Wednesday, October 22, 2014

Pipe Welding and Filler Metal Considerations

The pipeline industry and pipe metallurgy has evolved over time, giving rise to a great demand for welding processes and products. For this purpose, many multipurpose welding machines with multi process capabilities have been developed with inverter based engine drives. One of the key factors that welders need to determine in welding process pipe is which wires provide the best results for every weld pass. They also need to select the highest quality filler metal. Process piping has its unique requirements and challenges where welders need to comply with strict codes and take precautions to eliminate the risk of defects that could compromise weld integrity. Some welders have moved from gas tungsten arc welding to wire processes. Technologies such as pulsed gas metal arc welding (GMAW-P) have the capacity to increase production and produce the highest quality welds in process pipe applications. One of the major tasks of the welder is to choose the right filler metal.

Types of filler metals

Carbon steel in diameters from 4 to 36 inches is widely used in process piping applications. For the semiautomatic process, the most common diameter is 18 inches or smaller. The filler metal wire options in such applications are solid wire; metal cored wire; and gas shielded flux cored wire. Each type of wire has its unique features and benefits, which must be considered prior to selecting a filler metal for the job. Solid wire is one of the most popular choices since a greater amount of filler metals goes into the weld joint when compared with SMAW electrodes. On the other hand, to speed productivity on process pipe welding applications that use SMAW or GTAW, tubular gas shielded flux cored wire is an ideal alternative. They meet industry mechanical properties such as high strength and side-wall fusion to help reduce weld defects. Metal cored wires, like solid wires can be used with a modified short circuit GMAW process, and allows welders to standardize one wire and gas for the entire application. 
Share:

0 comments:

Post a Comment

Labels