Jump to content
Mechanical Engineering
  • entries
    2
  • comments
    8
  • views
    3,256

Differences between Welding, Soldering and Brazing


ibrahim1hj

15,863 views

Differences between Welding, Soldering and Brazing

Welding, Soldering and Brazing are the metal joining process. Each type of joining process has its own significance. Type of joining process to be used for joining two parts depends on many factors. In this article I have covered the differences between the joining processes welding, soldering and brazing.

 
S.No

Welding

 Soldering

Brazing

1Welding joints are strongest joints used to bear the load. Strength of the welded portion of joint is usually more than the strength of base metal.Soldering joints are weakest joints out of three. Not meant to bear the load. Use to make electrical contacts generally.Brazing are weaker than welding joints but stronger than soldering joints. This can be used to bear the load up to some extent.
2Temperature required is 3800 degree Centigrade in Welding joints.Temperature requirement is up to 450 degree Centigrade in Soldering joints.Temperature may go to 600 degree Centigrade in Brazing joints.
3Work piece to be joined need to be heated till their melting point.Heating of the work pieces is not requiredWork pieces are heated but below their melting point.
4Mechanical properties of base metal may change at the joint due to heating and cooling.No change in mechanical properties after joining.May change in mechanical properties of joint but it is almost negligible.
5Heat cost is involved and high skill level is required.Cost involved and skill requirements are very low.Cost involved and sill required are in between others two.
6Heat treatment is generally required to eliminate undesirable effects of welding.No heat treatment is required.No heat treatment is required after brazing.
7No preheating of workpiece is required before welding as it is carried out at high temperature.Preheating of workpieces before soldering is good for making good quality joint.Preheating is desirable to make strong joint as brazing is carried out at relatively low temperature.

 

 

 

 

 

 

 

 

Differences between Welding Soldering and Brazing.pdf

7 Comments


Recommended Comments

Some of your statements are overly broad. For example, you say regarding welding:

 

Work piece to be joined need to be heated till their melting point.

 This leaves the impression that it is necessary to heat the entire work piece to the melting point, when in fact only a small zone near the joint is heated to this extent.

Again, regarding welding you say:

Heat treatment is generally required to eliminate undesirable effects of welding.

While post-weld heat treatment is required in some cases, there are vast numbers of cases where there is no possibility of heat treatment (think of large structures, welding on otherwise finished products, etc). When I add a trailer hitch to my car, the welder attaches the trailer hitch to the car frame, but there is no way to stress relieve the entire car.

Finally, regarding welding again, you say:

 No preheating of workpiece is required before welding as it is carried out at high temperature.

This is simply a non-sequitur, something that does not follow. The fact that welding happens at high temperature does not explain at all why there is no need for preheating. One might easily ask if preheating might make it easier to achieve the required high temperature.

 

Edited by DrD
Link to comment

Ibrahim, while I appreciate reading the many interesting contributions of members, I feel the table you have tabulated is not as good as it could be. You seem to start off your table in a good manner by stating that Welding, Soldering and Brazing are metal joining processes but after that your table becomes rather a little sketchy and over generalised. While brazing is accomplished principally with the oxygen/acetylene torch, and soldering with the iron or flame, welding is divided into four main processes, I say 'main' because while processes such as Friction Welding and Submerged Metal Arc, for example, may be used industrially, they are not in my opinion considered mainstream processes. Manual Metal Arc (MMA), Tungsten Inert Gas (TIG), Metal Inert Gas (MIG) and Oxygen/Acetylene Gas Welding are the most widely used processes by far. Each of these welding processes have their own advantages and disadvantages in joining metal together, but it would be fair to say that each process has its own limitations also. 

In drawing a comparison in your table between Welding, Soldering and Brazing, you have categorised all the many different processes of welding mentioned earlier and summed them up as one process which could easily mislead the reader to say the least. Another thing. What exactly are the 'undesirable' effects of welding? You need to be very precise and specific in order to impart meaningful information. So why not talk about distortion, slag inclusions, Heat Affected Zone (HAZ), undercuts and how they affect the mechanical properties of the weld parent metal. Why not mention that with soft soldering absolute cleanliness is paramount? You could also mention that tinning is a good preparation and that a proprietary flux is very advantageous.     

Also you state that 'no preheating is necessary in welding' because of the high temperatures involved but here again, this statement has fallen victim to your method of categorisation and is incorrect. Consider the welding of cast iron for example. You would need to carefully both preheat and postheat cast iron if cracking at the grain boundaries was to be avoided. 

To my mind welding is a far more complex subject than people give it credit for. It encapsulates not only mechanical engineering and science but metallurgy also. While 'hobby' welding machines very typically flood the marketplace in many countries, the ability to stick two pieces of metal together with them does not necessarily constitute a good weld nor a good welder. There is much more to it than that.  

 

Please accept this as a constructive criticism and not a personal attack   

Edited by Roger A Bailey
Link to comment
On Sunday, August 23, 2015 at 9:59 PM, Roger A Bailey said:

Ibrahim, while I appreciate reading the many interesting contributions of members, I feel the table you have tabulated is not as good as it could be. You seem to start off your table in a good manner by stating that Welding, Soldering and Brazing are metal joining processes but after that your table becomes rather a little sketchy and over generalised. While brazing is accomplished principally with the oxygen/acetylene torch, and soldering with the iron or flame, welding is divided into four main processes, I say 'main' because while processes such as Friction Welding and Submerged Metal Arc, for example, may be used industrially, they are not in my opinion considered mainstream processes. Manual Metal Arc (MMA), Tungsten Inert Gas (TIG), Metal Inert Gas (MIG) and Oxygen/Acetylene Gas Welding are the most widely used processes by far. Each of these welding processes have their own advantages and disadvantages in joining metal together, but it would be fair to say that each process has its own limitations also. 

In drawing a comparison in your table between Welding, Soldering and Brazing, you have categorised all the many different processes of welding mentioned earlier and summed them up as one process which could easily mislead the reader to say the least. Another thing. What exactly are the 'undesirable' effects of welding? You need to be very precise and specific in order to impart meaningful information. So why not talk about distortion, slag inclusions, Heat Affected Zone (HAZ), undercuts and how they affect the mechanical properties of the weld parent metal. Why not mention that with soft soldering absolute cleanliness is paramount? You could also mention that tinning is a good preparation and that a proprietary flux is very advantageous.     

Also you state that 'no preheating is necessary in welding' because of the high temperatures involved but here again, this statement has fallen victim to your method of categorisation and is incorrect. Consider the welding of cast iron for example. You would need to carefully both preheat and postheat cast iron if cracking at the grain boundaries was to be avoided. 

To my mind welding is a far more complex subject than people give it credit for. It encapsulates not only mechanical engineering and science but metallurgy also. While 'hobby' welding machines very typically flood the marketplace in many countries, the ability to stick two pieces of metal together with them does not necessarily constitute a good weld nor a good welder. There is much more to it than that.  

 

Please accept this as a constructive criticism and not a personal attack   

Mr. brahim,  Inclusion of the above Tips in your table will make your article more informative. 

Link to comment
Guest
Add a comment...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Join Mechanical Engineering network

    Join us (login) to get full access : Please sign up to connect and participate.

    To download files...please login






×
×
  • Create New...