A common problem in welding is when fusion does not occur completely or at all between the welding surface and fusing materials. There are a number of reasons why this happens along with corresponding steps that can be taken to prevent lack of fusion.
Get the correct heat supply
Not enough heat at the point of contact is one of the main reasons why fusion does not occur. This usually means that voltage and current will need to be adjusted to increase the level of heat that is traveling to weld points as you work.
Make sure the edges are lined up properly
The welding material always needs to be properly placed at the edges. This surface also needs to be clear of any debris or contaminants that may prevent clean fusion. A brief or minor oversight in alignment will cause lack of fusion and an imperfect final product.
All beads need to be positioned properly at the welding point. This ensures that when they are melted by the welder they will for a complete seal and avoid a lack of fusion. These gaps that occur from improper bead alignment are often called slots.
Issues during MIG Welding
Some of the main issues that can occur with MIG welding overlap with lack of fusion. Low heat levels or other imperfections on the welding surface will cause improper penetration as well as pores and craters on the welding surface. This can usually be remedied by a faster wire feed output to increase the temperature.
Problems in TIG Welding
Because TIG welding requires each bead to added individually by the welder, it is a more difficult process that is susceptible to defects like lack of fusion. TIG welding defects can include burning through materials, lack of fusion, pores in the metal, and cracking. Tungsten can also get in unwanted places around the welding surface because of its tendency to scatter during TIG welding.
Types of welding defects
All professional welding jobs should be free from cracks in sheet metal, pores around the finished welding area, scattered welding materials left around the surface, improperly fused points, and contaminants from the air. These are all usually signs of poor quality work.
Solve your welding problems today
To learn more about sheet metal fabrication or proper welding techniques, contact Blackstone Advanced Technologies.