MENU

/
/
The significance of studying the heat affected zone of the used roll forming machine welding

The significance of studying the heat affected zone of the used roll forming machine welding

  • Sort:Information
  • Auth:
  • Source:
  • Release time:2022-05-05 11:30
  • Pvs:

【概要描述】When used roll forming machine is used to manufacture a welded pipe, a complete high-frequency welded pipe weld will appear, which is composed of a fusion zone and a heat-affected zone. The fusion zone is a narrow weld.

The significance of studying the heat affected zone of the used roll forming machine welding

【概要描述】When used roll forming machine is used to manufacture a welded pipe, a complete high-frequency welded pipe weld will appear, which is composed of a fusion zone and a heat-affected zone. The fusion zone is a narrow weld.

  • Sort:Information
  • Auth:
  • Source:
  • Release time:2022-05-05 11:30
  • Pvs:
Detail

When used roll forming machine is used to manufacture a welded pipe, a complete high-frequency welded pipe weld will appear, which is composed of a fusion zone and a 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 the problems in the heat-affected zone are more complex than the weld. It is especially obvious when it comes to steel pipes. Many cases of failed oil pipes and high-strength alloy steel pipes have proved that the problem is often in the heat affected zone. Therefore, it is of great significance to study the changes in the structure and properties of the tube blank that are affected by the heat of the used roll forming machine, which is of great significance to the strength of the welded seam and the quality of the welded tube.

 

Used roll forming machine

 

Used roll forming machine

 

Microstructure of heat affected zone of low carbon equivalent 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. Overheating zone, Phase change recrystallization zone,Incomplete recrystallization zone, recrystallization zone and aging embrittlement zone.

 

(1) Overheating zone

The temperature is between 1400 and 1100 °C, and the closer it is to the fusion zone, the higher the temperature; it is manifested that some refractory points such as carbides and oxides melt into austenite at the solidus, and the austenite grains are coarse. 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 (P+F transforms into A, and A transforms into P+F during cooling), so that the grains are refined; equivalent to low carbon The normalized structure of steel 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°C and room temperature, the metal structure is close to the base metal; the longer the storage time, the closer the structure and properties are to the base metal.

 

Through the analysis of the structure 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

Welded pipe straightening method of used welded pipe machines
Welded pipe straightening method of used welded pipe machines
The problem of straightening the welded pipe often occurs when the used welded pipe machines is used to make pipes. For the straightening of welded pipes, we will explain to you how to make the pipes straightened by used welded pipe machines. Pay attention to the following requirements.
Detail
The problem of straightening the welded pipe often occurs when the used welded pipe machines is used to make pipes. For the straightening of welded pipes, we will explain to you how to make the pipes straightened by used welded pipe machines. Pay attention to the following requirements.
Common faults of used welded pipe units
Common faults of used welded pipe units
There are relatively many failures of used welded pipe machines, and the causes of failures are also more complicated. Often, one result is caused by multiple reasons, or one cause can cause several results. Some failures are tricky to deal with. Let's start with a brief description of the scratch accident.
Detail
There are relatively many failures of used welded pipe machines, and the causes of failures are also more complicated. Often, one result is caused by multiple reasons, or one cause can cause several results. Some failures are tricky to deal with. Let's start with a brief description of the scratch accident.
Common faults of used welded pipe mills production line forming machines (5)
Common faults of used welded pipe mills production line forming machines (5)
Common faults of used welded pipe mills production line forming machines can be divided into ① deviation ② scratches ③ "indenter" phenomenon ④ "drill belt" phenomenon. In order to let everyone understand the common faults of the molding machine in detail, we will introduce ③ "indenter" phenomenon.
Detail
Common faults of used welded pipe mills production line forming machines can be divided into ① deviation ② scratches ③ "indenter" phenomenon ④ "drill belt" phenomenon. In order to let everyone understand the common faults of the molding machine in detail, we will introduce ③ "indenter" phenomenon.
Common faults of used welded pipe mills production line forming machines (4)
Common faults of used welded pipe mills production line forming machines (4)
Common faults of used welded pipe mills production line forming machines can be divided into ① deviation. ② scratches. ③ "indenter" phenomenon. ④ "drill belt" phenomenon. In order to let everyone understand the common faults of the molding machine in detail, we will introduce ② scratches.
Detail
Common faults of used welded pipe mills production line forming machines can be divided into ① deviation. ② scratches. ③ "indenter" phenomenon. ④ "drill belt" phenomenon. In order to let everyone understand the common faults of the molding machine in detail, we will introduce ② scratches.
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