Scenario Introduction UK references

To produce a fabricated and welded component requires a significant amount of planning on behalf of the designer and the welding engineer.  Typical discussions between them might include: what material(s) are to be used, what type of welded joint will be suitable, will the welded joint need to be accessed at a later date for inspection purposes, a tricky design dilemma.
You are a qualified fabricator and welder; you have been asked by your foreman to write a report that can be used by possible apprentices as a ‘guide to’:
·Primary arc welding processes
·Production of welded fabrications
The foreman has asked you to use practical examples of the work you have been carrying out as a welder and fabricator to add to your findings.  

Task 4a: (600-700 words) 
Describe the primary arc welding processes. In your response, ensure you include the following:
·Applications (what is this process used on?)
·Operating principles (how does it work?)
Your response must include two of the following processes:
·Manual Metal Arc
·Metal Arc Gas Shielded

Description of the operating principles of both MMA and Mags welding and where are the processes used.
Task 4b: (600-700 words)
Giving the basic facts, identify welding power sources available in the welding workshop that you work in. Your response must include three of the following power supplies:

·Transformer/rectifiers     what are they, what do they do rectifier converts the AC into DC
·Inverter power sources   what are they, what do they do??
·Generators                     what are they, what do they do petrol or diesel engine driven    generator how does it differ from other electrical welding processes

Task 4c: (600-700 words)
Describe typical joint configurations used in welding. (You may wish to use annotated images to help give a clear, straightforward description which includes all of the main points of the joint configurations). 

Images of the joints and descriptions, how they are configured, what joints are used for different material thicknesses.

T fillet
Butt joint, square edge, single V, double V
Lap joint
Open corner

Description of the edge preparation, inclusive angles of joint set-up.
Task 4d: (600-700 words)
Discuss common weld defects, your response must include the following:
·Types of common weld defects
·Causes of common weld defects
·Acceptance criteria, what is acceptable/unacceptable
 
Welding defects associated with:
a)MMA process, slag, inclusion, undercut, lack of fusion, lack of inter run fusion, porosity, uneven leg lengths.
b)Mags process, porosity, lack of fusion, lack inter run fusion, cold lap, uneven leg lengths, undercut.
c)Tig process, porosity, lack of fusion, lack inter run fusion, tungsten inclusion, undercut.

The list is not comprehensive, investigate further!!!

Include pictures to support your answers
 Task 5a: (600-700 words)
Discuss the factors influencing the design of welded joints, your response should include the following:
·Joint configuration 
·Welding position, down-hand, vertical, horizontal and overhead
·Work piece manipulation; the ability to move the structure during welding
·Materials: mild steel, steel alloys, stainless steel.
·In-service behaviour requirements, is the joint subject to shock loading on regular bases.
·Joint access, does the welded joint need to be inspected periodically, ability to access it for inspection. 
Task 5b: (600-700 words)
When a structure has been welded using an electric arc welding process, mechanical changes take place to the area in and around the weld.  These changes will affect the operational performance of the welded joint. Describe the effects of residual stresses on welded structures. 

What happens to the material when it has been welded, heating up very quickly, and cooling down? 

Stress on the welded joint

Task 5c:  (600-700 words)
Discuss the techniques used to control and rectify welding distortion. You will need to describing the methods which are employed to control, or limit the amount of distortion which can take place during the assembly.  When distortion has taken place describe different methods which can be used to rectify, to make good, the distortion, known as post welding rectification. 

Describe distortion, what is it, what happens to metal when it has been welded, change shape.
Task 5d: (600-700 words)
Evaluate the quality control procedures used in welding and fabrication which are in place to ensure the ongoing process of quality control.  From the testing of the welding operative, to the tracking and logging respective weldments, via quality records and site plans, with weldment locations.  

Investigate and describe the process of how a potential welding operative becomes a certified coded welder, including the qualification process and procedure.