Welding is a fabrication process that involves joining metals together. After welding, quality assurance is necessary to test the quality of welded material. Many factors that affect the strength and quality of the weld, including:
Materials
Materials have different melting points and chemical compatibility. For a high-quality weld, materials intended for welding must have the same melting point. If the materials have different melting points, one metal will begin to degrade before the other has softened. Ideally, materials with low and medium melting points are preferable for welding. The materials must also be chemically compatible. Other factors, such as colour and pigmentation of the material, will affect the weld's quality.
Welding process
There are a few welding processes that utilise either electricity or gas to achieve melting. These welding processes transmit different amounts of energy that play a role in weld quality. Excessive heat may melt and degrade the material, while too little energy is insufficient for a melt. In addition, specific processes such as stick welding may result in an indentation on the material. As the electrode exerts heat on the material, it causes circular marks that distort the appearance of the final product. While these marks cannot be reduced entirely with stick welding, you can minimise them by reducing welding time. You may also need to perform other processes such as painting to cover the indentations.
Surface condition
The surface condition will affect the quality of the weld. Welding materials with a dirty and greasy surface will make welding difficult. Before welding can begin, surface preparation is necessary to remove any dirt or coatings such as paint. The removal of coatings ensures that the surface area is ready for welding. Dust and other coatings affect weld quality as these impurities may lead to the porosity of the surface and influence the final appearance of weld. Pre-treatments of welding surfaces, therefore, lead to quality welds that are vital for safety in structural components.
Thermal conductivity
As mentioned above, the type of material affects weldability. Some elements have high thermal conductivity and are difficult to weld. These materials require a high amount of energy to achieve a melting point. Your ability to weld these materials will, in turn, be affected by the type of welding process you use. You can manage heat flow depending on materials, welding process and required component size. Materials with high conductivity are better for weld quality as it prevents any distortion during heating.
Contact your local welding services today to learn more.