SHINHOP laser

Traditional welding generally uses argon arc welding, which has been applied for a long time. There are still some small workshops using this type of welding. However, as industrial technology and production quality requirements continue to increase, this traditional welding method can no longer meet the demands of industrial production. Therefore, the emergence of laser welding technology and equipment can effectively address production needs.
So, what are the reasons that lead to laser welding technology replacing tungsten electrode argon arc welding? Below, SHINHOP laser engineers continue to analyze.
1. Weld seam performance.
In basic materials, any technology that produces weld seams has three basic areas: the molten zone, the heat-affected zone, and the transition zone. Due to its rapid cooling rate, laser welding produces narrower weld seams, which is an advantage because it results in less deformation of the base material and lower thermal degradation. However, when welding high carbon steel, rapid cooling can also become a problem, especially when considering subsequent cyclic loads. In this case, the heat-affected zone can become too hard and prone to cracking. This issue can be resolved through careful technical development by selecting the appropriate laser source, determining the focus size, and adjusting other welding parameters. In some cases, preheating or post-weld heating may even be required. Therefore, compared to other technologies, laser welding can better weld "tricky" steels.
High-strength steel used in the construction of lightweight vehicles is all welded using laser welding, thus maintaining its strength and plasticity. This is completely different from conventional welding, which destroys the unique microstructure of these steels and reduces their mechanical properties to the level of ordinary low-carbon steel.
2. Welding speed
Typically, the most important parameter for such production lines is production speed, which is limited by the welding process and the final cutting situation. Let's look at the most common welding beam configuration: connecting 1mm thick materials end-to-end. Using laser welding, it is easy to achieve a welding speed of 10 m/min, which is much faster than conventional TIG welding but slower than induction welding. However, laser welding can also achieve this speed on even thicker materials, mainly depending on laser power and investment budget. Currently, on an already installed production line, laser welding speeds have exceeded 20 m/min.
3. Weld seam quality
Another issue is the quality of the weld seam and its stability during long-term production processes. Generally, laser weld seams have better quality, less surface deformation, and lower oxidation rates. The welding spatter at the root side is limited, and there is even no need to use protective gas underneath. Maintaining consistent welding quality is also one of the most important reasons for choosing laser welding.
However, correctly setting the laser processing technology is much more complex because this process involves a small light spot moving quickly, making it impossible to manually respond to process fluctuations or defects. Equipment suppliers must manufacture welding systems to be as robust and durable as possible to maintain stable and correct settings over the long term, even in harsh industrial environments.
Installing a weld seam quality inspection system is very beneficial because it can check the geometric structure of the weld seam and/or the stability of the welding process. Typically, such systems must learn to recognize the weld seam structure under normal operating conditions, which takes some time. However, afterward, operators can perform 100% instant quality checks, which is a significant advantage and sometimes even a "must."
4. Heat input/Energy consumption
The biggest difference between conventional welding and laser welding is that the overall heat input of laser welding is lower. This result is due to the laser beam creating a narrow welding seam and quickly transferring energy from the beam to the material. We estimated the energy output for welding high-strength steel with a thickness of 1mm, using laser welding, is about 15 J/cm, while conventional welding is at least 60 J/cm, and using melting electrode gas shielded welding is 85 J/cm.
This estimated result is extremely important for calculating operational results and has a significant impact on the mechanical properties of the weld seam, which usually produces better results in laser welding. However, if the rapid cooling of the material or the welding speed is too high, it can also lead to unexpected problems.
5. Protective gas
Laser welding systems are said to only require ordinary xenon gas from above. Helium or mixed gases have certain advantages but are more expensive. This may seem like a minor issue, but the gas prices are extremely important for the overall operating costs of different technologies and even different laser systems.
For ordinary low-carbon steel or stainless steel, there is no need for back protection gas.
6. Operating costs
When comparing the welding of low-carbon steel round tubes with a thickness of 1.5mm, considering energy consumption and other protective costs, excluding depreciation, personnel, and service costs, the results are as follows:
Welding Type              Weld Seam
High-frequency coil welding----------$0.75
TIG welding---------------$0.75
Plasma welding------------$0.75
CO2 laser welding-----------$0.75
Fiber laser welding----------$0.75

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