MENU

/
/
Analysis of the welding heat affected zone of the used roll forming machine

Analysis of the welding heat affected zone of the used roll forming machine

  • Sort:Information
  • Auth:
  • Source:
  • Release time:2022-07-09 11:30
  • Pvs:

【概要描述】When the used roll forming machine is used to make pipes, a complete high-frequency weld will appear, and the formation of a complete high-frequency weld is composed of two areas, the fusion zone and the heat-affected zone.

Analysis of the welding heat affected zone of the used roll forming machine

【概要描述】When the used roll forming machine is used to make pipes, a complete high-frequency weld will appear, and the formation of a complete high-frequency weld is composed of two areas, the fusion zone and the heat-affected zone.

  • Sort:Information
  • Auth:
  • Source:
  • Release time:2022-07-09 11:30
  • Pvs:
Detail

When the used roll forming machine is used to make pipes, a complete high-frequency weld will appear, and the formation of a complete high-frequency weld is composed of two areas, the fusion zone and the heat-affected zone. The fusion zone is a narrow weld. Welding theory and practice point out that the quality of welding depends not only on the weld, but also on the welding heat-affected zone; sometimes there are more problems in the heat-affected zone than the weld, which is more complicated. It is especially obvious when the strength of alloy steel pipe is used. Therefore, it is of great significance to study the changes in the structure and properties of the heat-affected zone tube blank for the strength of the weld and the quality of the welded pipe.

 

The structure and morphology of the welding heat-affected zone is closely related to the carbon equivalent of the steel. The welding heat-affected zone of the used roll forming machine belongs to the low-carbon equivalent category. Crystallization zone, recrystallization zone and aging embrittlement zone.

 

Used roll forming machine

 

(1) Overheating zone. The temperature is between 1400 and 1100 °C, and the closer to the fusion zone (weld), the higher the temperature; it is manifested that some refractory points such as carbides and oxides dissolve into austenite at the solidus, and austenite grains thick. Coarse austenite is easy to form superheated Widmanite structure during cooling, resulting in reduced toughness.

 

(2) Phase change recrystallization zone. The temperature is between 1100~850°C, above the Ac3 line; the recrystallization phase transition occurs when heated, so that the grains are refined; it is equivalent to the normalized structure of low-carbon steel, and has good comprehensive mechanical properties.

 

(3) Incomplete recrystallization zone. When the temperature is between 850 and 700 °C, only part of the metal in this region undergoes recrystallization phase transformation; it is the coexistence and mixing of the original ferrite coarse grain and fine grain region, and the mechanical properties are poor.

 

(4) Recrystallization zone. When the temperature is between 700 and 500°C, the internal structure of the metal does not change after heating, only the shape of the grain changes; it is an equiaxed ferrite grain, the strength and hardness are lower than that of the base metal, and the plasticity and toughness are improved. is the softening zone of the weld.

 

(5)Aging embrittlement zone. When the temperature is between 500 and room temperature, the metal structure is close to the base metal; the longer the placement time, the closer the structure and properties are to the base metal.

 

Through the analysis of the welding heat affected zone of the used roll forming machine, not only can the welding process be better improved, but also it is helpful to understand the formation and distribution of welding stress on the welded pipe.

 

关键词:

More News

Analyzing the roll life of a used ERW tube mill
Analyzing the roll life of a used ERW tube mill
In the production of used ERW tube mills, the roll is the key and important special tool. Roll consumption is also a key tool for manipulating product costs. In addition, the normal operation of the roll will directly affect the output and quality of welded pipe manufacturing. Therefore, welded pipe manufacturers attach great importance to and strive to improve the service life of the roll.
Detail
In the production of used ERW tube mills, the roll is the key and important special tool. Roll consumption is also a key tool for manipulating product costs. In addition, the normal operation of the roll will directly affect the output and quality of welded pipe manufacturing. Therefore, welded pipe manufacturers attach great importance to and strive to improve the service life of the roll.
How to extend the service life of high frequency welded pipe equipment
How to extend the service life of high frequency welded pipe equipment
The service life of high frequency welded pipe equipment is of concern to everyone. The contribution made in the welding industry is immeasurable, and the care of it by customers should be paid more attention. So how can the service life of high frequency welded pipe equipment be extended in the actual production process?
Detail
The service life of high frequency welded pipe equipment is of concern to everyone. The contribution made in the welding industry is immeasurable, and the care of it by customers should be paid more attention. So how can the service life of high frequency welded pipe equipment be extended in the actual production process?
Adjusting the welding seam position of square and rectangular pipes made by directly forming to square pipe mill (2)
Adjusting the welding seam position of square and rectangular pipes made by directly forming to square pipe mill (2)
Judging that the quality of the square tube produced by the directly forming to square pipe mill meets the standard is based on a large number of inspection data of the microhardness of the weld and the microhardness of the base material. The former is much higher than the latter. It is for this reason that the weld is usually not placed at a positive angle, but placed within t~(t+5mm) from the corner edge to reduce the risk of weld cracks. This requires effective control of the weld position. Control methods include forming roll method, guide roll method and sizing roll method.
Detail
Judging that the quality of the square tube produced by the directly forming to square pipe mill meets the standard is based on a large number of inspection data of the microhardness of the weld and the microhardness of the base material. The former is much higher than the latter. It is for this reason that the weld is usually not placed at a positive angle, but placed within t~(t+5mm) from the corner edge to reduce the risk of weld cracks. This requires effective control of the weld position. Control methods include forming roll method, guide roll method and sizing roll method.
Welding and rolling bottom line and sizing rolling bottom line in high frequency welded pipe machine
Welding and rolling bottom line and sizing rolling bottom line in high frequency welded pipe machine
The rolling line of high frequency welded pipe machine is all rolls on the welded pipe unit, including leveling rolls, forming flat rolls, guide rolls, squeeze rolls, deburring idlers, calendering rolls, sizing rolls, straightening rolls and other rolls. It is also the reference line for the installation and adjustment of related auxiliary equipment such as uncoilers, spiral loopers, flying saws, conveyor rollers, etc. It is the general term for the rolling bottom line and rolling center line, just like the human body. The spine plays a pivotal role in all process parameters of welded pipe production.
Detail
The rolling line of high frequency welded pipe machine is all rolls on the welded pipe unit, including leveling rolls, forming flat rolls, guide rolls, squeeze rolls, deburring idlers, calendering rolls, sizing rolls, straightening rolls and other rolls. It is also the reference line for the installation and adjustment of related auxiliary equipment such as uncoilers, spiral loopers, flying saws, conveyor rollers, etc. It is the general term for the rolling bottom line and rolling center line, just like the human body. The spine plays a pivotal role in all process parameters of welded pipe production.
Contact information
Tel: +86-13392281699
Wechat: 13392281699
Email: zty@usedpipemill.com
Company address:No. A99, East Lecong Avenue, Lecong Town, Foshan City, Guangdong Province

Recommendation

Online Inquiry

留言应用名称:
底部留言
描述:

LINK

Contact Us

Tel (wechat): 13336487288
Wechat:+86 13336487288

WhatsApp:+86 13336487288
Email: zty@usedpipemill.com

Address: No. A99, Lecong Avenue East, Lecong Town, Foshan City, Guangdong Province

QRCODE

Copyright 0 2021 jinyujie. 粤ICP备13051810号 Powerby:  300.cn