Welders need to have understanding of the fundamental principles necessary to apply when carrying out weld repairs

• Identify the material type and thereby apply the correct working temperature and consumable selection. 

• Understand the causes of fatigue cracking and know what they can do to minimise re-cracking

• Know how to minimise Residual Stresses

• Know the causes and how to prevent common weld defects 

• Know the importance of keeping Hydrogen content to a minimum 

• Understand the role of susceptible microstructures, residual tensile stress and hydrogen on "cold cracking"

In addition to these fundamental principles, Welder also need to know what methodologies to employ for various Repair Scenarios. 

• There are many considerations that need to be considered depending on the nature and features of the cracking that is to be repaired. 

• By training the Welders to recognise the key factors that need to be considered and best practice approaches to be used for various Repair Scenarios, the Welders can be more autonomous and there can be greater confidence in achieving good repair outcomes. 

Lastly, Welders also need to appreciate the importance of weld quality, and demonstrate ability to self-inspect and objectively assess their welds in order to meet basic Quality Assurance requirements.

• Not every weld can be inspected by an NDT technician or Welding Inspector/Supervisor

• Don't lose efficiency by needing to rework after inspection. 

• It is not possible to inspect quality into a weld after completion - many defects cannot be identified  by post-weld inspection.

For effective repairs of cracking, a Welder must have the skill to produce quality welds in the types of joints that are commonly encountered in repair situations. Furthermore, Welders must be able to do welds that have good fatigue properties. 

• Open root single sided welds, with complete penetration and smooth root profile with minimal notches, have much better fatigue life than repairs made with backing strip

• Weld caps and toes must have a good profile, without sharp valleys or transitions that act as stress raisers

Perhaps most importantly, a Welder must be able to gouge out a crack and do the right preparation to achieve an effective weld repair. 

• Confirm the cracking has been fully removed 

• Properly prepare the weld root without "blowing through" and making an excessive root gap

• Correct prep shape and angles and fully removing all carbon residue from gouging  to ensure the weld is defect free.

Furthermore, Welders also need to know how to "dial in" the correct welding parameters necessary to produce a good weld without needing to refer to a welding procedure or requiring close supervision

• Voltage and Current 

• Wire feed rate 

• Travel speed

• Stick out

• Consumable size and type

• Shielding gas type, flow rate and shroud type.

• Adjust the above as appropriate for the welding position, working temperate and material thickness

There is a clearly defined process for gaining the Mining Welder Competency, which does not affect site or contractor operations

• Welders have the opportunity to be trained and upskilled to meet the required competency level, rather than simply being tested as pass or fail. 

• A "Provisional" Level 3 is assigned based on a simple skill test of being able to do an open root GMAW weld in the overhead position.  If they can't, then they are automatically a "Provisional" Level 2

• The Provisional levels may be applied until such time as the welder completes the required training and full competency assessment

Minimal administration time and costs

• The MWC Certificate is issued by Mining Welder Competency. All records are maintained and freely available via the MWC Portal.  There is no need for mines or contractors to alter their existing systems or develop anything new.

• Mining Welder Competency issue a single certificate on completion. This is all that is required within a site induction management system, without need for complexity of managing multiple records and having to determine whether a Welder meets the competency requirements. 

• Each certificate issued has a QR code on it which can be scanned to view the original document in the MWC Portal to verify the authenticity and currency of the certificate 

• No complex or costly verification or validation system - Employers simply verify that their Welders are still in their employment, have been actively welding, and still does good work. 

• Valid for 3 years. Default renewal method is to go through a refresher training and redo the competency assessment.