CN102152076B

CN102152076B - Process method for manufacturing hot-pressing thick-wall tee joint by performing automatic submerged arc welding on X80-grade steel plate

Info

Publication number: CN102152076B
Application number: CN 201110069621
Authority: CN
Inventors: 韩连新; 祭立柱
Original assignee: HEBEI YUPENG HEAVY INDUSTRY PIPELINE EQUIPMENT MANUFACTURING Co Ltd
Current assignee: Hebei Hengtong Pipe Fittings Group Co ltd
Priority date: 2011-03-23
Filing date: 2011-03-23
Publication date: 2013-01-30
Anticipated expiration: 2031-03-23
Also published as: CN102152076A

Abstract

The invention discloses a process method for manufacturing a hot-pressing thick-wall tee joint by performing automatic submerged arc welding on an X80-grade steel plate, comprising following steps of: (1) selecting a proper X80-grade steel plate; (2) blanking; cutting a raw material into a rectangular blank according to the design size; (3) barrel rolling; rolling the steel plate into a barrel-shaped blank with a planned diameter; (4) welding: adopting a welding wire and a welding agent which are matched with a base material to carry out automatic submerged arc welding on a barrel-shaped blank pipe; (5) hot-pressing forming; (6) shaping, port flattening and size detecting; (7) heat treatment; (8) performance detection, surface cleaning, nondestructive detection, and end machining; and (9) finished product detection. In the process method, the chemical components of the raw material are designed optimally, so that the material has the advantages of finer grain size, higher strength and lower welding crack sensitive coefficient; the proper welding wire and the welding agent are selected, heat input amount in welding is controlled, therefore deposited metal with better toughness is obtained; and since proper temperature is selected for hot forming and heat treatment, the very fine bainite structure is formed; and finally, a finished high-quality tee joint product which conforms to the standard and is suitable for being butted with a trunk pipeline is obtained.

Description

Performing automatic submerged arc welding on X 80-grade steel plate heats presses the heavy wall technological process for three-way

Technical field

The invention belongs to a kind of processing method of threeway, a kind of performing automatic submerged arc welding on X 80-grade steel plate heats the process of pressing the heavy wall threeway specifically.

Background technology

Current, more and more extensive to the utilization of this clean energy resource of petroleum gas both at home and abroad, the construction of natural gas line conveying engineering progressively enters the peak period.For improving pipeline transmission capacity, use the dominant direction that high grade of steel pipeline has become pipe-line construction.At present, the X80 steel-grade pipeline is successful Application in China's the second west to east gas pipeline project pipeline engineering is built, because X80 steel-grade heavy caliber steel plate tubulation accessory belongs to first Application, therefore, the welding procedure in its manufacturing process is all manual electric arc welding.But, manual electric arc welding has the following disadvantages: the one, and manual electric arc welding requires high to welding welder's technical merit and working attitude, the level of enforcement of welding procedure directly affects the inherent quality of weld seam, only depend on Non-Destructive Testing can not guarantee the obdurability of weld seam, this is a bad destabilizing factor that overcomes.The 2nd, the outward appearance of manual electric arc welding weld seam is not attractive in appearance, and the open defect such as need the reconditioning undercut, splash can cause destruction and attenuate to mother metal like this.The 3rd, manual electric arc welding labour intensity is large, and production efficiency is low.

Summary of the invention

The present invention's purpose is to overcome the above-mentioned deficiency of prior art, provides a kind of improved X80 grade steel plate to heat the process of pressing the heavy wall threeway, adopt Lincoln weld, easy to operate, labour intensity is low, good product quality, good looking appearance can reach the requirement of standard code.

In order to achieve the above object, the present invention takes following process:

1. in conjunction with the chemical composition of the female pipe of main line and according to pipe fitting production technology characteristic, the raw material chemical composition is designed, select suitable X80 grade steel plate, its CEpcm≤0.25%, C content are 0.07-0.10%, and Mn content is 1.5-1.85%, Si content is≤0.5%, Cr content is that≤0.45%, Mo content is that≤0.35%, V content is≤0.13%, Ni content is≤1.0%, Nb content is that≤0.10%, Cu content is≤0.35%, and its grain size control is more than 11 grades;

2. blanking: raw material are slit into rectangular billet by design size;

3. reel: the tubular blank of roll of steel plate being made the plan diameter;

4. welding: the welding wire of employing and mother metal coupling and solder flux carry out Lincoln weld to the longitudinal joint of tubular base pipe, the control welding pre-heating temperature is 200 ℃ ± 10 ℃, interlayer temperature≤150 ℃, and control welding current≤470A, adopt the single track multilevel method control welding machine speed of service 〉=30cm/min, guarantee heat input≤24KJ/cm;

5. hot-forming: heating-up temperature≤930 ℃, every time heats pipe charging temperature again and is controlled at below 600 ℃;

6. shaping, flat mouth, size detection;

7. heat treatment: by the even shove charge of standard, weld seam is horizontal, strictly controls Technology for Heating Processing, improve the cooling velocity when quenching, to obtain the higher grain size of rank as far as possible;

8. Performance Detection, removing surface, Non-Destructive Testing, end machined;

9. finished product detection.

The present invention adopts above-mentioned process, have following beneficial effect: the one, the raw material chemical composition is optimized design, by clear and definite diversification low-carbon microalloy composition, material is had than the fineness of grain, higher-strength, lower weld crack sensitivity coefficient, strengthen the loss surplus that in process, causes grain size and intensity because of heating for multiple times, ensured the feasibility of welding material and welding procedure.The 2nd, by the optimization of submerged-arc welding wire and solder flux being chosen the welding material that has obtained with mother metal coupling, and the heat input during strict control welding, obtained having the deposited metal of good obdurability.The 3rd, by the strict control to hot briquetting and heat treatment step, make material in all are heated operation, be in the suitable temperature range, reasonably heating process has limited material crystals disorganization and thick, the complete solid solution of all trace elements is in crystal after the final heat treatment, formed superfine bainite structure, make surface and the heart section performance uniformity of finished product mother metal and weld seam, thereby obtain meeting standard and the suitable high-quality threeway finished product that docks with main pipeline.

The specific embodiment

Introduce in detail the present invention below in conjunction with embodiment.

Embodiment: the present invention takes following technique:

1. the raw material chemical composition is designed, select suitable X80 grade steel plate, its carbon equivalent Pcm is 0.23%, C content 0.10%, Mn content are that 1.54%, Si content is 0.26%, Cr content is 0.20%, Mo content is that 0.25%, V content is that 0.051%, Ni content is 0.36%, Nb content is 0.059%, Cu content is that 0.15%, P content is that 0.01%, S content is 0.001%; Its grain size is 11.5 grades;

2. blanking is slit into rectangular billet to raw material by design size;

3. reel utilizes large-scale rolling machine roll of steel plate to be made the tubular blank of plan diameter;

4. the welding wire (H08MnNi) that welding is adopted and mother metal mates and solder flux (model is BJ-SJ101-G) carry out Lincoln weld to the longitudinal joint of tubular base pipe, the control welding pre-heating temperature is 200 ℃ ± 10 ℃, interlayer temperature≤150 ℃, and control welding current≤470A, adopt the single track multilevel method control welding machine speed of service 〉=30cm/min, guarantee heat input≤24KJ/cm;

5. hot-forming heating-up temperature≤930 ℃, every time heats pipe charging temperature again and is controlled at below 600 ℃;

6. shaping, flat mouth, size detection;

7. heat treatment: by the even shove charge of standard, weld seam is horizontal, strictly controls Technology for Heating Processing, the cooling velocity that as far as possible improves when quenching reaches 500 ℃/min, to obtain the grain size of rank 〉=10 grade;

9. finished product detection.

In the technique of the present invention, guaranteeing to reduce welding current under the prerequisite that weld metal fully merges, improve speed of welding, the restriction heat input is for finished product provides performance consistent base pipe; Strictly controlled all and product has been had the manufacturing procedure of heat input, in processing range, select lower limit temperature to carry out to improve firing rate as far as possible and improve cooling rate when quenching as far as possible, effectively control the leading indicator of this embodiment steel performance of metallic crystalline structure, finally obtained to meet Q/SY GIX106-2010 pipe-line engineering with the product of DN400 and the requirement of above pipe fitting general technical specifications.

Claims

1. a performing automatic submerged arc welding on X 80-grade steel plate heats and presses the heavy wall technological process for three-way, it is characterized in that it takes following steps:

(1) the raw material chemical composition is designed, select suitable X80 grade steel plate, its CEpcm≤0.25%, C content is 0.07-0.10%, Mn content is 1.5-1.85%, and Si content is that≤0.5%, Cr content is≤0.45%, Mo content is≤0.35%, V content is that≤0.13%, Ni content is that≤1.0%, Nb content is≤0.10%, Cu content is≤0.35%, and its grain size control is more than 11 grades;

(2) blanking: raw material are slit into rectangular billet by design size;

(3) reel: the tubular blank of roll of steel plate being made the plan diameter;

(4) welding: the welding wire of employing and mother metal coupling and solder flux carry out Lincoln weld to the longitudinal joint of tubular base pipe, the control welding pre-heating temperature is 200 ℃ ± 10 ℃, interlayer temperature≤150 ℃, and control welding current≤470A, adopt the single track multilevel method control welding machine speed of service 〉=30cm/min, guarantee heat input≤24KJ/cm;

(5) hot-forming: heating-up temperature≤930 ℃, every time heats pipe charging temperature again and is controlled at below 600 ℃;

(6) shaping, flat mouth, size detection;

(7) heat treatment: by the even shove charge of standard, weld seam is horizontal, strictly controls Technology for Heating Processing, the cooling velocity during quenching reaches 500 ℃/min;

(8) Performance Detection, removing surface, Non-Destructive Testing, end machined;

(9) finished product detection.