Dear all,

how can we determine that a material can be found both in normalized and fine grain sized form. I am trying to check SA-106 B. I have refered to ASME SEC-II A but there nothing is wriiten about this particluar material with regard to normalization and fine grain practice.
if we go for SA-516 70, ASME SEC II A mentions normalization for this material.

In ASME SEC II A, for a number of materials we have some heat treatement procedures but I am not sure whether that comes under normalization catergory or not and similarly fine grain size practice.

I am trying to use curve C of UCS66 for some maeterials for which it is manadatory to have such materials both in normalized and fine grain sized.

Hello Farid

Fine grain can be confusing. The term refers to the size of the grain structure (crystal size) of the metal. If you can achieve a fine grain, the metal generally can generally operate at a lower temperature. For example, SA 516 60 has a small grain size than SA 515 60, and can consequently operate at a lower temperature. The practice of using normalising heat treatment re-grows smaller grains at the grain boundaries, thus perhaps doubling the number of grains per square inch.

If an SA 106 B pipe is normalised, you may be able to use for lower temperatures.

To my knowledge fine grain practice can be determined in two ways. The first would be to specify grain refining elements be added at the manufacturing stage. I do not know of the specifics but addition of aluminum is one way to force a smaller grain size. The second method is to perform a test which determines the grain size. This is done by packing in graphite and then measuring grain size.

I have heard of companies spending the money and impact testing SA-106 B in an attempt to use it at lower temperature and were not able to use much material.

Regards,
EJL