Welding processes
Welding processes used in construction steel structures can be divided into three categories: manual welding, mechanical welding and self-shielding welding.
Manual welding is one of the most commonly used welding processes. It can be used for both mild steel and stainless steel components. To ensure successful welding of steel structures with manual welding processes, several factors have to be taken into account, such as welding procedure, joint preparation, electrode selection, welding position, welding speed, and post-weld cleaning.
Mechanical welding, also known as automated welding, is a method in which components are held in position with a robotic arm. This method is often used for steel structures that require precision and repeatability over a large area. Because of the way the welding is automated, the variables such as joint preparation, electrode selection, welding position, welding speed, etc. remain very constant. This makes the welding process more reliable, faster and more consistent.
Self-shielding welding, also known as cold metal transfer welding, is another type of welding process used in construction steel structures. It is a semi-automated process which requires fewer operators than other welding processes and is also faster and less labor intensive. The process involves a small wire electrode that is fed into the welding arc and melts the metal to form a weld. This welding process produces very good welds with clean, smooth surfaces.
Health and safety
Welding is essential for many construction projects, but the process can pose a significant health and safety risk. It is important that construction workers take appropriate safety precautions before, during and after any welding operations. This includes making sure that their welding masks are correctly fitted, that any welding equipment and materials are in good working order and that the correct safety clothing and foot protection is worn.
Welding also produces hazardous fumes and gases, so workers should take steps to protect themselves. This includes wearing a respirator to reduce the amount of particles and gases that are breathed in, as well as wearing a properly fitting head and face protection to guard against the possibility of sparks or slag entering the workers’ eyes.
Inspection and testing
Once the welding process is complete, it is important to inspect and test the weld for any defects. This is done to make sure that the welded parts meet the required strength and performance criteria and that the structure is structurally sound.
Common defects that are inspected include pitting, cracking, warping, porosity, fusion failure, undercut, and incomplete joint penetration. To ensure that the welds are free of these defects, inspectors will use visual inspection techniques or a variety of non-destructive testing methods such as penetrant testing, magnetic particle testing, ultrasonic testing and radiographic testing.
Conclusion
Welding is a crucial part of many steel structure construction projects, and it is important to understand the different welding processes, the health and safety precautions that need to be taken and the inspection and testing requirements. By being aware of all these factors, workers and construction companies can ensure that their welding processes are effective, efficient and safe.
