As an NDE technique, In-situ Metallography is ideal for assessing the remaining life of power and petrochemical plants. TCR Arabia has 4 qualified and experienced field services team that regularly conducts In-situ Metallography on-site at major plants, refineries and process industries. This team from TCR determines in-service degradation of critical components of process plants operating under high temperature/ high pressure/ corrosive atmosphere. The technique enables real-time component condition monitoring and health assessments.
In-situ Metallography and replication is used for microstructural analysis when examining large components that cannot be easily moved or destructive sample preparation is difficult or not permissible. In-situ Metallography allows for quick on-site evaluation of a component's metallurgical and heat treatment condition and assist investigators when carrying out a remaining life assessment study or a failure analysis project.
The TCR Advantage - Experienced Metallurgists
The Metallurgists at TCR Arabia in Saudi Arabia have strong experience in the interpretation of microstructure. The Metallurgists have an experience of more then 18,000 replica microstructures and past experiences are well captured into a database. This data base comprises of various plants and information is collected over a different length of time. It also includes a rare collection for different level of damage in the microstructure for power industries/petrochemical/fertilizers and other process industries.
The team is highly skilled in the preparation of the replica. This is more of an art then technique as it is very important to differentiate between the artifacts and the actual defects in the microstructure interpretation.
Codes and Standards
ASTM E3: Preparation of Metallographic Specimens
ASTM E7: Terms relating to Metallography
ASTM E407: Standard for Microetching Metals and Alloys
ASTM E1351: Field Metallographic Replicas
After carefully reviewing and accumulating all knowledge about the operating conditions and stress analysis of the component, the inspectors from TCR Arabia carefully choose a location of the component for in-situ Metallography. This location (area) is polished using custom TCR-developed tools (portable grinding machine or by electrochemical means) and then etched in a suitable medium. Portable microscopy is then performed to ensure that a good clean etch has been established. Onto this etched surface, a sheet of acetate type film is placed and partially dissolved with a solvent. The etched structure is then imposed on the acetate film as a replica image. The acetate is removed from the surface and secured to a glass microscope slide.
Observations can be made both in the field as well as at the laboratory. For field use, a portable microscope (400X magnification) is used to observe prepared metal surfaces and the quality of the replica. A portable microscope with photographic capabilities can also be used to provide digital or positive prints of the examined areas.
At the laboratory, detailed microscopic examinations are made, including digital photographs to document the microstructures collected in-situ. TCR Arabia has access to creating images of Metallurgical replicas on a scanning electron microscopes (SEM). The Microstructure Characterizer Software developed by TCR, assists analyzing the image to determine the microstructural degradation due to creep and calculates the graphitisation, depth or width of Decarburisation, Phase/Volume percentage, grain growth, Inclusion Rating, Particle Size and volume percentage, Particle Count, Porosity and Coating thickness.
TCR Arabia has custom developed special purpose in-situ polishing devices which assist to enable metallographic polishing in difficult locations and allows the field services team to carry out high quality replication even on warm components.
TCR Arabia can also develop a data bank of critical components of equipment of process plant by periodical monitoring for preventive maintenance and planning for inventory control. TCR can provide suggestions on repair welding of used components of process plants.
Metallurgical Replication, Observation and Interpretation
TCR Arabia adheres to the guidelines presented in ASTM E 1351 (Standard Practice for Production and Evaluation of Field Metallographic Replicas). Replicas are developed with or without gold sputtering and analyzed by our team. Using the replication methods our experts can verify microstructures of a given component.
At TCR we have multiple sets of the following In-Situ Metallography kits/equipments:
- Insipol 2000 and advanced electrolytic flow type polisher and etcher
- Portable rough grinder with self adhesive papers
- Portable fine polishing (mini grinder)
- Portable microscope capable up to 400X magnification
- Replica kit, we use specialized plastic based slides for replica preservation which has longer durability and easy to handle at site.
- We have 5 teams comprising of expert Metallography technicians capable to deliver quality and satisfactory services.
Information requested for replica interpretation
- Objective of In-situ Metallography - Condition assessment, fire/damage assessment, remaining life assessment, or base line data generation
- Material of construction with exact specification
- Location of replication with sketch
- Process parameters and design parameters
- Service life of the component at the time of replication.
- Any history of previous failures at the location of replication.
Documentation And Reporting Of Test Results
Each examination shall have the following:
Report no., TCR job no.
Client name, Project ID and Location
Item under examination.
Identity of replica sample.
Micrograph observations, including magnification and comments.
Photographic or similar location device to indicate from where replica taken.
Date of examination.
Technician undertaking procedure.