Please help me understand this section clearly :
Under section 2.4.1 for manufacturing 410SS or CA15, the heat treatment called out is a double temper after austenitizing. However for the same alloy after welding under section 2.4.3 the standard indicates a single temper only.
ALso, the...
The weldment is going to require PWHT to get the hardess lower. Slowing down the cooling rate after welding will only do so much which is what you found out from your 5 coupons. Refer to the tempering temperature for 4130 and temper the weldment at the minimum required temperature. The PWHT...
I am assuming this a furnace fixture handling parts being heat treated? 500C is would be a low temperature tempering furnace. What is the current material being used in the service. Are you trying to replace the existing material or is this a new design?
As a general note - ASTM A297 HK in the...
The basic features of a MTR is what is relevant to you. If you have a certain specification you are looking for, make sure the MTR mentions the standard. If you are looking for additional testing such as tensile / hardness / impact properties - check to see if these tests have been completed...
UPDATE:
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...
Thank you, arunmrao.. What tempering temperatures would you suggest ?
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There is always some thing better out there...
Mahadhatu
No Sir.. I have not checked the grain size after heat treatment.
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...
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...
Ed,
This problem is evident in CA6NM castings with thinner walls (0.5") and not in thick wall castings. If the same configuration is cast out of something like 316SS we don't have this issue.
If moisture was the main cause, all of out castings should have the same problem which is not the...
Melted using air melt induction furnaces. We either use fresh materials (100% Chrome, Ni, 100% Mo and Low carbon steel) or ingots purchased from as master melter. According to the Certs from the Master melter, the average Nitrogen in the ingots is 0.02%. We do not have the capability of...
thread330-217250
The above thread references Nitrogen solubility in CA6NM. We are having porosity issues in casting with thinner walls (0.5"). I am having our heat tested for nitrogen content. In the mean time can any one comment about what percentage of Nitrogen would cause porosity in CA6Nm...
Thanks for all your comments.
The alloys I am most concerned with are stainless steels such as CA6NM, 304, 316, CD4MCu etc and their respective L grades. That is the reason why we switched to Pure manganese.
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There is always some thing better out...
Ed,
You make an excellent point!
Its funny how we overlook the obvious and focus on complicated scenarios when problem solving.
I will post my findings.
I appreciate your input.
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There is always some thing better out there...
Mahadhatu
Thanks for your comments. I am more interested in the performance aspect of these alloys. Depending on the final desired carbon content of the alloy under consideration, we use either electrolytic manganese( almost no C) or standard ferro manganese. Alloys where we use the this low carbon...
Has any one done any studies or know references pointing to which form of manganese is more effective in de-oxidation of steel melts? (ferro Manganese or pure electrolytic manganese)
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There is always some thing better out there...
Mahadhatu
