Used welded pipe production line, the influence of heat-affected zone control technology on welding quality
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- Release time:2022-01-11 11:30
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【概要描述】In the used welded pipe production line, high-frequency welding steps will appear, and the quality of high-frequency welding is often affected by the heat-affected zone control technology. For the quality of steel pipe welding, it is necessary to understand the heat-affected zone control technology of the second-hand welded pipe production line.
Used welded pipe production line, the influence of heat-affected zone control technology on welding quality
【概要描述】In the used welded pipe production line, high-frequency welding steps will appear, and the quality of high-frequency welding is often affected by the heat-affected zone control technology. For the quality of steel pipe welding, it is necessary to understand the heat-affected zone control technology of the second-hand welded pipe production line.
- Sort:Information
- Auth:
- Source:
- Release time:2022-01-11 11:30
- Pvs:
In the used welded pipe production line, high-frequency welding steps will appear, and the quality of high-frequency welding is often affected by the heat-affected zone control technology. For the quality of steel pipe welding, it is necessary to understand the heat-affected zone control technology of the used welded pipe production line.
The metallurgical definition of high-frequency welding heat-affected zone is:
The change area of the structure and properties of the base metal near the weld caused by welding is caused by the temperature change of the welding process and the subsequent cooling process. Different weld structures and base metals have different hardness and toughness, for example, the properties of different parts of the weld area are different. The temperature distribution of the welding V-shaped zone directly affects the structure and grain size of the weld metal, which will significantly affect the experimental results of the material.
Welding temperature changes cause changes in the structure of the weld. The specimens made by cutting and polishing can be observed under a microscope. The structure of the heat-affected zone of the weld profile has obvious changes.
The influencing factors of the heat-affected zone in the used welded pipe production line are many, including:
(1) Plate, diameter and wall thickness of steel pipe;
(2) Unit operating speed and welding power;
(3) Whether to use induction welding or contact welding and welding the length of the V-shaped zone;
(4) The forming quality of the strip edge when passing through the weld;
(5) The design of the welding position and the squeezing force applied by the welding point.
We can pre-set the pipe diameter, wall thickness and pipe material and other parameters before operation. Parameters such as welding power, welding frequency, V-shaped zone length and welding speed are all flexibly set.
By selecting these parameters correctly, a heat-affected zone with good performance can be obtained, thereby ensuring the quality and performance of the steel pipe.
It is very important that the width of the heat-affected zone is not "symmetrical" with the best width, and it is the best measure.
So far, the main properties of high-frequency welds can be inferred from the heat-affected zone, and the structure and performance of the heat-affected zone can be judged based on the welding time-temperature change. Therefore, in order to study the characteristics of the heat-affected zone, it is necessary to understand the law of the influence of unit adjustment on the temperature distribution of the edge of the welded V-shaped zone.
Theoretically, the temperature distribution of the high-frequency welding V-shaped zone is firstly determined by the heat generated by the current flowing through the V-shaped zone. The heat conduction determines the penetration depth of the steel strip edge of the welding zone. The characteristics of the high-frequency current distribution are to look at it. The penetration depth is a function of the welding frequency. The characteristic of the heat conduction process is that the depth of heat penetration is a function of the length of the V-shaped zone and the welding speed.
The actual state of high-frequency welding of steel pipes is:
①The current penetration depth is greater than the thermal penetration depth, which is a result of temperature distribution; ②The thermal penetration depth is greater than the current penetration depth, which is the result of another temperature distribution; ③The thermal penetration depth, which is a transition Temperature distribution status.
In short, establish a time-temperature curve in the welding heat-affected zone of the used welded pipe production line, and combine the high-frequency current heat effect (current penetration depth) and the heat conduction in the welding V-shaped zone (heat penetration depth) to control the temperature distribution in the welding zone. If the current penetration depth and heat penetration depth can be calculated based on some important welded pipe unit parameters (pipe diameter, wall thickness, welding power, welding frequency, V-shaped zone length and pipe performance), then the steel strip edge of the welded V-shaped zone can be predicted This method can accurately predict and control the heat-affected zone of the weld.
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Time of issue : 2025-02-11
1. The characteristics of high-precision steel pipe
High dimensional accuracy: small outer diameter, wall thickness tolerance (usually up to ±0.05mm), low ellipticity.
Excellent surface quality: smooth weld without burrs, surface finish Ra≤0.8μm.
Stable mechanical properties: weld strength close to the base material, uniform compressive/tensile properties.
Applicable materials: stainless steel (304/316L), carbon steel, alloy steel (such as API series), etc.
2. Core production process
(1) Type of pipe welding machine
High-frequency welding (HFW) : high efficiency, suitable for medium thin wall pipe (Φ10~Φ600mm), need to cooperate with precision forming unit.
Laser welding: small heat affected zone, narrow weld (0.1~0.3mm), suitable for ultra-thin walls (such as 0.3mm) or special alloys.
TIG welding: For high alloy steel or thick wall pipe, higher weld purity.
(2) Key process links
Forming process: multi-roll continuous cold forming, dynamic adjustment of roll parameters to compensate for rebound.
Welding control:
High frequency welding: precise control of current frequency (100~400kHz) and extrusion amount.
Laser welding: focus position accuracy ±0.05mm, real-time depth monitoring (such as CCD vision).
Online detection:
Eddy current inspection (ET) : Detection of surface cracks.
Ultrasonic inspection (UT) : detection of internal defects (sensitivity Φ0.5mm equivalent flat hole).
Laser caliper: Outer diameter closed loop control (accuracy ±0.01mm).
3. Post-processing technology
Heat treatment: bright annealing (hydrogen nitrogen protection atmosphere) to eliminate stress, hardness fluctuation ≤3HRC.
Straightening: multi-roll precision straightening, straightness ≤0.5mm/m.
Surface treatment:
Electrolytic polishing (EP) : For medical/food grade stainless steel tubes, Ra up to 0.2μm.
Coating: hot dip galvanizing (zinc layer ≥80μm) or electroless nickel plating (uniform thickness ±2μm).
4. Typical application areas
Automobile manufacturing: fuel injection pipe (tolerance ±0.03mm), hydraulic pipe.
Semiconductor equipment: Ultra-high clean gas delivery pipe (inner wall EP treatment, particle ≤Class 5).
Medical instruments: endoscopic catheter (Φ1~5mm, wall thickness 0.1mm).
Energy industry: Instrument tubes for nuclear power plants (SA213-TP347H material, intergranular corrosion test passed).
5. Quality control standards
International standard:
ASTM A269 (Universal Seamless and Welded Austenitic Stainless Steel Pipe)
EN 10305-4 (Precision welded pipes for hydraulic systems)
Industry certification: ISO 9001, PED 2014/68/EU (Pressure Equipment Directive).
6. Technological trends
Intelligent production: AI algorithm optimizes welding parameters, and the yield is increased to more than 99.5%.
Composite process: laser + arc composite welding, both efficiency and quality (speed increased by 30%).
Green manufacturing: low energy high frequency power supply (efficiency ≥90%), waste acid recovery ≥95%.
Through the above process optimization and strict quality control, the high-precision steel pipe produced by the pipe welding machine can meet the demanding requirements of size, performance and reliability in high-end industrial fields. In actual production, the process route needs to be customized according to the material characteristics and uses, for example, medical tubes need to undergo additional passivation treatment and biocompatibility testing.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill
1. The characteristics of high-precision steel pipe
High dimensional accuracy: small outer diameter, wall thickness tolerance (usually up to ±0.05mm), low ellipticity.
Excellent surface quality: smooth weld without burrs, surface finish Ra≤0.8μm.
Stable mechanical properties: weld strength close to the base material, uniform compressive/tensile properties.
Applicable materials: stainless steel (304/316L), carbon steel, alloy steel (such as API series), etc.
2. Core production process
(1) Type of pipe welding machine
High-frequency welding (HFW) : high efficiency, suitable for medium thin wall pipe (Φ10~Φ600mm), need to cooperate with precision forming unit.
Laser welding: small heat affected zone, narrow weld (0.1~0.3mm), suitable for ultra-thin walls (such as 0.3mm) or special alloys.
TIG welding: For high alloy steel or thick wall pipe, higher weld purity.
(2) Key process links
Forming process: multi-roll continuous cold forming, dynamic adjustment of roll parameters to compensate for rebound.
Welding control:
High frequency welding: precise control of current frequency (100~400kHz) and extrusion amount.
Laser welding: focus position accuracy ±0.05mm, real-time depth monitoring (such as CCD vision).
Online detection:
Eddy current inspection (ET) : Detection of surface cracks.
Ultrasonic inspection (UT) : detection of internal defects (sensitivity Φ0.5mm equivalent flat hole).
Laser caliper: Outer diameter closed loop control (accuracy ±0.01mm).
3. Post-processing technology
Heat treatment: bright annealing (hydrogen nitrogen protection atmosphere) to eliminate stress, hardness fluctuation ≤3HRC.
Straightening: multi-roll precision straightening, straightness ≤0.5mm/m.
Surface treatment:
Electrolytic polishing (EP) : For medical/food grade stainless steel tubes, Ra up to 0.2μm.
Coating: hot dip galvanizing (zinc layer ≥80μm) or electroless nickel plating (uniform thickness ±2μm).
4. Typical application areas
Automobile manufacturing: fuel injection pipe (tolerance ±0.03mm), hydraulic pipe.
Semiconductor equipment: Ultra-high clean gas delivery pipe (inner wall EP treatment, particle ≤Class 5).
Medical instruments: endoscopic catheter (Φ1~5mm, wall thickness 0.1mm).
Energy industry: Instrument tubes for nuclear power plants (SA213-TP347H material, intergranular corrosion test passed).
5. Quality control standards
International standard:
ASTM A269 (Universal Seamless and Welded Austenitic Stainless Steel Pipe)
EN 10305-4 (Precision welded pipes for hydraulic systems)
Industry certification: ISO 9001, PED 2014/68/EU (Pressure Equipment Directive).
6. Technological trends
Intelligent production: AI algorithm optimizes welding parameters, and the yield is increased to more than 99.5%.
Composite process: laser + arc composite welding, both efficiency and quality (speed increased by 30%).
Green manufacturing: low energy high frequency power supply (efficiency ≥90%), waste acid recovery ≥95%.
Through the above process optimization and strict quality control, the high-precision steel pipe produced by the pipe welding machine can meet the demanding requirements of size, performance and reliability in high-end industrial fields. In actual production, the process route needs to be customized according to the material characteristics and uses, for example, medical tubes need to undergo additional passivation treatment and biocompatibility testing.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill

Time of issue : 2025-02-08
1.The role of pipe welding machine in the manufacture of automobile frame
Pipe production: The welding pipe machine is used to manufacture high-precision welded steel pipes, which constitute the longitudinal beams, beams, anti-collision beams and other key components of the automobile frame. High frequency welding (HFW) or laser welding technology can produce steel pipes with uniform wall thickness and strength of more than 800MPa to meet the needs of lightweight.
Customized processing: Through flexible forming technology, the welding machine can produce special-shaped cross section pipes (such as rectangular, trapezoidal), adapt to the topology optimization design of different models of frames, improve space utilization and impact energy absorption efficiency.
2.The core requirements of the welding pipe process for automobile frames
Material properties: DP600/DP800 duplex steel or 22MnB5 thermoforming steel should be used, and online heat treatment (such as induction annealing) should be carried out after welding to ensure the microstructure consistency between the weld zone and the base material and avoid HAZ (heat affected zone) softening.
Dimensional accuracy: Diameter tolerance should be controlled within ±0.2mm, ellipticity ≤0.5%, to ensure the matching accuracy of the assembly and stamping parts (clearance <0.5mm).
3.Key technology breakthrough point
Laser-MAG composite welding: the penetration depth can reach 8mm, the welding speed is increased to 6m/min, the heat input is reduced by 30%, and the welding deformation of the frame is significantly reduced (≤1.5mm/m).
Online quality monitoring: high-speed CCD vision system (sampling rate 2000fps) with eddy current detection, to achieve real-time detection of weld defects, miss rate <0.01%.
4.Cost-performance balance
Compared with the stamping and welding structure, the welded pipe frame can reduce the weight by 15-20%, the material utilization rate is increased to 95%, and the manufacturing cost of the bicycle is reduced by about 1200 yuan. However, it is necessary to increase the investment in roller forming molds (about 2 million yuan/set).
5.Industry Application Cases
- An independent brand pure level station adopts 3D variable cross-section welded pipe subframe, with torsional rigidity increased to 27000Nm/°, 40% higher than the traditional structure, and the battery pack space utilization increased by 12%.
Conclusion
The penetration rate of welded pipe technology in the field of automotive frames is growing at a rate of 8% per year, and future development directions include:
Intelligent welded pipe system (digital twin model real-time control molding parameters)
Magnesium alloy /CFRP composite pipe welding process
Topological optimization driven continuous forming technology for variable thickness pipes
It is recommended to pay attention to the update of the ISO 15614 standard and the latest certification requirements for automotive welded pipe processes in ASME BPVC Section IX to ensure technical compliance.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill
1.The role of pipe welding machine in the manufacture of automobile frame
Pipe production: The welding pipe machine is used to manufacture high-precision welded steel pipes, which constitute the longitudinal beams, beams, anti-collision beams and other key components of the automobile frame. High frequency welding (HFW) or laser welding technology can produce steel pipes with uniform wall thickness and strength of more than 800MPa to meet the needs of lightweight.
Customized processing: Through flexible forming technology, the welding machine can produce special-shaped cross section pipes (such as rectangular, trapezoidal), adapt to the topology optimization design of different models of frames, improve space utilization and impact energy absorption efficiency.
2.The core requirements of the welding pipe process for automobile frames
Material properties: DP600/DP800 duplex steel or 22MnB5 thermoforming steel should be used, and online heat treatment (such as induction annealing) should be carried out after welding to ensure the microstructure consistency between the weld zone and the base material and avoid HAZ (heat affected zone) softening.
Dimensional accuracy: Diameter tolerance should be controlled within ±0.2mm, ellipticity ≤0.5%, to ensure the matching accuracy of the assembly and stamping parts (clearance <0.5mm).
3.Key technology breakthrough point
Laser-MAG composite welding: the penetration depth can reach 8mm, the welding speed is increased to 6m/min, the heat input is reduced by 30%, and the welding deformation of the frame is significantly reduced (≤1.5mm/m).
Online quality monitoring: high-speed CCD vision system (sampling rate 2000fps) with eddy current detection, to achieve real-time detection of weld defects, miss rate <0.01%.
4.Cost-performance balance
Compared with the stamping and welding structure, the welded pipe frame can reduce the weight by 15-20%, the material utilization rate is increased to 95%, and the manufacturing cost of the bicycle is reduced by about 1200 yuan. However, it is necessary to increase the investment in roller forming molds (about 2 million yuan/set).
5.Industry Application Cases
- An independent brand pure level station adopts 3D variable cross-section welded pipe subframe, with torsional rigidity increased to 27000Nm/°, 40% higher than the traditional structure, and the battery pack space utilization increased by 12%.
Conclusion
The penetration rate of welded pipe technology in the field of automotive frames is growing at a rate of 8% per year, and future development directions include:
Intelligent welded pipe system (digital twin model real-time control molding parameters)
Magnesium alloy /CFRP composite pipe welding process
Topological optimization driven continuous forming technology for variable thickness pipes
It is recommended to pay attention to the update of the ISO 15614 standard and the latest certification requirements for automotive welded pipe processes in ASME BPVC Section IX to ensure technical compliance.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill

Time of issue : 2025-02-07
89 The working principle of the pipe welding machine 89 The pipe welding machine uncoils the steel strip, feeds and welds it into a round steel pipe, and then cools, straightens and cuts the steel pipe to the required length. The main steps include:
1. Uncoiling: Unroll the steel strip from the drum and level it through the straightener.
2. Forming: The steel strip is rolled into a tube shape through a series of roller wheels.
3. Welding: high frequency current is used to heat the joint of the steel strip, so as to weld the steel pipe.
4. Cooling: The welded steel pipe is cooled by cooling equipment.
5. Straightening and cutting: Finally, straighten and cut the steel pipe to the required length.
The main steel pipe used in the highway fence needs to have a certain strength and impact resistance, but also corrosion resistance. Specific features include:
1. High strength: the steel pipe must be able to withstand the impact to ensure the safety of the highway.
2. Corrosion resistance: steel pipes are usually galvanized to enhance their corrosion resistance and adapt to harsh outdoor environments.
3. Standard size: The steel pipe produced generally has strict size requirements to ensure the stability of the fixed connection of each fence.
The steel pipe produced by the 89 pipe welding machine plays a skeleton role in the highway fence, and its application is reflected in:
1. Guardrail: installed on both sides of the highway or in the middle, to prevent the vehicle from losing control of the road, to protect the safety of the driver.
2. Isolation belt: Set isolation belts between lanes in different directions to prevent vehicles from crossing lanes and reduce the incidence of accidents.
3. Sound barrier: The use of steel pipe frame to support the sound barrier plate to reduce the impact of road noise on the surrounding environment.
In short, the 89 pipe welding machine plays a key role in the production of steel pipes for highway fences, ensuring the stability, durability and safety of the fences, thus providing a reliable guarantee for the safe operation of the highways.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill
89 The working principle of the pipe welding machine 89 The pipe welding machine uncoils the steel strip, feeds and welds it into a round steel pipe, and then cools, straightens and cuts the steel pipe to the required length. The main steps include:
1. Uncoiling: Unroll the steel strip from the drum and level it through the straightener.
2. Forming: The steel strip is rolled into a tube shape through a series of roller wheels.
3. Welding: high frequency current is used to heat the joint of the steel strip, so as to weld the steel pipe.
4. Cooling: The welded steel pipe is cooled by cooling equipment.
5. Straightening and cutting: Finally, straighten and cut the steel pipe to the required length.
The main steel pipe used in the highway fence needs to have a certain strength and impact resistance, but also corrosion resistance. Specific features include:
1. High strength: the steel pipe must be able to withstand the impact to ensure the safety of the highway.
2. Corrosion resistance: steel pipes are usually galvanized to enhance their corrosion resistance and adapt to harsh outdoor environments.
3. Standard size: The steel pipe produced generally has strict size requirements to ensure the stability of the fixed connection of each fence.
The steel pipe produced by the 89 pipe welding machine plays a skeleton role in the highway fence, and its application is reflected in:
1. Guardrail: installed on both sides of the highway or in the middle, to prevent the vehicle from losing control of the road, to protect the safety of the driver.
2. Isolation belt: Set isolation belts between lanes in different directions to prevent vehicles from crossing lanes and reduce the incidence of accidents.
3. Sound barrier: The use of steel pipe frame to support the sound barrier plate to reduce the impact of road noise on the surrounding environment.
In short, the 89 pipe welding machine plays a key role in the production of steel pipes for highway fences, ensuring the stability, durability and safety of the fences, thus providing a reliable guarantee for the safe operation of the highways.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill

Time of issue : 2025-01-23
1.Supply channels:
Online marketplaces: For example, Taobao, Alibaba, Jingdong and other platforms can search and find used equipment.
Professional used equipment market: Some areas have a special used equipment market, you can view the equipment situation on the spot.
Industry exhibitions: Participate in machinery, manufacturing related exhibitions, sometimes you can find suppliers to provide second-hand equipment opportunities.
Peers and recommendations: Ask peers and friends in the industry to obtain reliable equipment and supplier information.
2.Selection criteria:
Equipment condition: Carefully check the service life, maintenance records and running status of the equipment to ensure that the function is intact.
Brand and model: Choose well-known brands and reliable models, usually the quality is guaranteed, and the after-sales service is relatively perfect.
Price comparison: multiple inquiries to ensure reasonable prices to avoid buying inferior equipment at low prices.
Service and Accessories: Find out if the supplier provides after-sales service and accessories to ensure convenient maintenance in subsequent use.
3.Site inspection:
Equipment operation demonstration: The seller is required to perform equipment operation demonstration to observe the actual operation.
Technical Support: Evaluate the seller's technical support capabilities, including whether to provide installation and commissioning services.
Contract protection: Sign a detailed procurement contract to clarify the responsibilities of both parties, equipment specifications, payment methods, after-sales service and other content.
4.Trial Period:
Trial commitment: Try to strive for a certain trial period in order to find potential problems with the equipment during use.
Troubleshooting: During the trial period, pay close attention to the operation of the equipment, if there is a failure, contact the seller as soon as possible.
Through the above methods, you can better purchase a satisfactory second-hand pipe making machine.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill
1.Supply channels:
Online marketplaces: For example, Taobao, Alibaba, Jingdong and other platforms can search and find used equipment.
Professional used equipment market: Some areas have a special used equipment market, you can view the equipment situation on the spot.
Industry exhibitions: Participate in machinery, manufacturing related exhibitions, sometimes you can find suppliers to provide second-hand equipment opportunities.
Peers and recommendations: Ask peers and friends in the industry to obtain reliable equipment and supplier information.
2.Selection criteria:
Equipment condition: Carefully check the service life, maintenance records and running status of the equipment to ensure that the function is intact.
Brand and model: Choose well-known brands and reliable models, usually the quality is guaranteed, and the after-sales service is relatively perfect.
Price comparison: multiple inquiries to ensure reasonable prices to avoid buying inferior equipment at low prices.
Service and Accessories: Find out if the supplier provides after-sales service and accessories to ensure convenient maintenance in subsequent use.
3.Site inspection:
Equipment operation demonstration: The seller is required to perform equipment operation demonstration to observe the actual operation.
Technical Support: Evaluate the seller's technical support capabilities, including whether to provide installation and commissioning services.
Contract protection: Sign a detailed procurement contract to clarify the responsibilities of both parties, equipment specifications, payment methods, after-sales service and other content.
4.Trial Period:
Trial commitment: Try to strive for a certain trial period in order to find potential problems with the equipment during use.
Troubleshooting: During the trial period, pay close attention to the operation of the equipment, if there is a failure, contact the seller as soon as possible.
Through the above methods, you can better purchase a satisfactory second-hand pipe making machine.
For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier:www.usedpipemill.com
JinYuJie-Used Pipe Mills Supplier(Please click the link→) :second-hand pipe mill
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Email: zty@usedpipemill.com
Company address:No. A99, East Lecong Avenue, Lecong Town, Foshan City, Guangdong Province
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