Читать книгу Arc Welding Processes Handbook - Ramesh Kumar Singh - Страница 27

Processes use electrical energy to initiate arc, but not all the arc energy is fully used to melt the metals being welded. There is significant energy loss in the process.

The process efficiency of various arc welding process differs significantly, based on number of factors like material being welded, type of gas being used if gas is used in the process. The effect of these variables depends on one or a combination of more factors.

The use of energy generated by a process is an important factor in determining how much current is needed to generate required heat for welding. The generation of heat also determines the effective use of a process for welding different materials. The table below gives the glimpses of Arc efficiency of various Arc Welding processes.

As is obvious, not all welding and joining process are equal, this leads to the fact that some are more versatile in usability for welding number of materials, while some are more specific to certain type of materials. The table below gives a general usability of various arc welding processes.

For example, GTAW process is nearly all the material listed, but SMAW and SAW processes stops short, and not suitable for welding Copper and alloys, or Titanium and its alloys. Table 1.2 is the generic information, while the Table 1.3 is more specific with numbers and includes more process and varients. Similarly Brazing is possible for nearly all material listed but soldering is not. The Table 1.4 blow presents a matrix that shows the ability and limits of various arc welding processes, the last two columns of the table show the applicability scope of soldering and brazing processes.

The Table 1.5 below is borrowed from another book Applied Welding Engineering – Process, Codes and Standards. The table lists the electric arc process by the arc energy efficiency of each process. Note the highest efficiency of SAW process and the lowest in that of GTW process.

Table 1.2 Arc efficiency by welding process.

	Process	Arc efficiency
1	SMAW	Intermediate
2	GTAW	Low
3	SAW	High