Hello members,


1. How to calculate the impact test requirement for the material when its thickness exceeds 100 mm.

Construction: Welded construction.


2. As per UCS-66, if computed MDMT is greater than the required MDMDT, the material has to be impact tested or some other low temperature service material has to be selected.. Right.

My question is after the impact testing is done, how can we find the MDMT is greater/lesser than the required MDMT??.


Appreciate your reply.


Thanks,
Siva..

Hello sivastic

UG-84 of the code gives all the details. Basically you reduce the temperature of the charpy specimen to the minimum temperature at which you want to set the vessel, and get the required energy for the impact test. If you need the absolute lowest MDMT, you would have to do a number of such tests, lowering the temperature each time until the energy requirement area no longer met the requirements.

Thank you Mr. Ray for let me knowing the clear idea about that.

Also give me the suggestion that How to calculate the impact test requirement for the material when its thickness exceeds 100 mm.

Construction: Welded construction.


Thanks in advance.

Hello sivastic

Any material irrespective of its thickness can be impact tested. This is not really the issue. You need to get the impact specimen down to the MDTM of the vessel or tank, impact test it, and get the required amount of energy. If you wanted to know the lowest temperature to set the MDMT, you would have to test a number of sets of specimens and keep lowering the temperature until they just failed. This is a rather expensive set of tests.