After undergoing a solution heat treatment (air quenched) and full annealing heat treatment on my stainless steel samples it was observed the hardness of full annealed samples is more than air quenched samples, whereas according to literature is should be opposite, what could be the probable cause?
The reason may be atmospheric gas absoption in case you have done heat treatment without any shielding.
Check their microstructures.( light microscope can give you more information)
What are the hardness values you have got, and how many readings were taken? It is entirely possible that the error you get is within statistical error limits.
Also, what are the annealing temperatures? If they are the same, one doesn't expect an appreciable hardness difference only due to difference in cooling method (I'm assuming you're working with a fully austenitic stainless steel; this may vary for other classes of SS).
Thanks for the information. How much is the difference in hardness? Also, if you specify the load used we can guess whether this is a surface effect (as suggested by Mikhail) or a bulk effect.
Once you check the microstructure, you can also extract information about grain size variations, precipitation etc.
We use EDS embedded in JEOL-6000 SEM for this purposes. It is highly likely that metal has gas conatmination if you did not use vacuum chamber or inert gas flows
Dear Saad the annealed specimens should hsve the lower values of hardness
- Badges
- Science topic
- Similar topics
- Engineering
- Materials Engineering
- Annealing