Problemas comunes de la soldadura láser manual y sus soluciones

Introducción:

Do you need help with flaws in your handheld laser welding work? Does your welding have cracks, holes, or incomplete fusion? You may have noticed problems with the quality of your work, such as too much spatter or warping. If these laser welding problems are familiar, you are not alone. Check this handheld laser welding troubleshooting guide. We hope your laser welding problem might be one of them.

Although laser welding is fast and accurate, it can have problems leading to known laser welding defects.

This article will highlight the 15 most common handheld laser welding defects. We will explain the reasons for these problems and try to find solutions. So, stay in touch, and let’s get started.

15 Common Handheld Laser Welding Defects and Troubleshooting

There are different reasons why laser welding can go wrong. If this is your first job, you might encounter some problems. These problems happen because of a lack of knowledge, skill, and maintenance.

laser welder welding machine

We will discuss these defects one by one in the following. You will then understand the possible reasons behind them.

Laser Welding Defects #1 Cracking in Welds

Cracking is fractures in the weld bead, often called crater cracks. It poses severe risks to structural integrity. You may frequently find cracks transversely, longitudinally, or at the bead’s end.

There are two types of cracks: hot and cold cracks. Hot cracks generally form when the base metal is heated above 1000 degrees Celsius. On the other hand, cold cracks form due to weather changes.

Reasons:

  • Extreme Joint Strength
  • Improper Welding Techniques
  • Rapid Cooling
  • Improper welding wire material

Laser welding Troubleshooting:

You only need to follow the proper welding techniques. Remember to ensure gradual cooling of the joint. Most importantly, select the appropriate handheld laser welding wire material. Ensure that the welding wire is compatible with the working metal. Popular welding wire materials are aluminum, BeCu, H-13, stainless steel, and P-20. You can also apply pre- and post-weld heat treatment.

Laser Welding Defects #2 Undercut

The undercut looks like a groove or hollow along the welded toe. This laser welding defect generally occurs on the base metal surface. It shows a concave depression next to the weld joint. Eventually, it creates a break that could weaken the weld’s structural stability.

Causes:

Excessive heat is the leading cause of these handheld laser welding problems. Sometimes, these defects may also happen due to incorrect welding speed. When the speed is too high, the liquid metal cannot redistribute. When the liquid metal solidifies, it creates an undercut.

Laser welding Troubleshooting:

  • Correct welding parameters can be the finest laser welding troubleshooting for this issue. Adjust the welding settings and energy density.
  • Make sure you have adequate gas shielding to stop oxidation.

Laser Welding Defects #3 Porosity or Stomata

porosity or stomata

In laser welding, porosity refers to the small holes or bubbles in the welded metal. It is also sometimes called stomata. Porosity usually makes the welds weaker and the structure less stable.

Reasons:

Porosity occurs mainly due to surface contamination. Rapid cooling of the laser welding traps gases generated during the process. This gas primarily forms the pores.

Laser welding Troubleshooting:

  • Clean the base metals before laser welding.
  • Make sure the joints are correctly prepared to keep gas from getting trapped.
  • You can also use back purging methods and adjust the gas flow direction to mitigate this issue.

Laser Welding Defects #4 Overlap

Overlap flaws happen when too much material builds up at the edges of the joint. This extra material can make ridges along the metal’s joint gap. These laser weld problems might look like bumps but could weaken the weld joint.

Reasons:

Low welding speed is one of the most likely causes of overlap flaws. When welding slowly, more molten metal tends to build up.

Laser welding Troubleshooting:

  • Adjust the welding parameters to ensure the correct welding speed.
  • Ensure precise joint fit-up and alignment.

Laser Welding Defects #5 Incomplete Fusion

Sometimes, you may see lines along the weld joint. This situation shows that the materials didn’t correctly fuse. This flaw is usually called incomplete fusion. It happens due to the incompatibility of the filler material, which weakens the bond between the working metals.

Reasons:

One of the main reasons for this laser welding flaw is incomplete penetration. In this case, the mismatch of the filler material is also a crucial reason. Other problems, such as welding too fast or not focusing the laser beam correctly, are worth mentioning.

Laser welding Troubleshooting:

  • First and most importantly, choose the appropriate filler materials.
  • Change the laser’s settings. It makes sure that your laser machine has enough power for welding.
  • Reduce welding speed.
  • Always keep the metal surface clean.

Laser Welding Defects #6 Excessive Splash or Spatter

Spatter or splash is one of the most common handheld laser welding problems that you may often see. It is the expulsion of metal droplets or particles outside the weld region. Spatter or splash creates surface irregularities. It also wastes the filler materials.

Reasons:

The main reason for this problem is the dirty metal surface. The presence of impurities on the workpiece might lead to higher spatter. Spatter can result from severe metal vaporization at high energy density. Incorrect shielding gas and laser settings are also notable.

Laser welding Troubleshooting:

  • Clean the base metal surface. Ensure there are no impurities before welding.
  • Use an appropriate shielding gas. In this case, you should know the proper flow rate and composition to protect the welding pool.
  • Adjust the laser settings for optimal output.

Laser Welding Defects #7 Slag Inclusion

slag inclusion

Slag inclusion can be defined as the entrapment of solid non-metal materials. Examples that come to mind are contaminants, flux, and oxides. You may find dark or uneven lines or pockets in the weld bead. The size and location of these lines or spaces are different. But having them there weakens the purity and strength of the weld.

Reasons:

  • Improper cleaning and the presence of contamination on the surface
  • Excessive welding speed

Laser welding Troubleshooting:

To ensure no contamination, clean the workpieces correctly. However, you can adjust the welding parameters to control speed and penetration. You can grind the metal surface to remove the weld seam with slag inclusions.

Laser Welding Defects #8 Stacked Edge

This laser welding problem is caused by going too fast. When molten metal starts to harden and can’t be adequately redistributed, it forms stacked edges. It also happens due to large joint assembly gaps. You can quickly identify this problem by seeing the formation of a raised edge along the weld.

Reasons:

  • High welding speed prevents proper metal redistribution.
  • Large gaps in the assembly make it harder to get molten metal.

Laser welding Troubleshooting:

  • Optimize power and speed settings. It ensures proper energy distribution.
  • Minimize assembly gap size. It enhances molten metal flow and prevents stacked edge formation.

Laser Welding Defects #9 Deformation

Deformation in welding means that the shape or size of the welded object has changed or been distorted. It typically happens due to thermal stress. Because of this, you may see some changes in the shape or alignment. Common signs include warping, bending, or twisting of the material.

Reasons:

When metals are heated or cooled quickly, they expand and shrink unevenly. These laser welding problems usually happen with thinner materials. Materials that don’t match and have different thermal properties can also cause deformation. Improper fixturing is another cause of this problem.

Laser welding Troubleshooting:

  • Securely hold the workpiece in place.
  • Ensure a controlled cooling system.

Laser Welding Defects #10 HAZ Issues

HAZ stands for Heat Affected Zone. As the name implies, it refers to the area surrounding the weld. HAZ issues may have significant thermal alteration. After welding, you may see some visible distortion or warping. It indicates excessive heat input and thermal stress.

Reasons:

  • Putting in too much heat during welding
  • Not controlling the laser settings correctly
  • Bad choice of materials
  • Not enough cooling

Laser welding troubleshooting:

  • Optimizing laser settings can help you reduce HAZ concerns.
  • You can also use the proper shielding gas and nozzle setup.
  • Select materials with higher thermal conductivity.
  • Improve cooling techniques, such as water quenching or air cooling.

Laser Welding Defects #11 Incomplete Penetration

incomplete penetration

Incomplete penetration is a common laser welding defect. It occurs when the weld seams fail to penetrate the entire thickness. You may often find visible gaps at the root of the weld joint. These defects are a significant cause of incomplete fusion.

Reasons:

  • Insufficient laser power
  • Inappropriate laser welding parameters
  • Material thickness may be more than it should be.
  • Misalignment of the metal parts

Laser welding Troubleshooting:

You can find the correct laser settings for different metal types and thicknesses. Also, ensure the laser beam is focused correctly to penetrate properly. Always make sure that the metal parts are lined up correctly.

Laser Welding Defects #12 Weld Collapse or Sinking

As the name implies, weld collapse or sinking occurs when the center of a weld sinks. You may often see a depression or concavity in the weld bead. This problem not only hampers aesthetics but also structural weaknesses.

Reasons:

Slow welding speed is the primary cause of this laser welding issue. The melt pool becomes large and wide when the welding speed is too slow. As a result, the weld center sinks, causing collapse and craters.

Laser welding Troubleshooting:

  • Optimize welding parameters for proper energy density.
  • Control heat input to prevent excessive melting.

Laser Welding Defects #13 Welding Deviation

This defect refers to the misalignment of the laser welding. How do you find this flaw in laser welding? You can look for shapes that aren’t symmetrical or connections that aren’t lined up with the planned joint paths. It compromises structural integrity and leads to premature failure.

Reasons:

  • Laser optics are not correctly aligned.
  • There’s a vibration during the process.
  • The welding setup may be unstable.
  • You may not have calibrated your device correctly.

Laser welding Troubleshooting:

  • Always ensure the proper alignment of laser optics.
  • Try to find out the cause of vibration in your device. Take the necessary steps to reduce this vibration.
  • Calibrate your machine every time before welding.

Laser Welding Defects #14 Inconsistent Weld Quality

Do you see variations in welds’ appearance, strength, or integrity? Is your laser welding making uneven bead profiles? Do you have varying penetration depths? These are common signs of inconsistent weld quality problems.

Causes:

  • Inconsistent power or energy settings.
  • Changes in the material’s properties or the surface’s state.
  • Bad flow of protecting gas.

Laser welding Troubleshooting:

  • During welding, the power and energy settings stay the same.
  • Keep the material’s features consistent and the surface clean.
  • Calibrate your device often.

Laser Welding Defects #15 Welding Residue

Welding residue is the buildup of unwanted stuff, like sparks or debris, on the weld’s surface or in the area around it. Most of the time, it makes the weld look bad and could even fail to hold together.

Causes:

The main cause of this problem is high laser power or inappropriate parameters. Spatters or splashes are one result. However, contamination of the workpiece is also a cause of welding residue. Moreover, poor gas shielding may allow debris from the air to interact with the welding pool. Finally, oils, rust, or coatings may also interfere with the welding quality and form residue.

Laser welding Troubleshooting:

  • Adjust laser parameters, such as power, speed, and energy density.
  • Clean the surface of the metal.
  • Ensure proper gas flow.

How To Detect Laser Welding Defects?

There are many ways to find welding defects besides just looking at them. These testing methods are standard in the manufacturing business. They usually tell if the welded bead is strong and free of flaws.

Visual Inspection

The simplest and most common method is visual inspection. You can check for cracks, porosity, or irregularities in the weld bead.

Penetrant Testing

In this method, a penetrant solution is applied to the weld surface. This liquid penetrant seeps into the surface-breaking defects. Later, using UV light, the defect can be easily determined.

Ultrasound

You can also use high-frequency sound waves to detect internal defects. This method analyzes defect size, shape, and location.

Radiography

This method uses X-rays or gamma rays to find out the defects. It generally produces an image on a radiographic film. This method is effective for detecting voids, inclusions, or incomplete fusion.

Eddy Current Testing

This method uses electromagnetic induction to detect surface defects. It is great for testing cracks, laps, seams, and voids.

Magnetic Particle Testing

MPT testing is suitable for ferromagnetic materials. This method magnetizes the weld area and applies magnetic particles. When flaws interrupt the magnetic field, particles gather there.

Leak Testing

This method detects leaks in sealed welds. It uses pressurizing the component with a gas or liquid. You can observe the pressure drop. If there is any pressure drop, it means the presence of leaks.

Fillet Weld Break Test

This method involves breaking the weld to check the internal structure. This test reveals incomplete fusion or lack of penetration.

Hardness Test

This method measures the hardness of the weld and surrounding material. It helps you find soft spots.

Frequently Asked Questions

What is the greatest hazard to a welder while laser welding?

UV radiation is the biggest concern when dealing with laser welding. To protect your eyes from these UV rays, wear safety glasses. Traditional methods like MIG or TIG produce metal fumes, posing health risks. However, when dealing with laser welding, you don’t have to worry about that.

Besides, laser welding works with tightly focused light beams, which produce fewer sparks and stray beams. This feature reduces the risk of fire and explosion hazards in the workplace.

Which weld fault is the most serious?

Most people agree that cracks are the worst thing that can happen when laser welding. Under stress, it can spread and finally cause a catastrophic failure. In addition, it may also offer significant safety risks in several industrial settings. So, always ensure you’re using the proper techniques when you weld. Finally, don’t forget to use a suitable filler, such as aluminum, BeCu, or H-13.

What is G in welding?

In welding, “G” typically is the groove weld symbol. It indicates the specific type of weld joint configuration. Square, V, or U shapes are some other weld joint configurations. The groove weld symbol helps welders understand the desired weld shape.

Final Thought

The 15 laser welding defects mentioned above are the most common. However, you need to do two things to eliminate all these defects.

First, adjust the laser parameters. This is a crucial part of your laser welding process. Learn the recommended settings for different materials. You can also contact our customer support to learn more.

Next, prepare your workpiece correctly. Clean it to remove contaminants that can cause defects. You can follow various cleaning methods for this.

If you still find defects, your handheld laser welding device might not suit your job. Therefore, choosing a suitable laser welding machine is crucial. Three primary factors should be taken into account for handheld laser welding.

When choosing a suitable laser welding device, consider your project needs. What type of material will you work with? How about their thicknesses? What kind of weld quality are you looking for? You can choose the right laser power, beam delivery, and control features based on this information.

Next, know about the brands. Always ensure the manufacturer offers the best customer support, like ZL tech. Finally, the cost should be balanced with long-term productivity.

ZL tech laser machine manufacturer

Contact us today for expert advice on laser welding solutions. Let us help you optimize your welding processes. Our team of experts is always happy to assist you.