Introduction

High-frequency pipe welding machine is one of the commonly used equipment in modern industrial production. It is widely used in many fields such as petroleum, chemical, construction, automobile, electric power and so on. High-frequency welded pipe has gradually become the mainstream of the market with its advantages of high production efficiency, low cost and stable quality. In this paper, the production process of high-frequency welded pipe machine will be elaborated in detail, in order to provide reference for relevant practitioners.

 High-frequency pipe welding machine production process

High-frequency pipe welding machine production process mainly includes the following steps:

1.1 Raw material preparation: Choose qualified steel strip as raw materials to ensure that its mechanical properties, surface quality and geometric dimensions to meet the production requirements. The steel strip usually needs to be pre-treatment such as straightening and shearing.

1.2 Unwinding and leveling: The steel strip is unwound and leveled by the leveling machine to eliminate the bending and wavy shape of the steel strip during transportation and storage to ensure the accuracy of subsequent forming.

1.3 Butt-welding of steel strip: If the length of steel strip is not enough, butt-welding operation is needed to weld two sections of steel strip into one long strip. Butt welding needs to strictly control the welding quality and joint position to avoid affecting the subsequent forming and welding.

1.4 Forming: The leveled steel strip is fed into the forming machine, and the strip is gradually pressed into a pipe billet with round cross-section through multiple roll presses. In this process, the roller pressure and speed should be controlled to ensure the geometric size and shape accuracy of the billet.

1.5 High-frequency welding: High-frequency welding is the core process of high-frequency welded pipe production. Through the principle of electromagnetic induction, the steel at the edge of the weld is locally heated to a molten state, and the butt weld is crystallized by roller pressure to form a solid weld. High-frequency welding includes contact welding and induction welding in two ways, the specific choice depends on the production requirements and equipment configuration.

1.6 Burr removal: After welding is completed, burrs will be produced at the weld seam, which need to be removed by the removal equipment to ensure the surface quality of the steel pipe.

1.7  Sizing and cutting:  Put the welded and deburred steel pipe into sizing machine, by adjusting the angle and stroke of sizing rollers to achieve the required outer diameter and thickness.  Then, the flying saw will cut the pipe to required length.

1.8  Defect detection and testing: Perform flaw detection test on the cut steel pipe, including hydraulic test, flattening test, impact test, etc., to ensure that the quality and performance of the steel pipe meet the standard.

1.9 Printing and coating: Print information on the surface of the steel pipe, such as specification, production batch, etc., and coating treatment to improve the corrosion resistance and aesthetics of the steel pipe.

1.10 Finished product storage: After a series of testing and processing, qualified steel pipes are sent to the finished product storage, waiting to be released for sale or further processing.

2. High-frequency welding process parameters

High-frequency welding process, the control of process parameters on the welding quality is critical. The main process parameters include:

2.1 Welding heat input: determined by the welding power and welding time, directly affecting the welding temperature. Insufficient heat input will lead to unfused or cold welding, and excessive heat input will produce overheating, overburning or even weld breakdown.

2.2 Welding pressure: In the welding process, the pressure exerted by the extrusion roller. Welding pressure is too small will lead to a reduction in the strength of the weld, easy to produce cracks and inclusions. If the welding pressure is too high, it will produce defects such as excessive internal and external burrs or lap welding.

2.3 Welding speed: welding speed affects the heating time and weld quality. Welding speed can improve productivity, but too fast welding speed may lead to insufficient heating of the weld, affecting the weld quality.

2.4 Opening angle (V angle): refers to the angle of the strip edge before the extrusion roller. The size of the opening angle affects the neighboring effect and heating effect of the high-frequency current, thus affecting the quality of the weld.

2.5  Induction ring and impedance position: induction ring and impedance position directly affects the welding efficiency and weld quality. Reasonable position arrangement can improve the heating efficiency, reduce heat loss and improve the quality of the weld.

3、Reasons of high-frequency welding pipe quality

In the welding pipe production procedures, the main reasons of affecting product quality has following aspects:

3.1 Raw material quality: Including the mechanical properties, surface quality and geometry of the steel strip. Unstable raw material quality will directly affect the forming and welding quality of steel pipe.

3.2 Welding technology: including the control of welding process parameters, commissioning and maintenance of welding equipment. Welding technology directly determines the quality of the weld and the mechanical properties of steel pipe.

3.3 Roll adjustment: the adjustment of the roll has a great influence on the forming accuracy and surface quality of the steel pipe. Improper adjustment will lead to the surface of the steel pipe distortion, lap, edge wave and other defects.

3.4 Equipment failure: equipment failure in the production process will lead to production interruption or product quality decline. Therefore, the equipment should be regularly checked and maintained to ensure the stability and reliability of the equipment.

3.5 Production environment: the temperature, humidity and cleanliness of the production environment will also affect the production quality and production efficiency of steel pipe. The production environment should be controlled within the appropriate range to ensure smooth production.

4. Conclusion

High-frequency pipe welding process is a flexible and precise procedures, it involves the control of many steps and parameters.  Through reasonable process design and strict process parameters, it produces high quality and high efficiency pipe. To enhance the level of high- frequency welding pipe process technology, the suggestions are following:

5.Optimization measure and technology renovation

5.1 Automatic control: Introduction intelligent control system, using sensor, PLC (Programmable Logic Controller) and intelligent algorithms, real-time monitoring and adjustment of various parameters in the production process, such as welding power, welding speed, pressure, etc., to achieve precise control and improve production efficiency and product quality.

5.2 Automation equipment upgrading: automation upgrading of existing equipment, such as the use of automatic feeding, automatic leveling, automatic inspection and other systems to reduce manual intervention, reduce labor intensity, improve production stability and safety.

5.3 Environmental protection and energy saving: Development and application of more environmentally friendly, energy-saving welding technology and equipment, such as the use of energy-efficient high-frequency power supply, optimize the cooling system, reduce emissions and wastewater emissions, reduce energy consumption and environmental pollution.

5.4 Process research and improvement: strengthen the research of high-frequency welding process, explore the application of new materials, new technologies, such as the development of high-strength, corrosion-resistant special welding consumables, improve the structure of welded joints, improve the mechanical properties of welds and corrosion resistance.

5.5 Quality control system: establish a perfect quality control system, from raw materials into the factory to the finished product factory, the whole process of quality control and testing to ensure that each process meets the standard requirements to improve the overall product quality.

5.6 Personnel training and skills upgrading: Strengthen the training and skills upgrading of operators, improve their understanding and mastery of the high-frequency pipe welding machine production process, enhance their ability to solve practical production problems, and provide strong support for the optimization and improvement of the production process.

6. The future development trend

With the progress of science and technology and industrial development, high-frequency pipe welding machine production process will show the following development trend:

6.1 High degree of automation and intelligence: the future of high-frequency welded pipe machine will rely more on automation and intelligent technology to achieve comprehensive automation and intelligent control of the production process, improve production efficiency and product quality.

6.2 Green and energy saving: environmental protection and energy saving will become an important direction of development of high-frequency pipe welding machine production process, promoting welding technology and equipment green, energy-saving transformation.

6.3 personalized and customized production: with the diversification of market demand, high-frequency pipe welding machine production process will pay more attention to personalized and customized production to meet the special needs of different customers.

6.4. Digitalization and networking: digitalization and networking technology will be deeply integrated into the high-frequency welded pipe machine production process to achieve real-time collection, analysis and sharing of production data to enhance the level of refinement of production management.

6.5. Application of new materials and new technologies: with the continuous development of new materials and new technologies, high-frequency welded pipe machine production process will continue to expand the application areas, improve the added value of products and market competitiveness.

In short, high-frequency welded pipe machine production process is a continuous development and improvement process. Through continuous technological innovation, process optimization and quality control system construction, we can promote the continuous development and progress of high frequency welded pipe machine production process, and provide more high-quality, efficient and environmentally friendly products and services for related industries.