Elements 

Performance Criteria 

Elements describe the essential outcomes.

Performance criteria describe the performance needed to demonstrate achievement of the element.

1. Determine job requirements

1.1 Follow standard operating procedures (SOPs)

1.2 Comply with work health and safety (WHS) requirements at all times

1.3 Discuss corrosion prevention or minimisation need with clients, colleagues and other technical experts

2. Research and determine corrosion prevention or minimisation need

2.1 Identify product performance, cost, location and environmental factors

2.2 Research and report on the metallurgical techniques and principles relating to corrosion from appropriate sources of information and examination of corroded material

2.3 Identify the metallurgical techniques and associated technologies required to prevent or minimise corrosion in the application

3. Determine appropriate corrosion prevention or minimisation strategy and techniques for application

3.1 Select appropriate corrosion prevention or minimisation strategies for application

3.2 Document corrosion prevention or minimisation strategy and approvals obtained from relevant personnel

3.3 Prepare instructions for implementing corrosion prevention or minimisation strategy and communicate to appropriate personnel

This field allows for different work environments and conditions that may affect performance. Essential operating conditions that may be present (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) are included.

Metallurgical principles include:

• definition of corrosion
• environments
• corrosion damage
• classification or corrosion
• cost of erosion
• social implications.

Corrosion principles include:

• electrochemical aspects including:
• electrochemical reactions and chemical corrosion, galvanic cells, anode reactions, cathode reactions, concentrations cells, polarisation, passivity, pourbaix diagrams (simplified Pourbaix diagrams for Al, Fe and Zn), the driving force of corrosion and the rate of corrosion
• environmental effects including:
• oxygen and oxidisers, velocity, temperature, corrosive concentration and corrosion environments (water, soil, atmosphere, dry gasses)
• metallurgical aspects including:
• metal structures (defects, grain boundaries, second phases, cold work, residual stress), galvanic series, immunity and passivity.

Corrosion, mechanism of oxide film growth, at elevated temperatures include:

• rate laws
• oxide defect structures
• Pilling-Bedworth rule
• oxidation of alloys
• catastrophic oxidations
• de carburisation
• high temperature resistant alloys.

Forms of corrosion include:

• uniform corrosion (general corrosion)
• galvanic corrosion
• crevice corrosion
• pitting corrosion
• fretting corrosion
• selective attack (leaching)
• intergranular corrosion
• stray current corrosion (electrolysis)
• erosion corrosion and cavitation damage
• stress corrosion cracking
• corrosion fatigue
• hydrogen damage
• microbial corrosion.

Basic principles of corrosion control include:

• material selection including:
• metals and alloys, metal purification, non-metallics and stress relief
• alteration of environment including:
• changing media, temperature, velocity and oxygen concentration
• corrosion protection including:
• cathodic protection, anodic, protection and passivation, corrosion inhibitors, chemical conversion coatings, metal coatings, corrosion-preventing paints, coatings of plastic and rubber and temporary corrosion prevention
• corrosion prevented by design including:
• wall thickness and design rules (streamlining, stagnation, crevices and metallic contact).

Corrosion characteristics of common alloys include:

• steel and cast iron
• stainless steel
• aluminium and its alloys
• copper and its alloys.

Methodology of corrosion investigations include:

• corrosions testing
• corrosion monitoring
• electrochemical investigations
• physical methods.

Sources of information includes one or more of the following:

• reference texts
• manufacturer catalogues and industrial magazines
• websites
• information gathered using communications technology.