I have found out that in some research journals, people have reported solution heat treatment of 17-4 PH stainless steel at 1040 C for 30 min and quenching in air ( Air cooling) whether some of them reported heating at 1040 for 1 hr than water quenched. Kindly answer me which process to be adopted to perform solution heat treatment in case of 17-4 PH stainless steel ?? Do I really have to go for 1hr of solution heat treatment or 30 min will be enough along with which type of quenching is required ( water or Air quenching) ??
Dear RISHABH SAXENA, there is no answer which is totally matching to this question. The answer is: it depends…. First, the timeframe for the solution annealing is the heat penetration time (the time needed to have core of your product at annealing temperature) + holding time. You do this process to transfer your material to an austenitic structure. For this you should check the sample sizes in the journals if these are similar to your own. For the quenching, your cooling rate is important. You should check your journals for time temperature transformation diagrams. You should find the effect of your cooling rate on the material structure especially the martensite content in your case. You have to meet the critical cooling rate. That’s necessary to avoid diffusion based phase transformations (this means that there is no formation of bainite and perlite). You can use a quenching medium (water, air, oil …) to meet your cooling rate. We hope this could help you. Best Regards, Torsten
No, the material will be kept for a calculated time at the annealing temperature and then will undergo a cool down profile. There is no need for rapid cool down as the annealing is done under a hydrogen atmosphere, hence there will be no excessive scaling or corrosion on the surface. Furthermore we consider only low carbon material and due to that there is no risk for the formation of chromium carbides. Hope that helps. Best regards, Torsten
Hi We had performed Cold bending operation for SA213TP347H tube. We need to perform PBHT of bend area of tube as per ASME sec-1 PG-19. We can know heat rate,soaking temperature, soaking time from Code but Code doesn't specify cooling rate. Can we perform forced air cooli g method instead of water quenching? what should be cooling rate?
Dear mrahul28, sorry for the late reply. We have checked internally if we can answer your question. Unfortunately, we cannot provide a clear answer. However, you are welcome to contact us or our representatives by e-mail or phone: www.dockweiler.com/en/contact
Dear Jivesh, to extend the dedicated duration time for a given alloy at a specific temperature would not change the result of annealing. Once an equilibrium of alloy-crystallization is achieved a longer duration time will not change it. Best Regards, Torsten
repeated solution annealing is of no particular use. Once you did a proper annealing and the austenitic structure is well defined repeated annealing would neither harmful nor beneficial.
I have found out that in some research journals, people have reported solution heat treatment of 17-4 PH stainless steel at 1040 C for 30 min and quenching in air ( Air cooling) whether some of them reported heating at 1040 for 1 hr than water quenched. Kindly answer me which process to be adopted to perform solution heat treatment in case of 17-4 PH stainless steel ??
Do I really have to go for 1hr of solution heat treatment or 30 min will be enough along with which type of quenching is required ( water or Air quenching) ??
Dear RISHABH SAXENA, there is no answer which is totally matching to this question. The answer is: it depends….
First, the timeframe for the solution annealing is the heat penetration time (the time needed to have core of your product at annealing temperature) + holding time. You do this process to transfer your material to an austenitic structure. For this you should check the sample sizes in the journals if these are similar to your own.
For the quenching, your cooling rate is important. You should check your journals for time temperature transformation diagrams. You should find the effect of your cooling rate on the material structure especially the martensite content in your case.
You have to meet the critical cooling rate. That’s necessary to avoid diffusion based phase transformations (this means that there is no formation of bainite and perlite).
You can use a quenching medium (water, air, oil …) to meet your cooling rate.
We hope this could help you.
Best Regards, Torsten
Is it not also important to Quench and stabilize the 316L after letting the Chroom re-diffuse at around 1050-1100 DegreesC ?
No, the material will be kept for a calculated time at the annealing temperature and then will undergo a cool down profile.
There is no need for rapid cool down as the annealing is done under a hydrogen atmosphere, hence there will be no excessive scaling or corrosion on the surface. Furthermore we consider only low carbon material and due to that there is no risk for the formation of chromium carbides.
Hope that helps.
Best regards,
Torsten
Hi
We had performed Cold bending operation for SA213TP347H tube. We need to perform PBHT of bend area of tube as per ASME sec-1 PG-19. We can know heat rate,soaking temperature, soaking time from Code but Code doesn't specify cooling rate. Can we perform forced air cooli g method instead of water quenching? what should be cooling rate?
Dear mrahul28,
sorry for the late reply. We have checked internally if we can answer your question.
Unfortunately, we cannot provide a clear answer. However, you are welcome to contact us or our representatives by e-mail or phone: www.dockweiler.com/en/contact
@@DockweilerAG Thank you very much for your reply. We will contact you.
What would be effect on stainless steel due to more soaking time?
Dear Jivesh,
to extend the dedicated duration time for a given alloy at a specific temperature would not change the result of annealing.
Once an equilibrium of alloy-crystallization is achieved a longer duration time will not change it.
Best Regards,
Torsten
@@DockweilerAG Thank you,but i have seen increase in grain size & decrease in hardness due to prolonged soaking.
What would be the effect on repeat solution annealing on 316 Stainless steel material?
Hi,
repeated solution annealing is of no particular use. Once you did a proper annealing and the austenitic structure is well defined repeated annealing would neither harmful nor beneficial.
I hope that answers your question.
Cheers Torsten
It was excellent explanation
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