Specialized Metallography Service

Metallography
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Specialized

Metallography

service is one of the strong points of TCR and is the area in which TCR has always worked upon and done extensive research work. One such service is colour metallography. TCR possesses distinct expertise in determination of various phases in the microstructure of a material using colour etching technique, also commonly known as 'tint etching'. Such etching has been used to colour the phases present in many alloys such as cast irons, steels, stainless steels, nickel-base alloys, copper- base alloys, etc. for their phase identification. Colour metallography is a useful method for characterizing microstructures of steel with multiple phases.
However, the accuracy of this method depends on the metallographer's ability & skill to reveal the microstructural constituents of a specimen with sufficient contrast to allow rapid identification either by manual techniques or through the use of an automated Image Analyser. More than the science, colour metallography is an art for developing the microstructure that can discriminate the phases from each other and TCR's metallographers own this skill. TCR's Metallurgists have vast experience in the interpretation of colour metallographs on account of extensive research work in this field. TCR has developed specialized polishing and etching techniques that can develop perfect contrast between the phases and thereby enable a person to distinguish between the phases, precisely.
The following specialized

Metallography

services are rendered by TCR:
  • Colour metallography:
    • To determine percentage of bainite, martensite & ferrite in hardened & tempered steel
    • Delta ferrite percentage in stainless steel weld
    • To measure the ferrite & austenite percentage in duplex stainless steel using point count method
    • Intermetallic phases like chi, laves, sigma etc. in duplex stainless steel
    • Characterization of Cast irons to find out percentage of phases like pearlite, ferrite, graphite nodules, ledeburite, cementite, etc.
    • Primary and secondary carbides percentage in High Carbon-High Chrome (HCHC) steel
    • Retained austenite percentage in hardened & tempered steel
    • Phase identification in copper, brass, aluminium, aluminium bronze alloys etc.
  • Characterization of thermal spray coating using specialized technique as per ASTM E192
  • Characterization of aged structure for rejuvenation purpose using heat-treatment for aged structure
  • Characterization of 'gamma prime' phase in aged gas turbine components
  • Characterization of carbides using Dr. Vogel's reagent for centrifugally cast heater/furnace tubes
  • Characterization of vacuum hardening & sub-zero heat-treated steel for wear resistance properties
  • Macrostructure using NACE TM0498 for finding carburization depth of furnace tubes