A method for welding high-pressure thick-walled pipelines of domestic A335 P91 steel: المجال التقني – The present invention pertains to the field of welding technology, particularly relating to a method for welding high-pressure thick-walled pipelines of domestic A335 P91 steel.
We have Largest inventory of ASTM A335 P91 Alloy Steel Seamless Pipe
Alloy Steel Pipe A 335 ص91:
الحجم : 1/2″ إلى 24 “IN OD & ملحوظة:
الجدول الزمني: SCH20, Sch30, Sch40.
نوع : ملحومة / مختلق / سلس
طول : Single Random, Double Random & Cut Length.
نهاية : نهاية عادي, نهاية مشطوفة.
المواد :
Alloy Steel Pipe A335 P91 – AS Pipe A335 P91
ASTM A335, Gr. P5, P9, ص 11, P12, P21, P22 & ص91
ASTM A335 P91 Chrome Pipe Composition Composition
| الصف | الولايات المتحدة | C≤ | مينيسوتا | P≤ | S≤ | Si≤ | الجمهورية التشيكية | مو |
| P1 | K11522 | 0.10~0.20 | 0.30~0.80 | 0.025 | 0.025 | 0.10~0.50 | - | 0.44~0.65 |
| P2 | K11547 | 0.10~0.20 | 0.30~0.61 | 0.025 | 0.025 | 0.10~0.30 | 0.50~0.81 | 0.44~0.65 |
| P5 | K41545 | 0.15 | 0.30~0.60 | 0.025 | 0.025 | 0.50 | 4.00~6.00 | 0.44~0.65 |
| P5b | K51545 | 0.15 | 0.30~0.60 | 0.025 | 0.025 | 1.00~2.00 | 4.00~6.00 | 0.44~0.65 |
| P5c | K41245 | 0.12 | 0.30~0.60 | 0.025 | 0.025 | 0.50 | 4.00~6.00 | 0.44~0.65 |
| P9 | S50400 | 0.15 | 0.30~0.60 | 0.025 | 0.025 | 0.50~1.00 | 8.00~10.00 | 0.44~0.65 |
| ص 11 | K11597 | 0.05~0.15 | 0.30~0.61 | 0.025 | 0.025 | 0.50~1.00 | 1.00~ 1.50 | 0.44~0.65 |
| P12 | K11562 | 0.05~0.15 | 0.30~0.60 | 0.025 | 0.025 | 0.50 | 0.80~1.25 | 0.44~0.65 |
| P15 | K11578 | 0.05~0.15 | 0.30~0.60 | 0.025 | 0.025 | 1.15~1.65 | - | 0.44~0.65 |
| P21 | K31545 | 0.05~0.15 | 0.30~0.60 | 0.025 | 0.025 | 0.50 | 2.65~3.35 | 0.80~1.60 |
| P22 | K21590 | 0.05~0.15 | 0.30~0.60 | 0.025 | 0.025 | 0.50 | 1.90~2.60 | 0.87~1.13 |
| ص91 | K91560 | 0.08~0.12 | 0.30~0.60 | 0.020 | 0.010 | 0.20~0.50 | 8.00~9.50 | 0.85~1.05 |
| P92 | K92460 | 0.07~0.13 | 0.30~0.60 | 0.020 | 0.010 | 0.50 | 8.50~9.50 | 0.30~0.60 |
A335 Gr P91 Pipes Composition Standard
| الاشتراكية الدولية, % | الجمهورية التشيكية, % | ج, % | مو, % | مينيسوتا, % | ف, % | N, % | S, % | V, % | ني, % | ملحوظة:, % | ال, % |
| 0.2 إلى 0.5 | 8.0 إلى 9.5 | 0.08 إلى 0.12 | 0.85 إلى 1.05 | 0.3 إلى 0.6 | 0.02 | 0.03 إلى 0.07 | 0.01 | 0.18 إلى 0.25 | 0.4 | 0.06 إلى 0.10 | 0.04 |
ASTM A335 P91 Pipes Mechanical Strength Table
| Elongational | Tensile Properties | HB | Yield Properties |
| 20 | 585 | 250 | 415 |
Equivalent Material Grade Of SA335 Gr P91 Pipes
| الولايات المتحدة | ASTM | مقابل المواد | ASME |
|---|---|---|---|
| K91560 | A335 P91 | K90901, T91, 1.4903, X10CrMoVNb9-1 | SA335 ص 91 |
| ASTM | ASME | JIS ز 3458 | الولايات المتحدة | بكالوريوس | الدين | ISO | عضلات المعدة | نك | LRS |
|---|---|---|---|---|---|---|---|---|---|
| A335 P9 | SA335 P9 | STPA 26 | S50400 | 3604 P1 629-470 | 2604 الثاني TS38 |
خلفية: الفولاذ A335 P91 عبارة عن فولاذ 9Cr-1Mo معدّل, في المقام الأول دمج
A335P11 A335P91 A335P22 40cr 10CrMO910 35crmo 27SiMn Q345B 16Mn أنابيب الصلب الملحومة
تصنيف عناصر السبائك مثل V وNb في الفولاذ الأصلي المقاوم للحرارة 9Cr-1Mo. يمتلك هذا الفولاذ مقاومة ممتازة للأكسدة عند درجات الحرارة العالية, مقاومة التآكل بالبخار عند درجات الحرارة العالية, ومقاومة الزحف, تقليل الوزن الهيكلي بشكل فعال وإيجاد تطبيق واسع النطاق في وحدات الغلايات الكبيرة, أنظمة خطوط الأنابيب, وصناعة البتروكيماويات. ومع ذلك, بسبب طبيعة المارتنسيت المبردة بالهواء للفولاذ A335 P91, فهو يُظهر مرونة أقل وقابلية لحام أقل, فرض متطلبات عالية على عمليات اللحام, تأثير صلابة المفاصل الملحومة, هشاشة اللحام, المعالجة الحرارية بعد اللحام, ومناطق اللحامات المتأثرة بالحرارة. يستخدم لحام الفولاذ التقليدي A335 P91 عمومًا اللحام اليدوي بقوس الغاز بالتنغستن (GTAW) لتمرير الجذر ولحام القوس المعدني المحمي يدويًا (SMAW) لملء والتغطية, مما يستلزم رقابة صارمة على طاقة الخط, تسخين درجة الحرارة, ودرجة الحرارة البينية أثناء عملية اللحام. تتطلب هذه الطريقة مستوى عالٍ من بيئة اللحام ومهارة اللحام, وكفاءة اللحام اليدوي منخفضة للغاية, استهلاك الوقت والجهد, تقييد تقدم الأنابيب بشدة, التأثير على جداول البناء, وهذا واضح بشكل خاص بالنسبة لخطوط الأنابيب ذات الجدران السميكة ذات القطر الكبير.
ولذلك, إن الاختيار العقلاني لمعلمات وعمليات اللحام للفولاذ A335 P91 وتطوير ظروف عملية اللحام المناسبة للإنتاج له قيمة عملية واقتصادية كبيرة.
محتوى الاختراع: To address the shortcomings of existing technology, the technical problem to be solved by the present invention is to provide a method for welding high-pressure thick-walled pipelines of domestic A335 P91 steel, aiming to improve welding efficiency and weld جودة, reduce construction costs and labor intensity, and improve the working environment.
To achieve the above objectives, the present invention employs the following technical solutions:
A method for welding high-pressure thick-walled pipelines of domestic A335 P91 steel, comprising the following steps in sequence:
(1) Pre-weld bevel processing: Process the welding area of the pipeline to be welded into a double V-shaped bevel, perform dye penetrant inspection on the bevel surface to ensure no surface cracks, and clean the bevel and the surface rust, زيت, and oxides within a 20mm area on both sides of the bevel;
Continuing with the welding method for domestically produced A335 P91 high-pressure thick-walled steel pipes:
- المعالجة الحرارية بعد اللحام: بعد اللحام, seal both ends of the pipe and use electric heating to heat the area on both sides of the weld, at least 3 times the width of the weld and no less than 25mm. Heat the area to a temperature range of 750-770°C and hold it for 2.5-4 hours, depending on the pipe thickness.
Please note that the temperature in this method is monitored using an infrared thermometer. This welding method for A335 P91 high-pressure thick-walled steel pipes has the following advantages:
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The use of multi-layer, multi-pass welding reduces the cross-sectional area of each weld layer, تحسين صلابة الوصلة الملحومة وتجنب تضييق المنطقة المتأثرة بالحرارة في اللحامات السميكة, وكذلك تليين وصلة اللحام أثناء التشغيل طويل الأمد في درجات حرارة عالية.
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اللحام بقوس غاز التنغستن اليدوي (GTAW) لحام الجذر لديه سرعة لحام أبطأ, ويساعد إغلاق طرفي الأنبوب على التحكم في درجة حرارة الطبقة البينية. اللحام بالقوس المغمور الأوتوماتيكي (رأيت) لطبقات التعبئة والتغطية لديها سرعة لحام أسرع وتيار أعلى, إطلاق الحرارة بسرعة أكبر. يجب أن يكون أحد طرفي الأنبوب على الأقل مفتوحًا, ويمكن إجراء اللحام المستمر دون الحاجة إلى التحكم في درجة حرارة الطبقة البينية.
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استخدام أسلاك اللحام ذات القطر الصغير (لا يزيد عن 2.5 ملم) وتدفق الهيدروجين المنخفض للحام يمكن أن يقلل من الطاقة الخطية أثناء عملية اللحام, improve the welding deposition rate, refine the base material grains, and reduce the possibility of defects such as porosity and cracks in the weld.
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In windy environments, the protection effect of automatic submerged arc welding is better than other arc welding processes.
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Compared to traditional manual welding methods, this method effectively shortens the heat treatment and welding cycle, improves weld جودة and welding efficiency, reduces labor intensity, and saves construction costs.
Implementation example 1: Using domestic A335P91 pipeline DN350 as the base material, the following welding method is adopted:
(1) The welding area of the pipe to be welded is processed into a double V-shaped groove as shown in Figure 1, with a blunt edge height of 1mm, a bottom angle of 60±5° in the direction of the pipe length, a height of 15mm, and an upper angle of 78-82° in the direction of the pipe length. The groove surface is colored inspected to ensure that there are no surface cracks on the groove. The surface rust, oil stains, oxides, إلخ. within 20mm on both sides of the groove are cleaned;
(2) The two sections of the welded pipe are assembled, ensuring that the end face gap of the butt joint is 3-6mm, the height is even, and the misalignment is not greater than 1mm;
(3) Manual argon arc welding GTAW is used for the bottom welding. Before welding, the end ports of the pipe to be welded are blocked, and the inner wall or back of the weld is filled with argon gas for protection. The steel pipe to be welded is preheated, and the temperature of the groove is monitored in real-time using an infrared thermometer. When the temperature reaches 160℃, welding begins, using ER90S-B9 welding wire with a diameter of to weld three layers. The process parameters are selected as follows: DC positive connection of the power supply, welding current of 118A, arc voltage of 14V, and welding speed of 3-10cm/min. Attention should be paid to the following points during manual argon arc welding GTAW: A) The surface of the workpiece to be welded should not be ignited by the arc, tested for current, or temporarily welded to support or clamp;ب) The manual argon arc welding starts from the lowest point of the pipe to be welded, and is symmetrically welded by two people, with the welding joints staggered between 100-150mm; ج) During manual argon arc welding, the preheating temperature on both sides of the groove should be monitored in real-time, and the preheating temperature should be strictly controlled between 150℃ and 200℃; D) During manual argon arc welding, wind protection measures should be taken, and the wind speed in the welding environment should not exceed 2m/s. There should be no draft in the pipe to be welded, and moisture, rain, and snow protection measures should be taken;
(4) Automatic submerged arc welding SAW is used for filling and covering. Before automatic submerged arc welding filling and covering, at least one end of the pipe to be welded is unblocked, and the welding area is preheated. When the temperature reaches 200℃, continuous welding begins, using EB9 welding wire with a diameter of and MARATHON543 welding flux for multi-layer and multi-pass filling and covering welding. The SAW welding parameters are selected as follows: DC reverse connection of the power supply, welding current of 280A, arc voltage of 28V, and welding speed of 25-45cm/min.
Attention should be paid to the following points during automatic submerged arc welding SAW:
A) The welding wire should be kept clean and dry, and the welding flux should be stored in a dry place to prevent moisture absorption;
ب) The welding wire should be fed smoothly and evenly, and the welding flux should be added in time to ensure the welding جودة;
ج) The welding speed should be stable, and the welding gun should be kept perpendicular to the pipe axis to ensure the consistency of the weld bead;
D) The welding slag should be removed in time after each layer of welding is completed, and the surface of the weld should be cleaned with a wire brush or grinding wheel to ensure the quality of the next layer of welding;
البريد) The welding process should be monitored in real-time, and the welding parameters should be adjusted in time according to the actual situation to ensure the welding quality. After the welding is completed, the weld surface should be inspected visually and by non-destructive testing to ensure that there are no defects such as cracks, pores, شوائب الخبث, and incomplete penetration. Finally, the welded joint should be heat-treated according to the process requirements to eliminate welding stress and improve the mechanical properties of the welded joint.
Implementation example 2: Using imported A335P91 pipeline DN500 as the base material, the following welding method is adopted:
(1) The welding area of the pipe to be welded is processed into a double V-shaped groove as shown in Figure 1, with a blunt edge height of 1.5mm, a bottom angle of 60±5° in the direction of the pipe length, a height of 20mm, and an upper angle of 78-82° in the direction of the pipe length. The groove surface is colored inspected to ensure that there are no surface cracks on the groove. The surface rust, oil stains, oxides, إلخ. within 20mm on both sides of the groove are cleaned;
(2) The two sections of the welded pipe are assembled, ensuring that the end face gap of the butt joint is 4-8mm, the height is even, and the misalignment is not greater than 1.5mm;
(3) Automatic submerged arc welding SAW is used for bottom welding. Before welding, the end ports of the pipe to be welded are blocked, and the inner wall or back of the weld is filled with argon gas for protection. The steel pipe to be welded is preheated, and the temperature of the groove is monitored in real-time using an infrared thermometer. When the temperature reaches 200℃, welding begins, using EB9 welding wire with a diameter of and MARATHON543 welding flux for multi-layer and multi-pass filling and covering welding. The SAW welding parameters are selected as follows: DC reverse connection of the power supply, welding current of 350A, arc voltage of 32V, and welding speed of 25-45cm/min. Attention should be paid to the following points during automatic submerged arc welding SAW: A) The welding wire should be kept clean and dry, and the welding flux should be stored in a dry place to prevent moisture absorption; ب) The welding wire should be fed smoothly and evenly, and the welding flux should be added in time to ensure the welding quality; ج) The welding speed should be stable, and the welding gun should be kept perpendicular to the pipe axis to ensure the consistency of the weld bead; D) The welding slag should be removed in time after each layer of welding is completed, and the surface of the weld should be cleaned with a wire brush or grinding wheel to ensure the quality of the next layer of welding; البريد) The welding process should be monitored in real-time, and the welding parameters should be adjusted in time according to the actual situation to ensure the welding quality.
(4) Automatic submerged arc welding SAW is used for filling and covering. Before automatic submerged arc welding filling and covering, at least one end of the pipe to be welded is unblocked, and the welding area is preheated. When the temperature reaches 250℃, continuous welding begins, using EB9 welding wire with a diameter of and MARATHON543 welding flux for multi-layer and multi-pass filling and covering welding. The SAW welding parameters are selected as follows: DC reverse connection of the power supply, welding current of 450A, arc voltage of 36V, and welding speed of 25-45cm/min. After the welding is completed, the weld surface should be inspected visually and by non-destructive testing to ensure that there are no defects such as cracks, pores, شوائب الخبث, and incomplete penetration. Finally, the welded joint should be heat-treated according to the process requirements to eliminate welding stress and improve the mechanical properties of the welded joint.
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