This unit forms part of the Course in MCAST Award in Weldability of Metals and the Management of Engineering Welding. Once a learner complete all the units in this course satisfactorily; that is has obtained a pass mark in the assessment and respected the 80% attendance s/he will achieve an award pegged at MQF Level 5, 20 ECVET Credits
A fabricated weldment should be adequately designed to meet the intended service for the required life. To reach this purpose, it must be fabricated with materials and welds in accordance with approved design concepts. All these factors form an integral part of this unit and learners are given the opportunity to explore weld quality concepts from the point of view of consumables and equipment suppliers and from the point of view of classification societies and the general public.
This unit also covers the duties of welding inspectors, engineers and other members in direct contact with welding operations and the principles of the tests employed to evaluate the adequacies of weldments and their compliance with welding procedures, codes and specifications.
This is a 32 hrs of guided learning course. Students need to invest further hours in the course, which will include private study and home assignments.
Lessons are held as indicated on the prospectus and website.
Learning Outcome 1: Define weld joint quality terminology and the term fitness for purpose quality welds
- Main factors: Service conditions: Stress level, Nature of stress, Working temperature, Corrosion and wear; Material properties: Material of suitable strength, toughness, corrosion resistance; Geometric imperfections: Risk of defects; Consequence of failure: size of weldment, Stored energy, Location, Loss of production; Optimum cost of quality: cost of design, materials, fabrication, quality assurance; Costs of possible failure; service costs including maintenance
- Terminology: Discontinuity, Flaw, Defect, Are strike, Burn-through, Crack, Fissure, Inadequate joint penetration, Incomplete fusion, Overlap, Porosity, Shrinkage void, Slag inclusion, Undercut, Underfill, Defective weld, Acceptable weld
Learning Outcome 2: Describe discontinuities in fusion welded joints and remedies for fusion weld discontinuities
- Weld joint discontinuities: Geometric: Misalignment, Undercut, Concavity and convexity, Excessive reinforcement, Improper reinforcement, Overlap, Burn-through, Backing left on, Incomplete penetration, Lack of fusion, Shrinkage, Surface irregularity;
- Other: Air strikes, Slag inclusion, Tungsten inclusion, Oxide films, Spatter, Arc craters; Metallurgical: Cracks or fissures – Hot, Cold or delayed, Reheat, stress-relief, or strain-age, lamellar tearing;
- Porosity: Spherical, Elongated, Worm-hole;
- Heat-affected zone, microstructure alteration;
- Weld metal and heat-affected zone segregation, Base plate laminations;
- Design related: Changes in section and other stress concentrations, weld joint type
- Causes and remedies for fusion weld discontinuities
- Porosity in fusion welds; Inclusions; Weld metal cracking; Base metal cracking; Slag Inclusion; Incomplete fusion; Inadequate joint penetration; Cracks: Weld metal cracking, Base metal cracking, Surface irregularities
Learning Outcome 3: Evaluate causes and remedies for brazed and soldered joints discontinuities
- Common discontinuities in Brazed joints: Lack of fill, Flux Entrapment, Noncontinuous fillets, Base metal erosion, unsatisfactory surface appearance, cracks
Learning Outcome 4: Define the various roles of Weld Inspectors
- Inspection prior to welding: Procedures and qualifications, Fabrication and testing plans, Base metal specifications and quality, Welding equipment and welding consumables, Joint design and joint preparations;
- Inspection during welding: Conformity to welding procedures and fabrication plans, Preheat and interpass temperature requirements and measurement methods, Filler metal control and handling, Use of welders qualified for specific operations, Interpass and final cleaning, Visual and nondestructive inspection;
- Inspection after welding: Conformity ton drawings and specifications, Cleaning and visual inspection, Nondestructive, proof, and mechanical testing, Repair activities, Postweld heat treatment, Documentation of fabrication and inspection activities
Learning Outcome 5: Categorise standard nondestructive and destructive testing procedures
- Visual inspection with or without optical aids, Liquid penetrant, Magnetic particle, Radiography, Eddy current, Ultrasonic, Acoustic emissions
- Standard destructive testing procedures:
- Chemical Analysis; Mechanical testing: Tension testing, Bend testing, Impact testing, Hardness testing; Metallographic Examination: Macroscopic Examination, Microscopic Examination
- Proof Testing: Load Testing, Hydrostatic Testing, Pneumatic Testing, Spin Testing, Leak Testing, Vacuum Box Testing, Mechanical stress relieving
The following are the suggested pre-requisites and/or entry requirements needed:
- Hand on experience in one or more welding process.
- Knowledge of local Health and Safety Legislation
- Familiar with construction/ industrial sites.
- Level 4 or above in Welding and Fabrication.
- Level 4 in Physics plus industry experience.
Applicants may be called for an interview prior the commencement of the course.
Course participants may be awarded either an MCAST Certificate of Attendance or an MCAST Certificate of Achievement.
MCAST Certificate of Attendance
- An MCAST Certificate of Attendance will be awarded to those candidates who attend at least 80% of the lessons.
MCAST Certificate of Achievement
- An MCAST Certificate of Achievement will be awarded to those candidates who satisfy the 80% attendance criteria AND ALSO choose to sit and pass the course assessment/s.
- Students who opt not to sit for the assessment/s or fail (the assessment/s) will however be awarded an MCAST Certificate of Attendance provided that they fulfill the minimum attendance criteria as stated above.
If the student intends to obtain a Certificate of Achievement, she/he is required to sit for an assessment/s. Assessment/s may take various forms such as a home assignment, class assignment, practical test and time constrained test. However, the assessment/s is not compulsory and an applicant may choose not to sit for it.
There are no additional costs to pay or special materials/equipment to bring