NDT Consultancy

NDT Training Courses

Penetrant Inspection

Etch Inspection

Magnetic Particle Inspection

Ultrasonic Inspection

Radiography, Digital Radiography

Eddy Current Inspection

Level III Training

Training Calendar

Information for Students

Etch Inspection Training Course Syllabus   -   Level I

1. ETCH INSPECTION-THE PROCESS AND ITS HISTORY
An overview of the development of Etch Inspection of metals from mid 18th Century to the implementation of the method by the Aerospace Industry

2. DEVELOPMENT OF THE PROCESS
The development of the process and structure relationships in steels. The relevance of the process to high integrity aerospace components. Applicability to materials other than steels.

3. MATERIALS COVERED BY THE PROCESS
Low and medium alloy, carburising/ nitriding and maraging steels, copper, bronze and chromium plated steel components.

4. METALLURGY AND HEAT TREATMENT
The iron-carbon and iron-nickel binary phase diagrams and CCC diagrams and their significance to inspection.
Principles of heat treatment including through hardening and tempering, solution treatment and ageing, induction hardening and surface hardening techniques such as carburizing and nitriding
Hydrogen embrittlement and stress relieving/de-embrittlement process.

5. ETCH TECHNIQUES AND THEIR LIMITATIONS
Pre-cleaning methods and their importance. The importance of inter-stage washing. Immersion techniques using dilute Nitric Acid in water or methylated spirit. Post etch alkaline neutralizing and Hydrochloric Acid de-smutting process. The use of de-watering oil to prevent corrosion and to aid inspection. The problems with multiple etching- hydrogenation, loss of finish and dimensions. Pre-etch stress relieving and post-etch de-embrittlement. The use of non-acidic de-smutting agent

6. PROCESS CONTROL AND HEALTH AND SAFETY REQUIREMENTS
Analysis and replenishment of etch solutions, Agitation and temperature control. Verification of etch facility using standard test pieces. Corrosive nature of acids and acidic solutions and their effects on human tissue. Provision and use of safety clothing and eye protection. Methods of making up acidic solutions.
 

Etch Inspection Training