Common Defects in Welding and Ways To Avoid Them
No matter your level of expertise, every welder will encounter problems with their applications throughout their career. Common welding defects can severely weaken the joints or completely destroy your weld, so you must learn how you can avoid them. These issues can occur during any stage of the process. Keep reading to understand these defects and how to prevent them.
Inclusions Within the Weld
Inclusions are also called impurities—contaminants that can weaken the weld if trapped inside during the application. This often occurs during an arc weld, flux-cored, or MIG weld. Slag will form in the molten pool, and if it does not float to the puddle’s surface, it will be trapped inside the bead, causing impurities.
To prevent inclusion, clean the slag from previous welds between passing over other joints. Avoid a low amperage setting on your welding equipment, and ensure you use the proper torch speed and angle. If you’re not prepping or cleaning the base metal before you begin, this could also allow more impurities to form.
Porosity Within the Weld
Porosity is when gas bubbles form and get trapped inside the weld. This is usually a product of hydrogen, carbon dioxide, or steam. This defect will weaken the joint if the bubbles do not escape the molten bead.
Avoid this by using a suitable electrode alloy with the proper coating. You could also be moving the torch too fast to create a molten puddle, so try slowing down your movements, and don’t use a long arc.
Cracks On the Weld
One of the most prominent and common problems with welding is when cracks begin to form and grow. Three types of cracks can occur: longitudinal, transverse, and crater. Longitudinal cracks run parallel to the length, and transverse run across the width. Crater cracks usually happen near the end of the application when you terminate the arc and a dent or crater forms.
To avoid this common welding defect, ensure you choose the correct alloy filler for the metal you’re welding. Preheating the joint before the application can also help prevent cracking. Do not use low currents while traveling at high speeds across the joint, or you can cause premature cracks.
Burn-Through on the Weld
Burn-through is precisely what it sounds like. When you apply too much heat to your application, you can burn a hole through the metal. When a hole melts through the joint, it destroys your weld. This is likely to occur when the gap between pieces is too large or you’re moving the torch too slowly.
If you’re using a smaller wire, you could be worsening the issue. Avoid large bevel angles, and do not let the current get too high.
Typically, you can fix or avoid these problems entirely if you utilize the correct high-quality equipment. While this isn’t a complete list, other common defects are poor penetration, underfill, excess, and reinforcement. Take your time performing an application and ensure you use the right tools and materials for the job.