ASTM A335 P91 saluran paip dinding tebal tekanan tinggi Kaedah kimpalan

Kaedah untuk mengimpal saluran paip berdinding tebal tekanan tinggi keluli A335 P91 domestik: bidang teknikal – Ciptaan sekarang berkaitan dengan bidang teknologi kimpalan, khususnya yang berkaitan dengan kaedah untuk mengimpal saluran paip berdinding tebal tekanan tinggi keluli A335 P91 domestik.

Kami mempunyai inventori Terbesar ASTM A335 P91 Alloy Steel Seamless Pipe

Paip Keluli Aloi A 335 P91:

Saiz : 1/2″ untuk 24 “DAN DARI & NB

Jadual: SCH20, Sch30, SCH40.
Jenis : Golek / Direka / LANCAR
Panjang : Rawak Tunggal, Rawak Berganda & Panjang Potong.
akhir : Akhir Biasa, Hujung Serong.

Bahan-bahan :
Paip Keluli Aloi A335 P91 – Paip AS A335 P91
ASTM A335, Gr. P5, P9, P11, P12, P21, P22 & P91

ASTM A335 P91 Komposisi Paip Chrome

Gred	UNS	C≤	MN	P ibu	S ibu	Si≤	Cr	Mo
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
P11	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
P91	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

Piawaian Komposisi Paip A335 Gr P91

Si, %	Cr, %	C, %	Mo, %	MN, %	P, %	N, %	S, %	V, %	Ni, %	NB, %	Al, %
0.2 untuk 0.5	8.0 untuk 9.5	0.08 untuk 0.12	0.85 untuk 1.05	0.3 untuk 0.6	0.02	0.03 untuk 0.07	0.01	0.18 untuk 0.25	0.4	0.06 untuk 0.10	0.04

Jadual Kekuatan Mekanikal Paip ASTM A335 P91

memanjang	Sifat Tegangan	HB	Sifat Hasil
20	585	250	415

Gred Bahan Setara Paip SA335 Gr P91

UNS	ASTM	Bersamaan Bahan	PERSATUAN JURUTERA MEKANIKAL AMERIKA
K91560	A335 P91	K90901, T91, 1.4903, X10CrMoVNb9-1	SA335 P 91

ASTM	PERSATUAN JURUTERA MEKANIKAL AMERIKA	JIS G 3458	UNS	BS	DARIPADA	ISO	ABS	NK	LRS
A335 P9	SA335 P9	STPA 26	S50400	3604 P1 629-470		2604 II TS38

Latar belakang: Keluli A335 P91 ialah keluli 9Cr-1Mo yang diubah suai, terutamanya incorpo

A335P11 A335P91 A335P22 40cr 10CrMO910 35crmo 27SiMn Q345B 16Mn Paip Keluli Aloi Dikimpal

penarafan unsur aloi seperti V dan Nb ke dalam keluli tahan haba martensit 9Cr-1Mo asal. Keluli ini mempunyai rintangan pengoksidaan suhu tinggi yang sangat baik, rintangan kakisan wap suhu tinggi, dan rintangan rayapan, mengurangkan berat struktur dengan berkesan dan mencari aplikasi yang meluas dalam unit dandang yang besar, sistem saluran paip, dan industri petrokimia. bagaimanapun, disebabkan oleh sifat martensit yang disejukkan udara bagi keluli A335 P91, ia mempamerkan keplastikan yang lebih rendah dan kebolehkimpalan yang lebih lemah, mengenakan keperluan yang tinggi pada proses kimpalan, keliatan hentaman sambungan yang dikimpal, kerapuhan kimpalan, rawatan haba selepas kimpalan, dan zon kimpalan yang terjejas haba. Kimpalan keluli A335 P91 tradisional secara amnya menggunakan kimpalan arka tungsten gas manual (GTAW) untuk pas akar dan kimpalan arka logam terlindung manual (SMAW) untuk pengisian dan penutup, necessitating strict control of line energy, preheat temperature, and interpass temperature during the welding process. This method demands a high level of welding environment and welder skill, and manual welding efficiency is extremely low, consuming time and effort, severely restricting piping progress, affecting construction schedules, and particularly evident for large-diameter thick-walled pipelines.

Oleh itu, the rational selection of welding parameters and processes for A335 P91 steel and the development of welding process conditions suitable for production hold significant practical and economic value.

Invention Content: 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, bertujuan untuk meningkatkan kecekapan kimpalan dan kimpalan kualiti, mengurangkan kos pembinaan dan keamatan buruh, dan menambah baik persekitaran kerja.

Bagi mencapai objektif di atas, ciptaan sekarang menggunakan penyelesaian teknikal berikut:

Kaedah untuk mengimpal saluran paip berdinding tebal tekanan tinggi keluli A335 P91 domestik, yang terdiri daripada langkah-langkah berikut mengikut urutan:

(1) Pemprosesan serong pra-kimpalan: Proseskan kawasan kimpalan saluran paip untuk dikimpal menjadi serong berbentuk V berganda, lakukan pemeriksaan penembus pewarna pada permukaan serong untuk memastikan tiada permukaan retak, dan bersihkan serong dan karat permukaan, minyak, dan oksida dalam kawasan 20mm pada kedua-dua belah serong;

Meneruskan kaedah kimpalan untuk paip keluli berdinding tebal A335 P91 yang dihasilkan di dalam negara:

4. rawatan haba selepas kimpalan: Selepas mengimpal, tutup kedua-dua hujung paip dan gunakan pemanas elektrik untuk memanaskan kawasan pada kedua-dua belah kimpalan, sekurang-kurangnya 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:

1. The use of multi-layer, multi-pass welding reduces the cross-sectional area of each weld layer, improving the toughness of the welded joint and avoiding the narrowing of the heat-affected zone in thick welds, as well as the softening of the weld joint during long-term operation at high temperatures.

2. Manual gas tungsten arc welding (GTAW) for root welding has a slower welding speed, and sealing both ends of the pipe helps control the interlayer temperature. Automatic submerged arc welding (MELIHAT) for filling and covering layers has a faster welding speed and higher current, releasing heat more quickly. At least one end of the pipe should be unsealed, and continuous welding can be performed without the need for interlayer temperature control.

3. Using small-diameter welding wires (no more than 2.5mm) and low-hydrogen flux for welding can reduce the linear energy during the welding process, improve the welding deposition rate, refine the base material grains, and reduce the possibility of defects such as porosity and cracks in the weld.

4. In windy environments, the protection effect of automatic submerged arc welding is better than other arc welding processes.

5. Compared to traditional manual welding methods, this method effectively shortens the heat treatment and welding cycle, improves weld kualiti 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, dan lain-lain. 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;b) 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; C) 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;

b) The welding wire should be fed smoothly and evenly, and the welding flux should be added in time to ensure the welding kualiti;

C) 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;

e) 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, slag inclusions, 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, dan lain-lain. 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; b) The welding wire should be fed smoothly and evenly, and the welding flux should be added in time to ensure the welding quality; C) 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; e) 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, slag inclusions, 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.