UNS N08825 การวิจัยกระบวนการเชื่อมโลหะผสมนิกเกิลที่ใช้
Research on Welding Process of UNS N08825 Nickel-Based Alloy Pipelines
1. Introduction to UNS N08825 Nickel-Based Alloy
1.1 Chemical Composition and Material Properties
สหรัฐอเมริกา N08825 (ความไม่สงบ 825) เป็นโลหะผสมนิกเกิล-เหล็ก-โครเมียมที่มีการเติมโมลิบดีนัม, ทองแดง, และไทเทเนียม. Its chemical composition is meticulously designed to achieve exceptional corrosion resistance and mechanical stability in harsh environments (#user-content-ref-1)(#user-content-ref-3):
- นิกเกิล (38–46%): Enhances resistance to chloride-induced stress corrosion cracking and acidic media (เช่น, sulfuric and phosphoric acids).
- โครเมียม (19.5–23.5%): Forms a protective oxide layer against oxidation and pitting corrosion.
- โมลิบดีนัม (2.5–3.5%) and Copper (1.5–3%): Improve resistance to reducing acids, particularly sulfuric acid.
- ไทเทเนียม (0.6–1.2%): Stabilizes the alloy against intergranular corrosion during welding.
Mechanical properties under ASTM/ASME standards include:
- ความต้านทานแรงดึง: 550–585 MPa
- ความแข็งแรงของผลผลิต: 240–275 MPa
- การยืดตัว: ≥30% (#user-content-ref-2)(#user-content-ref-6).
1.2 Applications in Industrial Sectors
This alloy is widely used in:
- น้ำมัน & Gas: ท่อส่งใต้ทะเล, acid gas handling systems.
- การแปรรูปทางเคมี: เครื่องปฏิกรณ์, เครื่องแลกเปลี่ยนความร้อน.
- พลังงานนิวเคลียร์: Coolant systems, spent fuel storage (#user-content-ref-5)(#user-content-ref-46).
2. Welding Methods for UNS N08825 Pipelines
2.1 Common Welding Techniques
2.1.1 ทีไอจี (GTAW) การเชื่อม
- ข้อดี: Precise heat control, รอยเชื่อมคุณภาพสูง, minimal spatter.
- พารามิเตอร์:
- Current: 90–150 A (DCEN polarity).
- Voltage: 10–15 V.
- Shielding gas: Argon or Ar-He mixtures (flow rate: 10–15 L/min) (#user-content-ref-7)(#user-content-ref-22).
- การใช้งาน: Root passes in critical pipelines requiring defect-free joints.
2.1.2 ฉัน (การยิง) การเชื่อม
- ข้อดี: High deposition rates, suitable for thick-walled pipes.
- พารามิเตอร์:
- Current: 120–200 A.
- Wire feed speed: 4–8 m/min.
- Shielding gas: 98% Ar + 2% CO₂ (#user-content-ref-12)(#user-content-ref-24).
2.1.3 สมาว (การเชื่อมอาร์คโลหะป้องกัน)
- ข้อดี: Flexibility in field welding.
- Electrodes: AWS ENiCrMo-3 for matching corrosion resistance.
- ความท้าทาย: Requires skilled operators to manage slag inclusion risks (#user-content-ref-8)(#user-content-ref-11).
2.2 Welding Material Selection
- ฟิลเลอร์โลหะ: ernichrmo-3 (TIG/MIG) or ENiCrMo-3 (สมาว) to match base metal composition.
- การทำความสะอาดก่อนการเชื่อม: Acetone or alcohol degreasing to remove sulfur, zinc, และสารปนเปื้อนอื่นๆ (#user-content-ref-19)(#user-content-ref-35).
3. Optimization of Welding Parameters
3.1 Critical Parameters and Their Effects
| พารามิเตอร์ | Optimal Range | Impact on Weld Quality |
|---|---|---|
| อินพุตความร้อน | 1.5–2.5 kJ/mm | Excessive input causes HAZ embrittlement (#user-content-ref-13). |
| อุณหภูมิ | ≤150° C | Prevents carbide precipitation (#user-content-ref-20). |
| Travel Speed | 50–90 mm/min | High speed reduces dilution but risks lack of fusion (#user-content-ref-21). |
3.2 กรณีศึกษา: TIG Welding Parameter Optimization
A study on API 5L X-65 cladded UNS N08825 demonstrated:
- Optimal Parameters: 110 ก, 12 วี, 70 mm/min.
- Results:
- Tensile strength retention: 99.2% of base metal.
- Impact toughness in HAZ: 88–258 J (#user-content-ref-16).
4. Welding Defect Prevention and Control
4.1 Common Defects and Mitigation Strategies
| Defect Type | Causes | Preventive Measures |
|---|---|---|
| แคร็กร้อน | Low-melting eutectics, stress | Use low-sulfur filler metals; preheat (100–150°C) (#user-content-ref-31). |
| ความพรุน | Moisture, contaminated shielding | Ensure gas purity (>99.995%); avoid drafts (#user-content-ref-35). |
| Lack of Fusion | Insufficient heat input | Increase current; reduce travel speed (#user-content-ref-36). |
4.2 Quality Assurance Standards
- ASTM B705: Specifies dimensional tolerances and mechanical testing for welded pipes.
- ไอเอสโอ 5817: Defects classification (Level B for critical applications) (#user-content-ref-28)(#user-content-ref-30).
5. การรักษาความร้อนหลังการเชื่อม (สวท)
5.1 Requirements and Procedures
- Typical PWHT: 600–650°C for 1–2 hours to relieve residual stresses.
- Exceptions: Austenitic structure of UNS N08825 generally avoids PWHT unless specified for high-temperature service (>538องศาเซลเซียส) (#user-content-ref-38)(#user-content-ref-42).
5.2 Microstructural Considerations
- Carbide Precipitation: Minimized by rapid cooling (water quenching) post-PWHT.
- Stabilization Treatment: 885°C for 1.5 hours to enhance intergranular corrosion resistance (#user-content-ref-39).
6. Industry Applications and Case Studies
6.1 น้ำมัน & ภาคก๊าซ
- Subsea Pipeline Welding: TIG root + MIG fill/cap processes achieve X-ray compliance (100% pass rate) (#user-content-ref-12).
- กรณีศึกษา: ก 2024 project by Sinopec utilized UNS N08825 for sour gas pipelines, reducing corrosion-related failures by 40% (#user-content-ref-43).
6.2 Nuclear Power Applications
- Coolant System Welds: emb (การเชื่อมลำแสงอิเล็กตรอน) achieved 600 MPa tensile strength, matching base metal performance (#user-content-ref-17).
6.3 การแปรรูปทางเคมี
- Acid Reactor Fabrication: SMAW with ENiCrMo-3 electrodes demonstrated 15-year service life in sulfuric acid environments (#user-content-ref-46).
7. แนวโน้มและนวัตกรรมในอนาคต
- การเชื่อมแบบไฮบริดเลเซอร์: Combines laser and MIG for higher speed and deeper penetration.
- การผลิตสารเติมแต่ง: Wire-arc AM (WAAM) for complex pipe geometries with UNS N08825 (#user-content-ref-17)(#user-content-ref-24).
Chemical composition and mechanical properties of UNS N08825 nickel-based alloy
UNS N08825 nickel-based alloy (commonly known as Incoloy 825) is an austenitic iron-chromium-nickel alloy, the main components of which include nickel, โครเมียม, โมลิบดีนัม, copper and a small amount of iron, ไทเทเนียม, aluminum and other elements. Its chemical composition and mechanical properties are as follows:
องค์ประกอบทางเคมี
- นิกเกิล (ใน) : 38%-46%.
- โครเมียม (Cr) : 19.5%-23.5%.
- โมลิบดีนัม (โม) : 2.5%-3.5%.
- ทองแดง (ลูกบาศ์ก) : 1.5%-3.5%.
- เหล็ก (เฟ) : 22%-25%.
- ซิลิคอน (และ) : 0.5%.
- แมงกานีส (มน) : 1.0%.
- กำมะถัน (ส) : 0.03%.
- ฟอสฟอรัส (ป) : 0.03%.
คุณสมบัติทางกล
- ความแข็งแรงของผลผลิต : 725 MPa.
- ความต้านทานแรงดึง : 550 MPa.
- การยืดตัว : ≥30%.
- Brinell hardness : ≤135-165.
- โมดูลัสของความยืดหยุ่น : 28.3 x 10⁶ kN/mm² (196 kN/mm²).
คุณสมบัติ
- ความต้านทานการกัดกร่อน : Excellent corrosion resistance, especially in reducing and oxidizing environments, and performs well against media such as sulfuric acid, phosphoric acid, chlorides and hydroxides.
- ประสิทธิภาพอุณหภูมิสูง : It still maintains good mechanical properties in high temperature environments above 700°C.
- Oxidation resistance : In a high-temperature oxidation environment, the surface oxide layer is thinner, which delays the wear and aging of the material.
- ประสิทธิภาพการเชื่อม : easy to form and weld, and not easily sensitized during the welding process.
โดยสรุป, UNS N08825 nickel-based alloy has been widely used in chemical industry, วิศวกรรมทางทะเล, nuclear industry and high-temperature heat exchangers due to its excellent corrosion resistance and high-temperature performance.
UNS N08825 Common welding process methods (TIG/MIG/SMAW, ฯลฯ)
สหรัฐอเมริกา N08825 (ความไม่สงบ 825) is a nickel-based alloy with excellent corrosion resistance and high temperature performance. It is widely used in petrochemical, วิศวกรรมทางทะเลและสาขาอื่น ๆ. Its common welding methods include TIG (tungsten inert gas welding), ฉัน (การเชื่อมก๊าซเฉื่อยโลหะ) and SMAW (manual arc welding).
- ทีไอจี (Tungsten Inert Gas Welding)
TIG welding is suitable for thin plates and situations where high-quality welded joints are required. This method uses a non-consumable tungsten electrode and inert gas (such as argon) to protect the welding area, which can accurately control the heat input and reduce the structural changes in the heat-affected zone of the weld, thereby improving the welding quality. - ฉัน (Metal Inert Gas Welding) :
MIG welding is suitable for welding medium and thick plates. It can achieve high production efficiency and good welding performance by continuously consuming welding wire and protecting the welding area with inert gas. This method is suitable for thick plate welding, but it requires strict control of welding heat input to avoid structural changes. - สมาว (Manual Metal Arc Welding) :
SMAW is a traditional welding method that is suitable for materials of various thicknesses. This method melts the metal through an arc between the electrode and the workpiece, and the electrode protects the weld area during the melting process. Although the production efficiency is low, it is simple to operate and is suitable for welding small-diameter pipes and base welds.
นอกจากนี้, the following points should be noted during the welding process of UNS N08825 alloy:
- Welding material selection : AWS ERNiCrMo-3 welding wire or electrode is recommended to ensure the corrosion resistance and mechanical properties of the welded joint.
- Welding parameter control : Reasonable selection of welding current, voltage and gas flow to optimize welding quality and reduce defects.
- Post-treatment : For thick plate welding, heat treatment may be required to eliminate stress concentrations and improve the microstructure.
โดยสรุป, there are various welding process methods for UNS N08825 alloy. ทีไอจี, MIG and SMAW are all commonly used methods. The specific selection needs to be considered comprehensively based on the workpiece thickness, welding position and quality requirements.
① Characteristics of heat affected zone of medium material welding
According to the existing data, the research on the characteristics of the heat affected zone (ฮาซ) of UNS N08825 nickel-based alloy welding mainly focuses on the following aspects:
- Welding performance and microstructure :
- UNS N08825 alloy has excellent corrosion resistance and high temperature performance, but its welding process is relatively complicated, and the microstructure changes and welding quality of the welded joint directly affect its performance.
- ในระหว่างการเชื่อม, high nickel content and the distribution of alloying elements have a significant impact on the welding performance and may lead to a decrease in the mechanical properties of the welded joint.
- Microstructure and properties of heat affected zone :
- Studies have shown that the microstructure of the heat-affected zone of welding will change significantly, the grain shape and size will become coarser, resulting in a decrease in the mechanical properties of the material.
- In the Charpy impact test, the minimum impact value of the HAZ area is significantly lower than that of the base material area, indicating that the toughness of the HAZ is poor.
- Influence of welding process on HAZ :
- Different welding methods (such as laser welding, การเชื่อมลำแสงอิเล็กตรอน, ฯลฯ) have different effects on the microstructure and properties of HAZ. Laser welding can improve the mechanical properties and microstructure of the joint.
- Process parameters such as welding heat input, restraint, pre-weld heat treatment and post-weld heat treatment have an important influence on the crack sensitivity and mechanical properties of HAZ.
- Effect of heat treatment on HAZ :
- Reasonable heat treatment process can optimize the structure and properties of HAZ and reduce the sensitivity of liquefaction cracks.
- Appropriate heat treatment at high temperature (such as solution treatment and stabilization treatment) can improve the corrosion resistance and mechanical properties of HAZ.
- Challenges in practical applications :
- In practical applications, the corrosion resistance and mechanical properties of welded joints need to be guaranteed by strict welding process and heat treatment.
- Welded joints in high temperature environments may face the risk of intergranular corrosion and stress corrosion cracking, and special attention should be paid to post-welding heat treatment and anti-corrosion measures.
โดยสรุป, the research focus of the heat affected zone of UNS N08825 nickel-based alloy welding is to optimize the welding process and heat treatment parameters to improve the mechanical properties and corrosion resistance of HAZ and ensure the reliability of welded joints in high temperature and corrosive environments.
②Process parameter optimization plan (current/voltage/speed, ฯลฯ)
To optimize the TIG, MIG and SMAW process parameters (including current, voltage and speed) of UNS N08825 alloy welding to improve welding quality and efficiency, you can refer to the following suggestions:
1. การเชื่อม TIG
- Current : The current directly affects the weld depth and width. For N08825 alloy, it is recommended to control the current between 90 และ 110 A to avoid undercutting and burn-through caused by too small a current, and to avoid excessive weld width caused by too large a current.
- Voltage : The voltage should be controlled between 11 และ 13 V to ensure good arc stability and weld formation quality.
- Speed : The welding speed should be controlled between 50 และ 90 mm/min to obtain good weld formation and lower heat input, thereby reducing welding defects.
- Shielding gas : Use argon or helium as shielding gas to ensure stability and weld quality during welding.
2. MIG welding
- Current : Current has a significant effect on weld penetration and width. The recommended current range is 140~150 A to ensure good weld formation and mechanical properties.
- Voltage : Voltage has an important influence on weld quality and mechanical properties. It is recommended to control the voltage between 20 และ 25 V to optimize the tensile strength and hardness of the weld.
- Speed : The welding speed should be adjusted according to the material thickness and welding position. โดยทั่วไป, the recommended speed is 20~30 cm/min to ensure the uniformity and mechanical properties of the weld.
- Gas flow rate : The protective gas flow rate should be controlled at 15~20 L/min to prevent oxidation and contamination.
3. SMAW welding
- Current : The current directly affects the degree of melting of the weld. It is recommended that the current be controlled between 100 และ 150 A to ensure uniform melting and forming of the weld.
- Voltage : The voltage should be adjusted according to the thickness of the welding material and the welding position. It is generally recommended to control the voltage between 20~25 V to optimize the weld quality and mechanical properties.
- Speed : The welding speed should be controlled at 5~10 cm/min to ensure uniform melting and forming of the weld.
4. Comprehensive Optimization Method
- Taguchi method : Optimizing welding parameters by Taguchi method can effectively improve welding quality and efficiency. ตัวอย่างเช่น, the L9 orthogonal experimental array is used to analyze the effects of welding current, voltage and speed on weld performance and determine the optimal parameter combination.
- Grey correlation analysis : Grey correlation analysis is used to evaluate the influence of different parameters on weld performance and further optimize welding parameters.
- Genetic Algorithm : Genetic algorithm is used for multi-objective optimization to balance welding quality and production efficiency.
5. การโพสต์
- Annealing treatment : Proper annealing treatment should be carried out after welding to eliminate welding internal stress and improve the ductility and plasticity of the weld.
- Solution treatment : Solution treatment is used to optimize the microstructure of the weld and improve its mechanical properties.
6. หมายเหตุ
- ความสะอาด : Ensure the welding environment is pollution-free and remove oxides and contaminants on the surface of the material.
- Shielding gas : Choose appropriate shielding gas, such as argon or helium, to ensure stability and weld quality during welding.
- Heat input control : Strictly control welding heat input to avoid overheating leading to intergranular corrosion and other welding defects.
Through the above methods, the TIG, MIG and SMAW welding process parameters of UNS N08825 alloy can be effectively optimized to improve the welding quality and efficiency.
UNS N08825 Welded Joint Quality Control Standard
The quality control standards for UNS N08825 welded joints are mainly based on the following specifications and standards:
- ASTM B705-05 : This standard is specifically for the specification of welded pipes made of nickel alloys (including UNS N08825), covering the design of welded joints, การเลือกใช้วัสดุ, welding procedures, and quality control requirements.
- ASME BPVC.II.B-2019 : This specification is consistent with ASTM B704-07 and is applicable to the manufacture of UNS N08825 alloy welded pipes, emphasizing the corrosion resistance and mechanical property requirements of welded joints.
- ไอเอสโอ 5817:2015 : This international standard provides general guidance for the quality control of welded joints. It applies to fusion welded joints in nickel-base alloys, including methods for the assessment of defects and the selection of quality grades.
- ASTM B163 and ASTM B423 : These standards specify the chemical composition, mechanical properties and heat treatment process requirements for seamless and welded pipes, ตามลำดับ, and provide technical support for the production implementation of UNS N08825.
- Welding process optimization : To ensure the quality of the welded joint, it is necessary to strictly control the heat input (1.5-2.5 kJ/mm), select suitable welding materials (such as ERNiCrMo-3), and use TIG or MIG technology to reduce the risk of embrittlement in the heat-affected zone.
- Post-heat treatment : การรักษาหลังความร้อนที่เหมาะสม (usually between 600-650°C) is required after welding to optimize the microstructure and improve corrosion resistance.
- Inspection and evaluation : Performance testing of welded joints includes mechanical properties testing, microstructure analysis and corrosion resistance testing to ensure that they meet application requirements.
โดยสรุป, the quality control standards for UNS N08825 welded joints are mainly based on specifications such as ASTM B705-05, ASME BPVC.II.B-2019 and ISO 5817:2015, combined with specific welding process optimization and post-heat treatment requirements to ensure the corrosion resistance, mechanical properties and long-term stability of the welded joints.
②Preventive measures for welding defects (cracks/pores/lack of fusion, ฯลฯ)
To prevent defects such as cracks, pores and lack of fusion during the welding process of UNS N08825, the following measures can be taken:
- Prevention of cracks :
- Control welding stress : Reduce welding stress by preheating and controlling the cooling rate, thereby reducing the risk of cracks.
- Choose appropriate welding materials : Use welding rods or welding wires with a composition similar to that of the parent material to ensure the microstructure and mechanical properties of the welded joint.
- Optimize welding parameters : adjust welding current, voltage and speed to avoid too fast cooling rate and excessive heat input.
- Post-weld treatment : Perform appropriate post-weld heat treatment to eliminate residual stress and improve the performance of the welded joint.
- Prevention of stoma :
- Clean the weldment surface : Make sure there is no oil, สนิม, water or other impurities on the weldment and welding wire surface, especially within 20-30mm on both sides of the groove.
- Choose the right shielding gas : Use high-purity (เช่น 99.996%) argon as the shielding gas to ensure the gas shielding effect during the welding process.
- Control welding speed and current : reduce welding speed and current appropriately to avoid incomplete gas escape caused by too fast welding speed.
- Proper drying of welding rods and flux : Make sure welding rods and flux are fully dried before use to avoid hydrogen porosity caused by moisture.
- Prevention of unfusion :
- Control welding parameters : ensure that the welding current and voltage are sufficient to avoid incomplete fusion due to low current.
- Clean the groove surface : Thoroughly clean the impurities on the groove surface before welding to ensure the cleanliness of the weld edge.
- Adjust welding angle and speed : Properly adjust welding angle and speed to avoid incomplete fusion due to improper angle or excessive speed.
- Comprehensive measures :
- Choose the appropriate welding process : Choose the appropriate welding process according to the specific working conditions, such as short arc operation, stable arc and arc stop, ฯลฯ.
- Strengthen welding inspection : Carry out strict inspection during the welding process to detect and correct defects in time.
- Optimize the welding environment : Keep the welding environment clean and dry to avoid the influence of moisture and impurities in the air on the welding quality.
ผ่านมาตรการข้างต้น, defects such as cracks, pores and lack of fusion during the welding process of UNS N08825 can be effectively prevented to ensure welding quality and corrosion resistance.
UNS N08825 Post-weld heat treatment process requirements
The post-weld heat treatment process requirements for UNS N08825 nickel-based alloy are as follows:
- Necessity of heat treatment :
According to the UNS N08825 nickel-based alloy, post-weld heat treatment is generally not required, but in certain circumstances (such as design documents or technical conditions require), heat treatment is required to eliminate residual stress or improve the performance of the welded joint. - Heat treatment temperature :
If heat treatment is required, the common temperature range is 600-650°C, and the specific temperature needs to be determined according to the design documents or relevant technical conditions. - Heat treatment method :
Heat treatment usually adopts the method of heating in the furnace, including the control of heating rate, holding time and cooling method, ฯลฯ. For long weldments, they can be heated in sections and insulation measures can be taken. - Heat treatment purpose :
The main purpose of heat treatment is to eliminate welding residual stress and improve the structure and properties of the welded joint, thereby improving corrosion resistance and mechanical properties. - บันทึก :
- The welding heat input should be strictly controlled within the range of 1.5-2.5 kJ/mm² to avoid overheating leading to intergranular corrosion or brittle phase precipitation.
- During the heat treatment process, it is necessary to prevent the precipitation of grain boundary carbides, especially the residence time in the sensitization zone (450-800องศาเซลเซียส) should not be too long.
- The hardness value of the weld after heat treatment shall comply with the requirements of the welding procedure specification.
- Special Requirements :
- For environments prone to stress corrosion (such as wet H2S corrosive environment), post weld heat treatment is necessary.
- Standard corrosion testing should be performed after heat treatment to monitor material properties.
โดยสรุป, the post-weld heat treatment process of UNS N08825 nickel-based alloy needs to be formulated according to specific design documents and technical conditions, usually carried out in the range of 600-650°C, with the focus on eliminating residual stress and improving the performance of welded joints.
Related industry application cases (petroleum/chemical/nuclear power, ฯลฯ)
Here are some application cases in the petroleum, chemical and nuclear power industries:
- อุตสาหกรรมน้ำมัน :
- Shengli Petroleum Engineering Company’s “Application of Internet of Things in Petroleum Engineering Equipment Management” project was selected as a typical case of Internet of Things empowering industry development in 2024 by the Ministry of Industry and Information Technology, demonstrating the application of Internet of Things technology in petroleum engineering equipment management.
- Guangzhou Petrochemical has improved the safety and environmental protection indicators of the petrochemical industry through 5G+ information technology, becoming a demonstration case in Guangdong Province and even the whole country.
- Yokogawa provides comprehensive solutions in the oil and gas industry, from the LNG supply chain to downstream oil and gas, covering natural gas liquefaction, การขนส่ง, and regasification.
- Chemical Industry :
- The application of polypropylene pipe (PP pipe) in chemical wastewater treatment, เครื่องปฏิกรณ์เคมี, corrosive liquid transportation and pump station pipelines demonstrates its advantages such as corrosion resistance and high temperature resistance.
- The application of PPH+FRP composite materials in the chemical industry, including PPH+FRP towers, storage tanks and liquid collectors, has improved the performance and safety of chemical equipment.
- Companies such as Xinhua Guangdong Petrochemical and Xinghuo Silicone have applied 5G technology to scenarios such as production unit simulation, equipment predictive maintenance, and global logistics monitoring, promoting the digital transformation of the chemical industry.
- Nuclear power industry :
- China’s nuclear power industrial Internet platform was selected as one of the “Fifth Global Industrial Internet Conference Integration and Innovation Application Cases”, demonstrating the practice of nuclear power digital transformation based on the industrial Internet platform.
- ที่ “Guohe No. 1” demonstration project successfully applied 5G technology, providing the nuclear power industry with smart and information-based modern construction site experience.
- The application of AI technology in nuclear power engineering and test production, including intelligent production and quality control, supply chain management and risk prevention, has significantly improved business efficiency and safety.
ท่อ ERW สีดำ. ความต้านทานไฟฟ้าเชื่อม (ERW) ท่อผลิตจากเหล็กแผ่นรีดร้อน / กรีด. คอยล์ที่เข้ามาทั้งหมดได้รับการตรวจสอบตามใบรับรองการทดสอบที่ได้รับจากโรงงานถลุงเหล็กในด้านคุณสมบัติทางเคมีและทางกล. ท่อ ERW ขึ้นรูปเย็นเป็นรูปทรงกระบอก, ไม่เกิดความร้อน.
ท่อไร้รอยต่อผลิตขึ้นโดยการอัดขึ้นรูปโลหะตามความยาวที่ต้องการ; ดังนั้นท่อ ERW จึงมีรอยเชื่อมในหน้าตัด, ในขณะที่ท่อไร้ตะเข็บไม่มีรอยต่อในหน้าตัดตลอดความยาว. ในท่อไร้รอยต่อ, ไม่มีการเชื่อมหรือข้อต่อ และผลิตจากเหล็กแท่งกลมตัน.
ที่ 3 องค์ประกอบของมิติท่อ ขนาด มาตรฐานของท่อคาร์บอนและท่อสแตนเลส (ASME B36.10M & B36.19ม) ตารางขนาดท่อ (กำหนดการ 40 & 80 ท่อเหล็กหมายถึง) หมายถึงขนาดท่อที่กำหนด (กรมอุทยานฯ) และเส้นผ่านศูนย์กลางที่กำหนด (ดีเอ็น) แผนภูมิขนาดท่อเหล็ก (ตารางขนาด) ตารางคลาสน้ำหนักท่อ (WGT)
ท่อไร้ตะเข็บผลิตขึ้นโดยใช้กระบวนการเจาะ, โดยที่เหล็กแท่งแข็งถูกให้ความร้อนและเจาะจนกลายเป็นท่อกลวง. ท่อเชื่อม, ในทางกลับกัน, เกิดจากการต่อแผ่นเหล็กหรือขดสองขอบเข้าด้วยกันโดยใช้เทคนิคการเชื่อมแบบต่างๆ.
ท่อเหล็กคาร์บอนมีความทนทานต่อการกระแทกและการสั่นสะเทือนสูง จึงเหมาะสำหรับการลำเลียงน้ำ, น้ำมัน & ก๊าซและของเหลวอื่น ๆ ใต้ถนน. ขนาด: 1/8″ ถึง 48″ / ความหนา DN6 ถึง DN1200: ช 20, โรคติดต่อทางเพศสัมพันธ์, 40, เอ็กซ์เอส, 80, 120, 160, ประเภท XXS: พื้นผิวท่อไร้รอยต่อหรือรอย: ไพรเมอร์, น้ำมันป้องกันสนิม, เอฟบีอี, 2วิชาพลศึกษา, 3วัสดุเคลือบ LPE: มาตรฐาน ASTM A106B, A53, API 5L B, X42, X46, X52, X56, X60, X65, บริการ X70: การตัด, บาก, การทำเกลียว, งานเซาะร่อง, การเคลือบผิว, การชุบสังกะสี
ประเภท ก- ใช้ในบริเวณที่มีพื้นที่ส่วนหัวเพียงพอ. ระดับความสูงที่เฉพาะเจาะจงเป็นที่พึงปรารถนา. ประเภทบี- ใช้เมื่อเฮดรูมมีจำกัด. สิ่งที่แนบมากับหัวเป็นแบบดึงเดียว. ประเภทซี- ใช้เมื่อเฮดรูมมีจำกัด. สิ่งที่แนบมากับหัวคือการเชื่อมต่อแบบเคียงข้างกัน
