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

Heat treatment process for weather-resistant steel high-strength bolt connection pair

A technology of high-strength bolts and processing technology, which is applied in the field of heat treatment to achieve excellent anti-corrosion effects and high strength

Inactive Publication Date: 2019-05-21
RAILWAY ENG RES INST CHINA ACADEMY OF RAILWAY SCI +2
View PDF3 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, my country is still in a blind spot for weather-resistant steel bolts, and there is no suitable reference standard for reasonable standardization, let alone the heat treatment process that directly affects product performance, coupled with the large demand and urgency of the domestic construction industry for it The development of weathering steel bolts is already a plan that has to be mentioned

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] A secondary heat treatment process for weather-resistant steel high-strength bolt connections, comprising the following steps

[0024] S1: Bolt connection pair pretreatment; specifically, including dephosphorization: put the product into the washing machine, and pour the cleaning solution until the product is completely immersed in the cleaning solution, adjust the cleaning temperature to 40°C, and stir once every 15 minutes. After cleaning for 2 hours, the product is taken out and placed in a dephosphorization tank for dephosphorization treatment.

[0025] The cleaning solution is composed of the following components in parts by mass: 20 parts of butyl acetate, 10 parts of polyglycolic acid, 16 parts of aminoacetic acid, 13 parts of ethyl acrylate, 5 parts of oleic acid triethanolamine salt, 3 parts of ethanolamine and 18 parts of water; The dephosphorization tank is equipped with a dephosphorization solution, and the dephosphorization solution is a potassium hydroxide...

Embodiment 2

[0034] A secondary heat treatment process for weather-resistant steel high-strength bolt connections, comprising the following steps

[0035] S1: Bolt connection pair pretreatment; specifically, including dephosphorization: put the product into the washing machine, and pour the cleaning solution until the product is completely immersed in the cleaning solution, adjust the cleaning temperature to 40°C, and stir once every 15 minutes. After cleaning for 2 hours, the product is taken out and placed in a dephosphorization tank for dephosphorization treatment.

[0036] The cleaning solution is composed of the following components in parts by mass: 20 parts of butyl acetate, 10 parts of polyglycolic acid, 16 parts of aminoacetic acid, 13 parts of ethyl acrylate, 5 parts of oleic acid triethanolamine salt, 3 parts of ethanolamine and 18 parts of water; The dephosphorization tank is equipped with a dephosphorization solution, and the dephosphorization solution is a potassium hydroxide...

Embodiment 3

[0044] A secondary heat treatment process for weather-resistant steel high-strength bolt connections, comprising the following steps

[0045] S1: Bolt connection pair pretreatment; specifically, including dephosphorization: put the product into the washing machine, and pour the cleaning solution until the product is completely immersed in the cleaning solution, adjust the cleaning temperature to 40°C, and stir once every 15 minutes. After cleaning for 2 hours, the product is taken out and placed in a dephosphorization tank for dephosphorization treatment.

[0046] The cleaning solution is composed of the following components in parts by mass: 20 parts of butyl acetate, 10 parts of polyglycolic acid, 16 parts of aminoacetic acid, 13 parts of ethyl acrylate, 5 parts of oleic acid triethanolamine salt, 3 parts of ethanolamine and 18 parts of water; The dephosphorization tank is equipped with a dephosphorization solution, and the dephosphorization solution is a potassium hydroxide...

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

PropertyMeasurementUnit
Impact energyaaaaaaaaaa
Impact energyaaaaaaaaaa
Login to View More

Abstract

The invention discloses a heat treatment process for a weather-resistant steel high-strength bolt connection pair. The heat treatment process for the weather-resistant steel high-strength bolt connection pair comprises the following steps: S1, carrying out pretreatment on the bolt connection pair; S2, carrying out quenching treatment on the pretreated bolt connection pair for a quenching time of 55-65min at a quenching temperature of 790-870 DEG C; S3, carrying out tempering treatment on the bolt connection pair after being quenched for a tempering time of 110-130min at a tempering temperatureof 500-530 DEG C; and S4, obtaining a finished product after the heat treatment is concluded, wherein the step S2 comprises placing the bolt connection pair in a quenching furnace, and charging methanol into the quenching furnace; then slowly increasing the temperature of the quenching furnace to 790-810 DEG C, and keeping for 8-12min; continuing to heat to reach 820-840 DEG C, and keeping for 8-12min; continuing to heat to reach 870-890 DEG C, and insulating heat for 25-35min; and cooling to reach 865-875 DEG C, and keeping for 8-12min. The bolt connection pair treated through the heat treatment process is excellent in anti-corrosion effect and high in strength; and the weather-resistant coefficient reaches 6.95 and above, the ductility reaches 13% and above, the percentage reduction ofarea reaches 50% and above, and the impact energy at minus 20 DEG C reaches 41J and above.

Description

technical field [0001] The invention belongs to the technical field of heat treatment, and in particular relates to a secondary heat treatment process for high-strength bolt connections of weathering steel. Background technique [0002] Atmospheric corrosion is one of the main forms of failure of building bolts. According to foreign statistics, nearly 20% of the accidents in which building bolts break are caused by corrosion. The corrosion of building bolts not only brings damage to the structure, but also the periodic painting will consume huge manpower and material resources, causing a lot of pollution to the environment, and also adding a heavy management and maintenance burden to the public works department. [0003] The most prominent advantage of weathering steel material is corrosion resistance. After forming a certain ratio of alloying elements such as CU and NI contained in it, it will form an effective oxide layer on the surface of the part during the corrosion pro...

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
IPC IPC(8): C21D1/18C21D9/00
Inventor 刘晓光陶晓燕沈家华苏永华欧元程曾进凯林泓斌张军
Owner RAILWAY ENG RES INST CHINA ACADEMY OF RAILWAY SCI