ASTM A352 Grade LCB Heat Treatment Recommendation
ASTM A352 Grade LCB Heat Treatment Recommendation
(OP)
What is the recommended heat treatment for ASTM A352 Grade LCB Steel to meet the impact testing requirements?
So far I have tried a few heat treatment cycles. Normalized at 1625F and tempered at 1125. Double Normalized at 1625F and tempered at 1125F, water quenched from 1625F and tempered at 1125F. The maximum value I got was 8 ft-lb in the Q and T condition which does not meet the minimum requirement.
Chemistry is
C 0.25, Si - 0.45, Mn - 0.96, S - 0.012, P - 0.018, Cr - 0.42
Any helpful tips would be greatly appreciated.
So far I have tried a few heat treatment cycles. Normalized at 1625F and tempered at 1125. Double Normalized at 1625F and tempered at 1125F, water quenched from 1625F and tempered at 1125F. The maximum value I got was 8 ft-lb in the Q and T condition which does not meet the minimum requirement.
Chemistry is
C 0.25, Si - 0.45, Mn - 0.96, S - 0.012, P - 0.018, Cr - 0.42
Any helpful tips would be greatly appreciated.
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There is always some thing better out there...
Mahadhatu





RE: ASTM A352 Grade LCB Heat Treatment Recommendation
RE: ASTM A352 Grade LCB Heat Treatment Recommendation
I am not sure whether my selection of Normalizing temperature is correct considering the presence of Chromium ( 0.42).
I also found that the impact property was the same regardless if the steel was tempered after Normalizing.
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There is always some thing better out there...
Mahadhatu
RE: ASTM A352 Grade LCB Heat Treatment Recommendation
RE: ASTM A352 Grade LCB Heat Treatment Recommendation
--------------------------------------
There is always some thing better out there...
Mahadhatu
RE: ASTM A352 Grade LCB Heat Treatment Recommendation
RE: ASTM A352 Grade LCB Heat Treatment Recommendation
Austenitize
Liquid Quench (this is in the material specification for ferritic materials for thicker castings) or normalize.
Temper at 1100 deg F minimum.
I would suspect your section thickness of the casting requires liquid quenching or faster cooling if normalizing.
RE: ASTM A352 Grade LCB Heat Treatment Recommendation
RE: ASTM A352 Grade LCB Heat Treatment Recommendation
RE: ASTM A352 Grade LCB Heat Treatment Recommendation
Thank you every one for your input and help.
Arunmrao: We did not have a choice to change chemistry on this part. I heat treated one of the test bars with your recommendation of a double temper and got a 3ft-lb value at minus 50 deg F.
Metengr: I did not get a value higher than 3ft-lbs with your recommended heat treatment cycles. The part in question has a maximum wall thickness of 3". I was performing tests on test bars from the same heat that I had cast for testing purposes. I tried liquid quench as well but with no improvement in the impact values.
Jwhit: Your recommendation of the higher temperature homogenize worked along with the normalize - quench and temper. I heat treated 3 test bars out of the same heat as follows and got the following results:
1750F - 2h - Air Cool; 1650F - 2h - Water quench - 1250F 6h Air Cool - 15ft-lb at minus 50 deg F
1750F - 2h - Air Cool; 1650F - 2h - Oil quench - 1250F 6h Air Cool - 12ft-lb at minus 50 deg F
1750F - 2h - Air Cool; 1650F - 2h - Air quench - 1250F 6h Air Cool - 8ft-lb at minus 50 deg F
I did not measure the grain size on any of these test bar samples but I believe our initial casting had large grain size leading to lower impact properties. The initial homogenize cycle helped reduce this grain size just enough to push the impact value over the minimum values with liquid quench but not with air quench.
I am assuming though that if I had the right chemistry and had used the correct grain refiners during casting we would be able to exceed the impact values with a normalize and temper heat treatment cycle only without any of the above extensive cycles.
Again, Thanks for all of your help.
--------------------------------------
There is always some thing better out there...
Mahadhatu
RE: ASTM A352 Grade LCB Heat Treatment Recommendation