Loading of Barrel when spraying Inconel 625

[Bob Weber]

Hi Members

I am doing lot of Inconel 625 spraying with JP-5000 gun. I found loading of barrel at the exiting end of the barrel. I tried to modify the exit end making it divergent. Though the problem could minimize yet the deposition is always noticed. May be I am missing some parameters.

Regards
Bob

[Manish Choudhary]

Hi Members

I am doing lot of Inconel 625 spraying with JP-5000 gun. I found loading of barrel at the exiting end of the barrel. I tried to modify the exit end making it divergent. Though the problem could minimize yet the deposition is always noticed. May be I am missing some parameters.

Regards
Bob

Hi Bob,

we MEC can provide you a hard coated barrel which will eliminate the barrel coating. Please write to marketing@mecpl.com with complete pictures of the barrel loading, we will give you the solution.

Thanks & Regards
Manish Choudhary
Metallizing Equipment Co. Pvt. Ltd, India
www.mecpl.com

[Bob Weber]

Hi Members

I am doing lot of Inconel 625 spraying with JP-5000 gun. I found loading of barrel at the exiting end of the barrel. I tried to modify the exit end making it divergent. Though the problem could minimize yet the deposition is always noticed. May be I am missing some parameters.

Regards
Bob

Hi Bob,

we MEC can provide you a hard coated barrel which will eliminate the barrel coating. Please write to marketing@mecpl.com with complete pictures of the barrel loading, we will give you the solution.

Thanks & Regards
Manish Choudhary
Metallizing Equipment Co. Pvt. Ltd, India
www.mecpl.com

Manish can you tell me the kind of coating done in the barrel??

[loriolo]

Hi Bob
I did a lot of big paper industry rolls, coated with 625 powder, I changed powder OEM, but the problem was the same, I obtained a little best result, blowing the powder in front to the exhaust system, from a can to another, doing this I could spray continuously for 24 minutes without barrel loading, the problem are the fines in powder, I tried with GP5000, DJ2600, DJ2700,but ever the barrel was loaded, at present my customer changed to Inconel 625 HVOFW wire system, and there is not more big porosity, process and material cost is lower, and quality is acceptable,before they must rework one roll every 3, loosing 8 working hours and 46 kg of powder.

[Bob Weber]

Hi Bob
I did a lot of big paper industry rolls, coated with 625 powder, I changed powder OEM, but the problem was the same, I obtained a little best result, blowing the powder in front to the exhaust system, from a can to another, doing this I could spray continuously for 24 minutes without barrel loading, the problem are the fines in powder, I tried with GP5000, DJ2600, DJ2700,but ever the barrel was loaded, at present my customer changed to Inconel 625 HVOFW wire system, and there is not more big porosity, process and material cost is lower, and quality is acceptable,before they must rework one roll every 3, loosing 8 working hours and 46 kg of powder.

Hi Luigi,

What is HVOFW wire system. is this similar to JP-5000 or DJ. Where can I get more info on this.

[djewell]

I agree with Luigi - fines in the powder are causing your problem. I suggest you look at an HVAF system. HVAF guns operate at a lower temperature than a JP5000, and they are axially fed, so the powder tends to stay in the center of the flame. Build up can occur, but it is much slower than what you are experiencing, and there are ways to prevent the build up.

[Bob Weber]

I agree with Luigi - fines in the powder are causing your problem. I suggest you look at an HVAF system. HVAF guns operate at a lower temperature than a JP5000, and they are axially fed, so the powder tends to stay in the center of the flame. Build up can occur, but it is much slower than what you are experiencing, and there are ways to prevent the build up.

Hi Dear,

I invested a lot in HVOF system and buying another system is not possible at this stage however if something can be change in gun parameter or gun parts to save on spares consumption.

[Joris Kraak]

Hi Bob,

We were facing similar problems when starting with inconel625 and the experience with this material and JP5000 torch learned that it is not easy to control. That does not mean it is not possible but everything must be in line and close to perfection or otherwise you will face problems!

I can recommend the following:

1. First of all check the cooling water and make sure the water is clean, use an e-pure to ensure low conductivity. Obviously many people would argue this suggestion but a fact is there will be an insulating layer formed on your barrel increasing the temperature inside the barrel. Furthermore check the water flow and the temperature in and out, this also has an effect on the barrel loading. You can always lower the temperature of the water a little to increase cooling capacity.

2. Check your injectors and make sure you use a good set of powder injectors, check the flow on stability. Any unstable flow can cause a disturbed injection causing particle bounding in the barrel resulting in loading.

3. Check the powder specifications so you know the amount of fines in the powder. As mentioned before this is a big contributor to the barrel loading. The smaller the difference between large and small particles the easier to optimize the whole process. You can experiment with different supplier and grain sizes. Even fine grain sizes are possible as long as the difference between smallest and biggest particle is small.

4. Reduce your feed rate to about 60gr/min (divergence of the powder is less), of course it will take longer but you can at least spray longer and have a high quality coating.

5. Check carrier gas and adjust it (first one side than the other side), What I normally do is lay on my back under the gun and check the injection. This is one of the most important in reducing the loading, please don't follow the standard sheets, it all depends on your system, your injectors, your spare parts supplier!

6. Even the quality of the copper use can have an effect on the barrel loading. I have tried 4 different suppliers and all differences, not too big but it has an effect on quality and loading. A hard faced barrel suggested by Manish is indeed an option.

7. Use a 4"barrel to start your optimization and get your process running! At our facility we are using 6" barrel to spray the Inconel 625, there is a difference between 4"and 6" in terms of porosity and DE but not significant. With a 4"barrel you should be able to spray a perfect coating as well!

Attached a pictures of HVOF sprayed Inconel 625 (JP5000) sprayed with a 4"barrel onto a shaft. Parameters: 850NLPM Oxygen 23LPH Kerosene, distance 325mm, traverse 5mm per rpm, injection 100gr/min. The topcoat is a Chromium carbide-Ni/Cr (75/25), samples were prepared in our laboratory and etched. Yes there is a little scratch for all the perfectionists but the good thing is that it was the last scratch

I hope this information helps and if you need any further info just let me know.

Kind regards,

Joris

[Parat Tech]

Hi Members

I am doing lot of Inconel 625 spraying with JP-5000 gun. I found loading of barrel at the exiting end of the barrel. I tried to modify the exit end making it divergent. Though the problem could minimize yet the deposition is always noticed. May be I am missing some parameters.

Regards
Bob

Bob, I have reference of similar problem faced by one of my customer & as per my knowledge he resolved the issue by decreasing powder velocity, using fine powder & increasing the O2 flow little higher so as to get better combustion.


Thanks

Harish Dhanadiya
https://www.parattech.com

[Stephen Booth]

Joris,

Have you ever experienced that the loading caused by suction from the JP 5000 to the feeder, even though the feeder is in the OFF position. Problem solved by pinch valve on feeder.

Just a thought, somehow contributes to the loading of the torch,

Merry Christmas and Happy New Year.

Hi Bob,

We were facing similar problems when starting with inconel625 and the experience with this material and JP5000 torch learned that it is not easy to control. That does not mean it is not possible but everything must be in line and close to perfection or otherwise you will face problems!

I can recommend the following:

1. First of all check the cooling water and make sure the water is clean, use an e-pure to ensure low conductivity. Obviously many people would argue this suggestion but a fact is there will be an insulating layer formed on your barrel increasing the temperature inside the barrel. Furthermore check the water flow and the temperature in and out, this also has an effect on the barrel loading. You can always lower the temperature of the water a little to increase cooling capacity.

2. Check your injectors and make sure you use a good set of powder injectors, check the flow on stability. Any unstable flow can cause a disturbed injection causing particle bounding in the barrel resulting in loading.

3. Check the powder specifications so you know the amount of fines in the powder. As mentioned before this is a big contributor to the barrel loading. The smaller the difference between large and small particles the easier to optimize the whole process. You can experiment with different supplier and grain sizes. Even fine grain sizes are possible as long as the difference between smallest and biggest particle is small.

4. Reduce your feed rate to about 60gr/min (divergence of the powder is less), of course it will take longer but you can at least spray longer and have a high quality coating.

5. Check carrier gas and adjust it (first one side than the other side), What I normally do is lay on my back under the gun and check the injection. This is one of the most important in reducing the loading, please don't follow the standard sheets, it all depends on your system, your injectors, your spare parts supplier!

6. Even the quality of the copper use can have an effect on the barrel loading. I have tried 4 different suppliers and all differences, not too big but it has an effect on quality and loading. A hard faced barrel suggested by Manish is indeed an option.

7. Use a 4"barrel to start your optimization and get your process running! At our facility we are using 6" barrel to spray the Inconel 625, there is a difference between 4"and 6" in terms of porosity and DE but not significant. With a 4"barrel you should be able to spray a perfect coating as well!

Attached a pictures of HVOF sprayed Inconel 625 (JP5000) sprayed with a 4"barrel onto a shaft. Parameters: 850NLPM Oxygen 23LPH Kerosene, distance 325mm, traverse 5mm per rpm, injection 100gr/min. The topcoat is a Chromium carbide-Ni/Cr (75/25), samples were prepared in our laboratory and etched. Yes there is a little scratch for all the perfectionists but the good thing is that it was the last scratch

I hope this information helps and if you need any further info just let me know.

Kind regards,

Joris

[Joris Kraak]

Hi Stephen,

You are absolutely right, just put your finger on the powder injector if the JP5000 runs full flow, you can feel the suction power!

cheers,
Joris

Joris,

Have you ever experienced that the loading caused by suction from the JP 5000 to the feeder, even though the feeder is in the OFF position. Problem solved by pinch valve on feeder.

Just a thought, somehow contributes to the loading of the torch,

Merry Christmas and Happy New Year.

Hi Bob,

We were facing similar problems when starting with inconel625 and the experience with this material and JP5000 torch learned that it is not easy to control. That does not mean it is not possible but everything must be in line and close to perfection or otherwise you will face problems!

I can recommend the following:

1. First of all check the cooling water and make sure the water is clean, use an e-pure to ensure low conductivity. Obviously many people would argue this suggestion but a fact is there will be an insulating layer formed on your barrel increasing the temperature inside the barrel. Furthermore check the water flow and the temperature in and out, this also has an effect on the barrel loading. You can always lower the temperature of the water a little to increase cooling capacity.

2. Check your injectors and make sure you use a good set of powder injectors, check the flow on stability. Any unstable flow can cause a disturbed injection causing particle bounding in the barrel resulting in loading.

3. Check the powder specifications so you know the amount of fines in the powder. As mentioned before this is a big contributor to the barrel loading. The smaller the difference between large and small particles the easier to optimize the whole process. You can experiment with different supplier and grain sizes. Even fine grain sizes are possible as long as the difference between smallest and biggest particle is small.

4. Reduce your feed rate to about 60gr/min (divergence of the powder is less), of course it will take longer but you can at least spray longer and have a high quality coating.

5. Check carrier gas and adjust it (first one side than the other side), What I normally do is lay on my back under the gun and check the injection. This is one of the most important in reducing the loading, please don't follow the standard sheets, it all depends on your system, your injectors, your spare parts supplier!

6. Even the quality of the copper use can have an effect on the barrel loading. I have tried 4 different suppliers and all differences, not too big but it has an effect on quality and loading. A hard faced barrel suggested by Manish is indeed an option.

7. Use a 4"barrel to start your optimization and get your process running! At our facility we are using 6" barrel to spray the Inconel 625, there is a difference between 4"and 6" in terms of porosity and DE but not significant. With a 4"barrel you should be able to spray a perfect coating as well!

Attached a pictures of HVOF sprayed Inconel 625 (JP5000) sprayed with a 4"barrel onto a shaft. Parameters: 850NLPM Oxygen 23LPH Kerosene, distance 325mm, traverse 5mm per rpm, injection 100gr/min. The topcoat is a Chromium carbide-Ni/Cr (75/25), samples were prepared in our laboratory and etched. Yes there is a little scratch for all the perfectionists but the good thing is that it was the last scratch

I hope this information helps and if you need any further info just let me know.

Kind regards,

Joris

[Bob Weber]

Hi Bob,

We were facing similar problems when starting with inconel625 and the experience with this material and JP5000 torch learned that it is not easy to control. That does not mean it is not possible but everything must be in line and close to perfection or otherwise you will face problems!

I can recommend the following:

1. First of all check the cooling water and make sure the water is clean, use an e-pure to ensure low conductivity. Obviously many people would argue this suggestion but a fact is there will be an insulating layer formed on your barrel increasing the temperature inside the barrel. Furthermore check the water flow and the temperature in and out, this also has an effect on the barrel loading. You can always lower the temperature of the water a little to increase cooling capacity.

2. Check your injectors and make sure you use a good set of powder injectors, check the flow on stability. Any unstable flow can cause a disturbed injection causing particle bounding in the barrel resulting in loading.

3. Check the powder specifications so you know the amount of fines in the powder. As mentioned before this is a big contributor to the barrel loading. The smaller the difference between large and small particles the easier to optimize the whole process. You can experiment with different supplier and grain sizes. Even fine grain sizes are possible as long as the difference between smallest and biggest particle is small.

4. Reduce your feed rate to about 60gr/min (divergence of the powder is less), of course it will take longer but you can at least spray longer and have a high quality coating.

5. Check carrier gas and adjust it (first one side than the other side), What I normally do is lay on my back under the gun and check the injection. This is one of the most important in reducing the loading, please don't follow the standard sheets, it all depends on your system, your injectors, your spare parts supplier!

6. Even the quality of the copper use can have an effect on the barrel loading. I have tried 4 different suppliers and all differences, not too big but it has an effect on quality and loading. A hard faced barrel suggested by Manish is indeed an option.

7. Use a 4"barrel to start your optimization and get your process running! At our facility we are using 6" barrel to spray the Inconel 625, there is a difference between 4"and 6" in terms of porosity and DE but not significant. With a 4"barrel you should be able to spray a perfect coating as well!

Attached a pictures of HVOF sprayed Inconel 625 (JP5000) sprayed with a 4"barrel onto a shaft. Parameters: 850NLPM Oxygen 23LPH Kerosene, distance 325mm, traverse 5mm per rpm, injection 100gr/min. The topcoat is a Chromium carbide-Ni/Cr (75/25), samples were prepared in our laboratory and etched. Yes there is a little scratch for all the perfectionists but the good thing is that it was the last scratch

I hope this information helps and if you need any further info just let me know.

Kind regards,

Joris

Hi Joris,

Looks like you have in depth knowledge for this coating and even for JP-5000. I really liked your suggestion and will implement with my system after holidays.

Regards
Bob

---

Hi Members

I am doing lot of Inconel 625 spraying with JP-5000 gun. I found loading of barrel at the exiting end of the barrel. I tried to modify the exit end making it divergent. Though the problem could minimize yet the deposition is always noticed. May be I am missing some parameters.

Regards
Bob

Bob, I have reference of similar problem faced by one of my customer & as per my knowledge he resolved the issue by decreasing powder velocity, using fine powder & increasing the O2 flow little higher so as to get better combustion.


Thanks

Harish Dhanadiya
https://www.parattech.com

Hi Hari,

Thank you for the suggestion but I think Joris's recommendation looks more effective. The operational parameters and hard barrels, I will try first and later on I will definitely try yours too as my ultimate aim is good coating with cost saving.

Regards
Bob