ADVANTAGES AND DISADVANTAGES OF WELDING

Like all joining processes (in fact, like all processes!), welding offers several advantages but has some disadvantages as well. The most significant advantage of welding is undoubtedly that
it provides exceptional structural integrity, producing joints with very high efficiencies. The strength of joints that are welded continuously (i.e.,full length, without intentional skipped areas) can
easily approach or exceed the strength of the base material(s). The latter situation is made possible by selecting a joint design that provides greater cross-sectional area than the adjoining joint elements and/or filler that is of higher strength than the base material(s). Another advantage of welding is the
wide range of processes and approaches that can be selected and the correspondingly wide variety of materials that can thus be welded.

Advantage of Welding 

Almost all metals and alloys, many (thermoplastic) polymers, most if not all glasses, and some ceramics can be welded, with or without auxiliary filler. Still other advantages of welding are that -

(1) there are processes that can be  performed manually, semi-automatically, or completely automatically; (2) some processes can be made portable for implementation in the field for erection of large structures on site or for maintenance and repair of such structures and
equipment; (3) continuous welds provide fluid tightness (so welding is the process of choice for fabricating pressure vessels);(4) welding (better than most other joining processes) can be performed remotely in hazardous environments (e.g., underwater, in areas of radiation, in outer space) using robots; and (5) for most applications, costs can be reasonable. The exceptions to the last statement
are where welds are highly critical, with stringent quality requirements or involving specialized applications (e.g., very thick section welding).

Disadvantage of Welding 

The single greatest disadvantage of welding is that it precludes disassembly. While often chosen just because it produces permanent joints, consideration of  ultimate disposal of a product (or structure) at the end of its useful life is causing modern designers to rethink how they will accomplish joining.
A prime example is the need for the regulatory authorities in former West Germany to  dismantle the nuclear reactors in former East Germany that have designs similar to the reactor that failed in Chernobyl in the former USSR.

A second major disadvantage of many welding processes is that the requirement for heat in producing many welds can disrupt the base material microstructure and degrade properties. Unbalanced heat input can also lead to distortion or the introduction of residual stresses that can be problematic from
several standpoints.

A third serious consideration, but not necessarily a  disadvantage, is that welding requires considerable operator skill, or, in lieu of skilled operators, sophisticated automated welding systems. Both of these, along with the aforementioned specialized applications, can lead to high cost.

This table summarizes the major advantages and disadvantages or limitations of welding as a means of joining materials or parts into parts or assemblies or structures.

advantages and Disadvantages of Welding
advantages  and disadvantages of welding

Advantages and Disadvantages of Welding as a Joining Process

Advantages
Disadvantages
I. Joints of exceptional structural 
integrity and efficiency, will not
accidently loosen or disassemble 
2. Wide variety of process embodiments 
3. Applicable to many materials within 
a class 
4. Manual or automated operation 
5. Can be portable for indoor or 
outdoor use 
6. Leak-tight joints with continuous welds
7. Cost is usually reasonable
1. Impossible to disassemble joints without 
destroying detail parts 
2. Heat of welding degrades base properties 
3. Unbalanced heat input leads to 
distortion or residual stresses 
4. Requires considerable operator skill 
5. Can be expensive (e.g., thick sections) 
6. Capital equipment can be expensive (e.g., 
welds electron-beam guns and vacuum
chambers) 



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