Analysis of quality defects in welding section of pipe welder machine
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【概要描述】The weld seam is the most important sign of the quality of the welded pipe and the life of the welded pipe. Therefore, the analysis and treatment of quality defects in the welding section of the pipe welder machine should be carried out around the weld. The main defects of the weld include cracks, cracks, incomplete penetration, over-burning and perforation, and dislocation of the weld.
Analysis of quality defects in welding section of pipe welder machine
【概要描述】The weld seam is the most important sign of the quality of the welded pipe and the life of the welded pipe. Therefore, the analysis and treatment of quality defects in the welding section of the pipe welder machine should be carried out around the weld. The main defects of the weld include cracks, cracks, incomplete penetration, over-burning and perforation, and dislocation of the weld.
- Sort:Information
- Auth:
- Source:
- Release time:2022-04-29 11:30
- Pvs:
The weld seam is the most important sign of the quality of the welded pipe and the life of the welded pipe. Therefore, the analysis and treatment of quality defects in the welding section of the pipe welder machine should be carried out around the weld. The main defects of the weld include cracks, cracks, incomplete penetration, over-burning and perforation, and dislocation of the weld.
①Weld cracking:
Weld cracking includes natural cracking (including stress corrosion) and stress (additional external force) cracking.
1.Natural cracking of welds
Features: Natural cracking of the weld refers to the cracking of the weld without any additional external force at the cooling water tank, sizing machine, warehouse, etc. after the welded pipe leaves the constraint of the squeeze roller.
This kind of crack is like a zigzag, showing a grayish metallic luster. The most notable feature is that there is no external force, and there is no reason for cracking.
Causes: There are many reasons for the natural cracking of the weld, the main reasons are insufficient extrusion force, low or high welding temperature, narrow and thin tube blank, deep burr removal, butt welding surface ︿ shape Or reverse ﹀-shaped butt and high-strength tube ring caused by excessive residual tensile stress in transverse forming, etc.
Measures to prevent natural cracking of welds include:
1) Strictly inspect the raw materials and remove the hard tube blanks;
2) For different tube blanks, select a positive and stable welding process to avoid cold welding and overburning;
3) Strengthen the forming adjustment, reduce the residual stress of the forming, and realize the parallel butt joint of the welding seam.
2.Weld stress cracking
Cracked flattened welds. Including positive squashing and side squashing and cracking.
Flattening can be divided into D/3 flattening and full flattening; according to the relevant standards in my country, the weld is qualified without cracking after D/3 under positive pressure; however, from the actual use of welded pipes, most of them require full flattening without cracking. cracked. The so-called full flattening means 100% reduction to the inner wall of the tube with a clearance of 0. Full flattening can not only check the welding quality, but also check the plastic state of the tube blank.
Positive pressure weld cracking: refers to the flattening and cracking of the weld position and the force application direction on the same line. The mechanism of positive pressure internal cracking of thick-walled pipes is that the outer circular weld of the welded pipe is compressed during positive pressure, the inner circular weld is stretched, and the inner side of the weld is easily cracked.
The main reasons are: excessive deformation of the edge of the tube blank, and the welding seam is in a "︿" shape butt; the extrusion force is too small; the welding heat is insufficient; the tube blank is hard, and the weld seam is easy to crack after being stressed.
The main measures to eliminate the internal cracking of the positive pressure weld of the thick-walled pipe are: appropriately relax the first forming flat roll (referring to the W pass, edge deformation pass and comprehensive deformation pass) and closed hole roll, and at the same time increase the extrusion force, increase welding heat, and reject tube blanks that are too hard.
3.Lateral pressure weld cracking: refers to the complete cracking, partial cracking or cracking of the welding seam when the direction of the flattening force is 90° to the welding seam. The cracking mechanism of the lateral pressure weld is just the opposite of that of the positive pressure. When the lateral pressure is applied, the outer layer of the weld is in a stretched state, and the more the pressure is pressed, the smaller the curvature radius of the weld position, and the greater the tensile stress of the outer layer of the weld, the more It is easy to tear the weld and cause lateral pressure cracking.
The main adjustment measures are: increase the extrusion force and increase the welding heat; improve the forming quality, and strive to realize the parallel butt joint of the welding seam.
The elbow weld is cracked. There are two types of cracks in elbow welds: process-type cracking and strength-type cracking.
4.Process type elbow weld cracking: refers to the unequal extension or compression of the longitudinal fibers of the welded pipe due to the pipe bending process when the pipe welder machine. Causes longitudinal fibers to dislocate each other and to stagger and crack at the weakest weld. If the weld is placed on the outside of the bending arc, the tensile stress on the outside of the weld is the largest. The weld and nearby longitudinal fibers with different elongations will cause dislocation of the lattice between the structures. However, the tensile strength of the weld structure is generally lower than that of the base metal, so the longitudinal direction is prone to occur at the weakest weld. Staggered cracking and lateral fracture.
In the same way, when the weld is on the inside of the bending arc, the weld structure and its nearby metal structures will undergo longitudinal plastic compression deformation. Because of their different compressive plastic deformation capabilities, the weld is the weakest part, so the longitudinal fibers are not equal. Extrusion and flow can easily cause dislocation cracking of welds with low strength.
Therefore, in order to prevent process-type cracking of welds, in addition to optimizing the performance of the welds, on the other hand, it is recommended that the user place the welds on the bending neutral layer as much as possible, so that the welds are only subjected to a small amount of stretching during the bending process of the welded pipe. Along with the compression, the tension and compression of the fibers around the weld is also limited. Of course, if the weld is strong, performant, and soft, then no matter where the weld is placed to bend, cracking of the weld will not occur.
5.Strength type elbow weld cracking: refers to the elbow weld cracking that occurs on the premise that the chemical composition of the tube blank, the mechanical properties are good, and the weld is in the area near the neutral layer. The cause of low weld strength should be looked for. Improve weld strength.
Weld cracking caused by tube opening, flanging, taper tube, flaring, etc. To analyze the specific situation, on the premise of not exceeding the transverse elongation of the pipe, we should find out the reasons from the factors affecting the strength of the weld, and take measures to enhance the strength of the weld.
②Weld cracks
Weld cracks refer to the existence of small hair-like cracks in the weld. Most of these cracks occur on the superficial part of the weld; some can be seen at a glance, while others need to be carefully identified or even magnified to be discovered.
The reasons for the cracks are nothing more than the following:
(1) Reflow slag inclusion caused by high welding temperature.
(2) The tube blank is thin and narrow and the extrusion force is low, and some oxides are not extruded from the weld, and non-metallic inclusions are formed after cooling.
(3) There are non-penetrating lack of meat and micro-cracks on the edge of the formed tube blank.
(4) The welding seam is V-shaped butt, the superficial layer fusion tissue is loose, and the cold shrinkage stress will tear the loose tissue.
(5) The chemical composition of the edge of the tube blank is segregated and the oxide layer is thick, resulting in non-metallic inclusions with high melting point.
Most of the welded pipes with cracks can pass the hydrostatic test, but it is difficult to pass the non-destructive testing and side flattening test. Usually, the opening angle can be appropriately increased. Increase the squeezing force. Increase the soldering temperature. Measures such as improving the edge docking state are eliminated.
③ Welding seam dislocation
Weld dislocation refers to the weld formed by welding two pairs of welding surfaces not on the same plane. Weld dislocation is divided into three types: tendency weld dislocation, occasional weld dislocation and periodic weld dislocation; however, they have a common defect feature, that is, after the normal removal of external burrs, one side of the weld still remains Outer burrs. Dislocation of the weld seam will not only cause the surface of the weld seam to be unsmooth and affect the surface quality, but also reduce the welding area and reduce the strength of the weld seam.
There are many causes of weld dislocation, which are roughly as follows:
(1) The two sides of the first and second flat rollers are pressed asymmetrically;
(2) There is asymmetry, beating, non-concentricity, etc. in the extrusion roller, closed-hole roller or guide roller;
(3) The forming flat roller bearing, vertical roller bearing, guide roller bearing, squeeze roller bearing, etc. are damaged but have not been found;
(4) The thickness of the tube blank, the width and the narrow tolerance are large, S bend, sickle bend and other;
(5) The operation of the tube blank is unstable, and the left and right swing is large;
(6) There is an invisible bulge in the formed tube blank;
(7) The squeeze roll and guide roll deviate from the rolling center line seriously.
The causes of weld misalignment are complex and may be caused by a single cause, or it may be the result of a combination of several causes. The specific search should be based on the principle of first easy and then difficult, starting from the reasons that are visible and tangible, and eliminate them one by one and take corresponding measures.
④Incomplete penetration
The notable feature of incomplete weld penetration (also known as cold welding) is that the weld has an obvious (under-penetration) or inconspicuous (slight under-penetration) groove or dark line, which mostly exists in thick-walled pipes. On the outer wall, and sometimes also on the inner wall.
The essence of incomplete penetration is that the crystallization behavior of the weld is only completed in part of the thickness direction of the tube blank, and the other parts are also heated, but the conditions for metal crystallization are not reached.
Incomplete penetration is a serious quality defect, and the reasons for incomplete penetration of the outer wall are roughly as follows:
(1) low temperature welding;
(2) Insufficient extrusion force;
(3) The welding speed is too fast;
(4) The magnet bar is demagnetized, the welding temperature is slowly lowered, and the operator is not aware of it in time;
(5) The edge of the formed tube blank is deformed and the upper edge of the extrusion roller hole is severely worn, resulting in a sharp V-shaped butt joint on the edge of the tube ring;
(6) Improper application of coolant, pour directly onto the V-shaped loop at the edge of the heating tube blank.
It should be pointed out that the dark line at the weld position is often misjudged as the scratch mark left by the removal of the outer burr.
The identification method is to wipe with sandpaper. After wiping off the surface layer, if the black line is still seen, it means that the welding is not penetrated; the second is to do the side flattening test.
The measures to exclude incomplete penetration of the outer wall are:
(1) Reduce the welding speed, increase the welding heat, and increase the extrusion force, which can be implemented individually or simultaneously;
(2) Strengthen the edge forming of the tube blank, and strive to realize the parallel butt joint of the welding edge;
(3) Replace the severely worn guide rollers and squeeze rollers in time;
(4) Check the magnet bar to ensure that it is not demagnetized;
(5) Avoid pouring the coolant directly onto the edge of the heating tube blank.
⑤ Over-burning and perforation
Overburning is a prelude to perforation, and perforation is the product of severe overburning.
Main causes of overburning and perforation:
(1)The opening angle is too small, which leads to the long liquid lintel and unstable burning;
(2)The welding speed is slow and the welding heat is too high;
(3) That the welding speed is unstable, the tube blank runs slippery, and it is prone to overburning at the moment of slippage;
(4) the welding temperature of the thin-walled tube is too high, and the opening angle is too small.
Measures to prevent burns and perforations are:
(1) Appropriately increase the opening angle to reduce welding heat input;
(2) Increase the rolling force of the flat roll and reduce the deformation force of the vertical roll to eliminate the slip of the unit;
(3) The welding process of high speed, low heat and low extrusion force should be selected for thin-walled tubes.
The above are the 5 reasons for the quality defects of the welding section of the pipe welder machine. Hope to be of some help to you. Our company has many brands and wide resources, there is always one suitable for you. You only need to inform us of your pipe manufacturing needs, and our company will provide you with used welded pipe equipment that really suits your needs.
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Time of issue : 2025-02-13
1.Equipment condition check
Appearance inspection: Check whether the equipment has obvious damage, rust or deformation.
Core component inspection: Focus on inspecting key components such as welding joints, transmission systems, and electrical systems to ensure that there is no serious wear or failure.
Operation test: Conduct trial operation to observe whether the equipment runs smoothly and whether the welding quality meets the requirements.
2.Equipment history
Service life: Understand the use time of the equipment, usually the longer the service life, the higher the risk of failure.
Maintenance records: Check the maintenance and repair records of the equipment to determine whether it is well maintained.
Working environment: Understand the working environment before the equipment, harsh environment may lead to increased equipment wear.
3.Technical parameters
Production capacity: Confirm whether the production capacity of the equipment meets the demand, including welding speed, pipe diameter range, etc.
Accuracy requirements: Check the welding accuracy of the equipment to ensure that it meets the production standard.
Compatibility: Confirm whether the equipment can be adapted to existing production lines or raw materials.
4.Brand and model
Brand reputation: Choose a well-known brand, usually the quality and after-sales service is more guaranteed.
Model suitability: Ensure that the model is suitable for current production needs and avoid insufficient or excessive functions.
5.Price evaluation
Market conditions: Understand the market price of the same type of equipment, to avoid too high or too low prices.
Cost performance: Considering the equipment condition, performance and price, choose cost-effective equipment.
6.After-sales service
Warranty Period: Confirm whether the equipment is under warranty, or whether the warranty can be extended.
Technical Support: Find out if the supplier provides technical support or repair services.
Accessories supply: Confirm that equipment accessories are easy to obtain to avoid the risk of stopping production.
7.Legal and Compliance
Equipment legitimacy: Ensure that the source of equipment is legitimate, avoid buying stolen goods or illegal equipment.
Compliance: Verify that the equipment meets local safety standards and environmental requirements.
8.Supplier reputation
Supplier background: Choose suppliers with good reputation to reduce the risk of purchase.
User Reviews: View other users' reviews of suppliers to understand their service quality and equipment condition.
9.Transportation and installation
Transportation costs: Consider the transportation costs of equipment, especially large equipment.
Installation and commissioning: Confirm whether the supplier provides installation and commissioning services to ensure the normal use of the equipment.
10.Contract Terms
Clear terms: Ensure that key information such as equipment condition, price, warranty period, etc. is clear in the contract.
Return Policy: Understand the return policy to avoid the inability to return if the equipment does not meet the requirements.
Summary
The purchase of second-hand pipe welding machine needs to consider the equipment status, history, technical parameters, price, after-sales service and other factors to ensure that the equipment meets the production demand and is cost-effective.
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.Equipment condition check
Appearance inspection: Check whether the equipment has obvious damage, rust or deformation.
Core component inspection: Focus on inspecting key components such as welding joints, transmission systems, and electrical systems to ensure that there is no serious wear or failure.
Operation test: Conduct trial operation to observe whether the equipment runs smoothly and whether the welding quality meets the requirements.
2.Equipment history
Service life: Understand the use time of the equipment, usually the longer the service life, the higher the risk of failure.
Maintenance records: Check the maintenance and repair records of the equipment to determine whether it is well maintained.
Working environment: Understand the working environment before the equipment, harsh environment may lead to increased equipment wear.
3.Technical parameters
Production capacity: Confirm whether the production capacity of the equipment meets the demand, including welding speed, pipe diameter range, etc.
Accuracy requirements: Check the welding accuracy of the equipment to ensure that it meets the production standard.
Compatibility: Confirm whether the equipment can be adapted to existing production lines or raw materials.
4.Brand and model
Brand reputation: Choose a well-known brand, usually the quality and after-sales service is more guaranteed.
Model suitability: Ensure that the model is suitable for current production needs and avoid insufficient or excessive functions.
5.Price evaluation
Market conditions: Understand the market price of the same type of equipment, to avoid too high or too low prices.
Cost performance: Considering the equipment condition, performance and price, choose cost-effective equipment.
6.After-sales service
Warranty Period: Confirm whether the equipment is under warranty, or whether the warranty can be extended.
Technical Support: Find out if the supplier provides technical support or repair services.
Accessories supply: Confirm that equipment accessories are easy to obtain to avoid the risk of stopping production.
7.Legal and Compliance
Equipment legitimacy: Ensure that the source of equipment is legitimate, avoid buying stolen goods or illegal equipment.
Compliance: Verify that the equipment meets local safety standards and environmental requirements.
8.Supplier reputation
Supplier background: Choose suppliers with good reputation to reduce the risk of purchase.
User Reviews: View other users' reviews of suppliers to understand their service quality and equipment condition.
9.Transportation and installation
Transportation costs: Consider the transportation costs of equipment, especially large equipment.
Installation and commissioning: Confirm whether the supplier provides installation and commissioning services to ensure the normal use of the equipment.
10.Contract Terms
Clear terms: Ensure that key information such as equipment condition, price, warranty period, etc. is clear in the contract.
Return Policy: Understand the return policy to avoid the inability to return if the equipment does not meet the requirements.
Summary
The purchase of second-hand pipe welding machine needs to consider the equipment status, history, technical parameters, price, after-sales service and other factors to ensure that the equipment meets the production demand and is cost-effective.
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 : 2025-02-12
1. Material basis: Welded pipe as the skeleton material of furniture
Structural support: Steel pipes made of welded pipes are often used in the frame structure of furniture, such as chair legs, table supports, bed frames, bookshelves, etc. Its high strength and stability can withstand large loads.
Lightweight design: Compared with solid steel, welded pipe is lightweight and low cost, suitable for furniture requiring portability or simple design (such as outdoor folding tables and chairs).
2. Design flexibility
Diversified modeling: Welded pipes can be processed into complex shapes through bending, cutting, welding and other processes to meet the curve or geometric design needs of modern furniture (such as streamlined bar chairs, creative shelves).
Industrial style: The exposed metal welded pipe structure is the iconic element of industrial furniture, often used in cafes, LOFT Spaces and other scenes.
3. Functionality and durability
Outdoor furniture: Galvanized welded pipes or steel pipes treated with anti-rust are often used in outdoor furniture (such as garden tables and chairs, balcony guardrail), with strong weather resistance.
Load-bearing requirements: The high strength characteristics of welded pipes are suitable for the production of storage shelves, shelves and other furniture requiring high load-bearing.
4. Production process coordination
Mass production: The efficient production mode of welded pipe mechanism is matched with the large-scale demand of furniture manufacturing, reducing raw material costs.
Customized processing: Furniture factories can customize welded pipes of different specifications (such as diameter and wall thickness) according to design requirements to improve product adaptability.
5. Environmental Protection and Sustainability
Material recycling: Steel can be recycled, in line with the design concept of environmentally friendly furniture.
Surface treatment: Spraying, painting and other processes can improve the beauty and durability of welded pipe furniture, while reducing the environmental burden.
6. Market trends
Modular furniture: The standardized interface of welded pipe structure is easy to assemble and disassemble, catering to the popular trend of modular furniture.
Cross-border combination: Welded pipes are often combined with wood, glass, plastic and other materials to create a mixed-match style (such as metal + wood dining tables).
Typical Application Case
Office furniture: Steel desk bracket, conference chair frame.
Home Decoration: Metal bookshelf, coat rack, lamp stand.
Public Facilities: Park benches, shopping mall display shelves.
Summary
The welded pipe mechanism provides the furniture industry with an economical, durable and flexible material solution that drives innovation in the function, aesthetics and sustainability of modern furniture. Its combination with furniture is not only an extension of industrial technology, but also an expansion of design language.
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. Material basis: Welded pipe as the skeleton material of furniture
Structural support: Steel pipes made of welded pipes are often used in the frame structure of furniture, such as chair legs, table supports, bed frames, bookshelves, etc. Its high strength and stability can withstand large loads.
Lightweight design: Compared with solid steel, welded pipe is lightweight and low cost, suitable for furniture requiring portability or simple design (such as outdoor folding tables and chairs).
2. Design flexibility
Diversified modeling: Welded pipes can be processed into complex shapes through bending, cutting, welding and other processes to meet the curve or geometric design needs of modern furniture (such as streamlined bar chairs, creative shelves).
Industrial style: The exposed metal welded pipe structure is the iconic element of industrial furniture, often used in cafes, LOFT Spaces and other scenes.
3. Functionality and durability
Outdoor furniture: Galvanized welded pipes or steel pipes treated with anti-rust are often used in outdoor furniture (such as garden tables and chairs, balcony guardrail), with strong weather resistance.
Load-bearing requirements: The high strength characteristics of welded pipes are suitable for the production of storage shelves, shelves and other furniture requiring high load-bearing.
4. Production process coordination
Mass production: The efficient production mode of welded pipe mechanism is matched with the large-scale demand of furniture manufacturing, reducing raw material costs.
Customized processing: Furniture factories can customize welded pipes of different specifications (such as diameter and wall thickness) according to design requirements to improve product adaptability.
5. Environmental Protection and Sustainability
Material recycling: Steel can be recycled, in line with the design concept of environmentally friendly furniture.
Surface treatment: Spraying, painting and other processes can improve the beauty and durability of welded pipe furniture, while reducing the environmental burden.
6. Market trends
Modular furniture: The standardized interface of welded pipe structure is easy to assemble and disassemble, catering to the popular trend of modular furniture.
Cross-border combination: Welded pipes are often combined with wood, glass, plastic and other materials to create a mixed-match style (such as metal + wood dining tables).
Typical Application Case
Office furniture: Steel desk bracket, conference chair frame.
Home Decoration: Metal bookshelf, coat rack, lamp stand.
Public Facilities: Park benches, shopping mall display shelves.
Summary
The welded pipe mechanism provides the furniture industry with an economical, durable and flexible material solution that drives innovation in the function, aesthetics and sustainability of modern furniture. Its combination with furniture is not only an extension of industrial technology, but also an expansion of design language.
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 : 2025-02-11
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
Wechat: 13392281699
Email: zty@usedpipemill.com
Company address:No. A99, East Lecong Avenue, Lecong Town, Foshan City, Guangdong Province
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Tel (wechat): 13336487288
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Email: zty@usedpipemill.com
Address: No. A99, Lecong Avenue East, Lecong Town, Foshan City, Guangdong Province
