Common Welding Issues: How to Correct Them
Posted on May-05-2022
Welding is the process of fusing together two or more parts by the means of heat and pressure. Welding is normally used on metals and thermoplastics. The type of welding that is used can depend on a number of factors, but form and thickness of the material is usually the determining factor.
As welding and technology has developed, welding techniques have simplified. However, it is always possible to forget essential steps when performing welding and it can be hard to diagnose. Here are 5 of the most common welding issues and how to correct them.
Cracks
A crack can be dangerous as they have the potential to become larger as time goes on. Prevention of cracks is much better than trying to correct them as it is not as simple as filling cracks with material. To avoid cracks, it is essential to make sure that the edges of the plates easily fit together. To do this, make sure you spend time on grinding, cleaning and filing the edges. Checking that you have the right amount of heat dialled up and ensuring you reheat both sides of the joint can also help to prevent cracks.
Undercut
There are a number of reasons as to why undercuts may happen; arc voltage is too high, arc being is too long, incorrect electrode usage or angle, if the electrode is too large for the thickness of the plate or travel speed being too quick.
There are multiple ways to prevent undercutting. Watching the speed is always important, but beyond this, it is important to check that the electrode use is being manipulated properly. Additionally, do not use an electrode that is bigger than necessary as an undercut will be created if there is too much molten metal. Lastly, when you are making a horizontal fillet weld, do not hold an electrode near the vertical plate.
Spatter
Spatter is the most common unwanted side effect in gas metal arc welding. Spatter is droplets of molten material produced near the welding arc and are caused when the welding currents are too high, lack of gas shielding or incorrect polarity. To avoid this, check the polarity usage is correct, reduce the welding current and arc length and check the shielding gas type and flow rate.
Porosity
Porosity occurs when the molten weld pool absorbs nitrogen, oxygen and hydrogen. This is then released and trapped in the welded metal once it solidifies. Porosity can be caused when moisture, rust, grease or paint is on the plate edges, lack of gas shielding or when small gaps are being welded but there is still air in between. To avoid this, use fresh welding consumables, check the welding torch for leaks and ensure that the plate edges are clean and dry. Also, check flow rate and the type of shielding gas, clean the gas nozzle and make sure that the angle between the torch and the plate isn’t too big or small.
Incomplete penetration and Fusion
When the weld fails to fuse on one side of the joint in the root, this is an incomplete root fusion. When both sides of the joint in the root are unfused, this is an incomplete root penetration. These problems are more common in processes where the weld metal is deposited automatically when the arc consumes the electrode wire or rod. These processes are often consumable electrode processes such as MIG or SAW. Using a wider root gap or using electrodes whose diameter size is approximately the gap width of the root will typically resolve these problems. Furthermore, using a lower travel speed and weaving between the plate edges will also reduce the likelihood of these issues.
Using Quality Equipment
We have discussed the ways that you can resolve some of the most common issues when it comes to welding. However, having the best and latest welding equipment is always going to make a huge difference in reducing the likelihood of any defects occurring.
Arc Welding Services
Here at Arc Welding Services, we supply a wide range of welding equipment with over 40 years of experience in the industry. We have worked with major clients such as British Rail and Rolls Royce, so rest assured that our expert staff have the knowledge and first class service to help you.
If you are looking for high quality equipment for one off jobs or for ongoing projects, we supply a range of new or used high quality welding equipment making us the perfect company for you. For more information on the services we provide please get in touch on 0121 327 2249 or fill out our online contact form.
