Elements and Performance Criteria

RANGE STATEMENT
The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.
Codes of practice/standards
Where reference is made to industry codes of practice, and/or Australian/international standards, it is expected the latest version will be used.
Application
Application refers to any manufacturing, construction fabrication or maintenance process where welding or other thermal process is required and a metallurgical analysis and specification is required either before or after welding or other thermal process is undertaken.
Sources of information
Reference standards and texts
Manufacturers catalogues and industrial magazines
Websites
Use of phone, email and fax for information gathering
Welding techniques and principles include
Weld defect description:
for C/Mn and low alloy steels.
shape defects: excess weld metal, overlap, undercut.
lack of fusion, penetration:incomplete root penetration, lack of root fusion, lack of interrun fusion, lack of side wall fusion.
inclusions: linear, isolated, oxides, .
gas porosity: worm hole, uniform, restart, surface.
solidification porosity: crater pipe, shrinkage porosity.
solidification cracking: hot cracking, lamellar tearing.
hydrogen heat affected zone cracking.
reheat cracking.
weldability of aluminium and its alloys:
inherent problems: hydrogen porosity, oxide, their prevention.
hot cracking: causes, alloys susceptible, alloys resistant, filler metals.
heat affected zone cracking .
welding age-hardened alloys.
welding work hardened alloys.
weldability of carbon and low steels:
the welding zones of steels: identification and microstructures, relation to the iron/iron carbide equilibrium diagram, multi-run welds.
hot cracking: carbon-manganese/sulphur ration.
cold cracking: effect of hydrogen, martensite, stress.
calculation of carbon equivalents
hydrogen content of steel welds and its control.
residual stress avoidence and removal.
calculation of weld preheat temperatures.
tests for cold crack susceptibility.
weldability of stainless steels
stainless steel types.
thermal and electrical conductivity.
thermal expansion.
schaeffler and delong diagrams to predict structures.
austenitic stainless steals: ferrite/hot cracking, corrosion, carbon content/intergranular corrosion.heat affected zone precipitation , carbide stabilisers, extra low carbon stainless.
other special grades: ferritic/ austenitic, martensitic/austenitic.
weldability of cast irons.
special techniques
weldability of the nickel alloys.
filler metals, braze welding
Other thermal processes include:
Cutting, gouging, shaping or local treatment using:
oxy /acetylene
oxy/hydrogen
plasma
carbon arc
Significant figures
Are those relevant to accuracy and are appropriate to the process, data and desired range of results

EVIDENCE GUIDE
The Evidence Guide provides advice on assessment and must be read in conjunction with the Performance Criteria, Required Skills and Knowledge, the Range Statement and the Assessment Guidelines for the Training Package.

Overview of assessment
A person who demonstrates competency in this unit must be able to apply metallurgical principles and techniques in welding. Critical aspects for assessment and evidence are required to demonstrate competency in this unit.
Critical aspects for assessment and evidence required to demonstrate competency in this unit
It is essential that competence is demonstrated in the ability to:
select the most suitable technical and economic welding and other thermal processes for an application
present analysis results and recommendations that are relevant to the product or metallurgical situation
Relationship to other units
This unit may be assessed concurrently with other relevant units.
Assessment method and context
Assessors must be satisfied that the person can consistently perform the unit as a whole, as defined by the elements, performance criteria, skills and knowledge. A holistic approach should be taken to the assessment.
Assessors should gather sufficient, fair, valid, reliable, authentic and current evidence from a range of sources. Sources of evidence may include direct observation, reports from supervisors, peers and colleagues, project work, samples, organisation records and questioning. Assessment should not require language, literacy or numeracy skills beyond those required for the unit.
The assessee will have access to all techniques, procedures, information, resources and aids which would normally be available in the workplace. The method of assessment should be discussed and agreed with the assessee prior to the commencement of assessment.
Resource implications
This section should be read in conjunction with the range of variables for this unit of competency. Resources required include suitable access to an operating plant or equipment that allows for appropriate and realistic simulation. A bank of case studies/scenarios and questions will also be required to the extent that they form part of the assessment method. Questioning may take place either in the workplace, or in an adjacent, quiet facility such as an office or lunchroom. No other special resources are required.