Double-Side Argon Arc Welding Process for Stainless Steel Tanks

1. Summary of double-sided argon arc welding process

Stainless steel storage tanks typically feature large volumes and thin-walled plates, making them atmospheric vessels. Manual electrode welding is the most commonly used welding process.

However, this welding process can result in significant spatter, internal stress during welding, and substantial deformation on the single side of the weld, making it challenging to control the welding quality.

To address these issues, argon arc welding can be used. This process eliminates spatter and slag during welding, overcoming the shortcomings of manual electrode welding.

Stainless steel has a strong affinity for oxygen, making it susceptible to oxidation at high temperatures. As a result, single-sided argon arc welding primer often leads to the appearance of “slag weld,” resulting in “poor chromium” in the welding joint area and premature failure in corrosive environments.

Furthermore, single-side welding is heavily influenced by groove assembly and can result in welding defects such as incomplete penetration and root fusion.

To address the above defects associated with single-sided argon arc welding and the deformation caused by uneven internal stress, as well as to enhance the qualification rate of NDT film, it is recommended to use the double-sided argon arc welding process. This entails having two people weld both sides of the weld simultaneously.

2. Specific process parameters

1. Weld groove type and size

Welding position

Wall thickness

Groove type

Groove size

interval

truncated edge

groove angle

Longitudinal weld of tank wall

5~8

Single V

1~2

1~2

65~75

Tank wall circumferential weld

5~8

Single V

1~2

1~2

45~55

Note: The groove must be machined before welding. Prior to welding, all pollutants on the surface of the groove and within a 100mm radius must be removed. If necessary, the area should be dried with a dry rag. The alignment and misalignment of the inner weld should not exceed 0.5mm.

2. Welding process parameters

Welding processWelding zoneWelding material specificationPower polarityWelding current (A)Welding voltage (V)Welding speed (mm/min)Argon flow (L/min)
GTAWDouble sided primingΦ2.4positive pole70~10010~1270~11010~14
SMAWFilling coverΦ3.2negative pole90~12020~2460~80/

3. Recommended Welding Materials

1)Argon must be at least 99.99% pure, and a product certificate must be attached to confirm its purity.

2)The recommended welding materials for various austenitic stainless steels are as follows:

Material nameWelding wireFiller rod
0Cr18Ni9(304)ER308 (H0Cr21Ni10)A102
00Cr19Ni10(304L)ER308L (H00Cr21Ni10)A002
0Cr17Ni12Mo2(316)ER316 (H0Cr19Ni12Mo2)A202
00Cr17Ni14Mo2(316L)ER316L (H00Cr19Ni12Mo2)A022
0Cr18Ni10Ti(321)ER347 (H0Cr21Ni10Ti)A132
1Cr18Ni9Ti(321HTB)ER347 (H0Cr21Ni10Ti)A132

Note: Welding materials must have quality certificates or certificates with red seals.

3. Welding diagram

Note: This process has been successfully piloted by relevant companies.

4. Precautions for the application of this process

1)It is important to strictly control the quality of weld groove processing and weld assembly size, including clearance and unfitness.

2)The groove and heat-affected parts should be cleaned and kept dry.

3)The welding process on the main welding side is the same as that of single-sided argon arc welding. The welder on the auxiliary side must work in coordination with the welder on the main welding side and maintain the same welding speed. The wire feeding speed should be adjusted based on the shape of the weld pool and the welder’s experience to ensure that the inner wall weld looks aesthetically pleasing (on the auxiliary side).

4)The specification of the magnetic nozzle of the argon arc welding gun should be selected reasonably based on the thickness of the base metal and the size of the weld groove. The argon flow should be controlled to ensure that the weld pool and heat-affected zone are fully protected.

5)Both welders should start and extinguish the arc at the same time. After welding and extinguishing, argon should protect the arc crater for 1-2 minutes.

6)The wall panel tack welds must be mechanically cleaned before formal welding.

5. Advantages of this process

1)The welding quality is excellent with a high qualification rate on radiographic testing. The weld on the tank wall is also aesthetically pleasing.

2)The welding deformation is minimal, and the external weld on the tank wall is well-crafted.

3)The work efficiency has significantly improved with an increase in labor force in the same working area.

4)Construction costs have been reduced.

By eliminating the need for back welding for argon filling protection, back gouging, and polishing, argon and labor are saved.

6. Disadvantages of this process

1)The welding process has become more challenging, and it now requires welders to work together as a team to maintain a consistent welding speed.

2)Weld alignment standards are stringent, and the clearance for weld alignment is closely monitored.

Don't forget, sharing is caring! : )
Shane
Author

Shane

Founder of MachineMFG

As the founder of MachineMFG, I have dedicated over a decade of my career to the metalworking industry. My extensive experience has allowed me to become an expert in the fields of sheet metal fabrication, machining, mechanical engineering, and machine tools for metals. I am constantly thinking, reading, and writing about these subjects, constantly striving to stay at the forefront of my field. Let my knowledge and expertise be an asset to your business.

Up Next

Mastering CAD/CAM: Essential Technologies Explained

Basic Concepts of Computer-Aided Design and Computer-Aided Manufacturing Computer-aided design and computer-aided manufacturing (CAD/CAM) is a comprehensive and technically complex system engineering discipline that incorporates diverse fields such as computer [...]

Virtual Manufacturing Explained: Concepts & Principles

Concept of Virtual Manufacturing Virtual Manufacturing (VM) is the fundamental realization of the actual manufacturing process on a computer. It utilizes computer simulation and virtual reality technologies, supported by high-performance [...]

Understanding Flexible Manufacturing Systems: A Guide

A Flexible Manufacturing System (FMS) typically employs principles of systems engineering and group technology. It connects Computer Numerical Control (CNC) machine tools (processing centers), coordinate measuring machines, material transport systems, [...]

Exploring 4 Cutting-Edge Nanofabrication Techniques

Just as manufacturing technology plays a crucial role in various fields today, nanofabrication technology holds a key position in the realms of nanotechnology. Nanofabrication technology encompasses numerous methods including mechanical [...]

Ultra-Precision Machining: Types and Techniques

Ultra-precision machining refers to precision manufacturing processes that achieve extremely high levels of accuracy and surface quality. Its definition is relative, changing with technological advancements. Currently, this technique can achieve [...]

Exploring High-Speed Cutting: Tech Overview & Application

Cutting machining remains the most prominent method of mechanical processing, holding a significant role in mechanical manufacturing. With the advancement of manufacturing technology, cutting machining technology underwent substantial progress towards [...]

Top 7 New Engineering Materials: What You Need to Know

Advanced materials refer to those recently researched or under development that possess exceptional performance and special functionalities. These materials are of paramount significance to the advancement of science and technology, [...]

Metal Expansion Methods: A Comprehensive Guide

Bulge forming is suitable for various types of blanks, such as deep-drawn cups, cut tubes, and rolled conical weldments. Classification by bulge forming medium Bulge forming methods can be categorized [...]
MachineMFG
Take your business to the next level
Subscribe to our newsletter
The latest news, articles, and resources, sent to your inbox weekly.
© 2024. All rights reserved.

Contact Us

You will get our reply within 24 hours.