnace refining, VD, square billet continuous casting, square billet continuous rolling, steel billet cleaning, heating, rolling, controlled cooling and finishing. Various properties of an 800MPa-grade weather-proof connecting pair manufactured by adopting the cold heading steel wire rod provided by the invention meet the standard requirements. The corrosion rate of the steel wire rod in the accelerated corrosion test is lower than 1 / 3 of that of common cold heading steel.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to a weather-resistant cold-heading steel wire rod for 800MPa-level fasteners and a production method thereof. Background technique [0002] Compared with reinforced concrete structures, steel structures are gradually being used more widely due to their advantages such as easy assembly, recyclability, and environmental friendliness. In addition to traditional transmission towers and wind power towers, steel structures are also increasingly used in bridges. At present, in European and American countries, steel structure bridges account for more than 90% of new bridges. However, steel structures need to face an important problem—corrosion. For ordinary structural steel, due to the loose structure of its surface corrosion products, corrosion can continue to advance along the interface between the corrosion layer and the substrate to the interior of the substrate, th...

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 Applications(China)
IPC IPC(8): C22C38/42C22C38/46C22C38/02C22C38/04C22C33/04B21B1/46
CPCB21B1/46C22C33/04C22C38/02C22C38/04C22C38/42C22C38/46
Inventor 高航郭大勇车安常宏伟杨辉张博马立国王秉喜王宏亮李琳
Owner ANGANG STEEL CO LTD