Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
(OP)
Dear team,
As we know use of CS wire brush over SS and inconel welds are not preferable as it will lead to contamination and rust spots generation. Similarly what will the impact of using ss wire brush over Inconel welds ?
Weld :- Inconel 625
Regards,
Ratheesh N
As we know use of CS wire brush over SS and inconel welds are not preferable as it will lead to contamination and rust spots generation. Similarly what will the impact of using ss wire brush over Inconel welds ?
Weld :- Inconel 625
Regards,
Ratheesh N
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
DHURJATI SEN
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Our suppliers just mention stainless steel brushes, and look at you if you're from the moon when you ask what kind of stainless they are.
Even with "elevated" C%, or if they were a martensitic stainless steel (as this is cheaper), would it really matter?
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Would it harm the underlying material? Probably not, if you believe that wire brushing some how helps then you are not trying very hard. When you brush you also embed bits of the oxide scale and Cr depleted metal.
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P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Concern is not the type of stainless steel wire brush used. Concern here is what is the impact if we use SS wire brush on Inconel as iron content is more in the ss compare to Inconel.
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Thanks.. i would like to add the back ground for this case which will have more clarity on my query.
We have fabricated Inconel spools from our shop and shipped to field with proper preservations. During the site fabrications ,we found rust spots in root side of the weld in parent metal as well as welds (with borescope inspection) .. we have cleaned it(pickling) several time and it was very difficult to remove..
Client claimed we may have used CS wire brushes for clean the welds. But we have dedicated shops for SS and Inconel and there is no chance to use CS wire brush over Inconel. So we were analyzing how the rust spots came. we have used SS wire brushes for cleaning the welds..
query is
1) whether the overcleaning and depletion of chromium layer lead to the generation rust spots (we are regularly doing the Inconel spool works and this is first time we face this issue) ?
2) whether the usage of SS wire brushes having any role in this ?
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Or, remember that small flakes of metal will corrode easily, even of 625. If you have smeared and embedded metal then that could be the cause.
They are accusing you of using CS brushes, ask them what their inspector saw at your shop. No impector, then they don't care that much.
We used abrasive flap wheels because they would cut metal and were less likely to embed stuff. And then pickled after falp wheel.
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P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Or, remember that small flakes of metal will corrode easily, even of 625. If you have smeared and embedded metal then that could be the cause.
They are accusing you of using CS brushes, ask them what their inspector saw at your shop. No impector, then they don't care that much.
We used abrasive flap wheels because they would cut metal and were less likely to embed stuff. And then pickled after falp wheel.
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P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
While mechanical cleaning like brush is physically to remove impurities (such as weld spatter), acid cleaning is chemically to dissolve contamination including rust.
Hence, check the acid cleaning procedure and whether properly followed at the site.
SiHyoung Lee
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
A simple passivation (cleaning) of nitric acid or mixtures of citric and phosphoric acids will only remove embedded Fe. These will not remove rust, heat tint, scale, or the Cr depleted layer of metal under the oxides.
A pickling using a mixture of Nitric acid and HF will remove all of those things.
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P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Is the "simple passivation" common? I have never heard the actual case that there is kind of cleaning without removing rust but only for the limited usage.
I appreciate if you share the case when only the "embedded" Fe is to be removed.
SiHyoung Lee
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Straight 30-45% nitric is often used for this since it is fast (we required 15 min just because we needed a time) and works at room temp.
The citric or citric phosphoric blends work but require heating and take time (an hour at least, depending on temp).
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P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Some clients specifies to do pickling as per ASTM A 380. But ASTM A 380,its applicable for stainless steel. So its not mandatorily doing by all manufacturers, but following as a recommended one. Client also recommended to follow this whenever the surface contaminations found
any other standards or references for pickling of Inconel items and welds.. and how to select the pickling method from ASTM A 380 based on this Inconel metallurgy
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
I believe your case is exactly same as the one described in ASM Metal handbook Volume 5.(Surface Engineering of Nickel and Nickel Alloys )
(Quoted from ASM Metal handbook Vol 5 Surface Engineering of Nickel and Nickel Alloys )
Detection and Removal of Embedded Iron.
During mechanical operations such as rolling to shape or hot pressing, small particles of iron may become so firmly embedded in the surfaces of nickel alloys that they cannot be removed by the cleaning methods normally used for dissolving grease or cutting compounds. Under certain corrosive conditions, such iron particles can initiate local attack.
(Omitted)
A solution of hydrochloric acid and ferric chloride, Formula 12, is used to remove embedded iron. This solution should be used cold and should remain in contact with the metal for only the minimum time required for iron removal, not exceeding 1 h. After the work is removed from the solution, it should be rinsed thoroughly in cold water, then rinsed again in warm water. The detection tests should be repeated to verify the removal of the iron.
Formula 12
HCL 1.16 Sp gr - 1 wt%, 30 ml, ambient temperature
FeCl3 - 1 wt % - 11g, ambient temperature
Water - 1000 ml, ambient temperature
P.S. Next time, do not use steel brush but si carbide or al oxide.
SiHyoung Lee
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
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P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Regarding the formula 12, refer to the below link. You can check it whether true or not. ("Detection and Removal of Embedded Iron.")
https://dl.asminternational.org/handbooks/book/20/...
Meanwhile, regarding the use of nitric acid, it is listed in formula no. 1 as a "pickling method". However, it is not shown in the section of removal of "embedded iron" by the steel brush, which is applicable for the case.
In addition, referring to section of "brushing", you find the below statement.
"They should not be made of steel or brass wire, because small particles from the brush are always "embedded" in the metal during the process. Steel particles rust, and brass particles discolor the nickel alloys."
I hope the above are all clear.
Thank you.
SiHyoung Lee
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Detection of free Fe on a surface is tricky.
The best test is not one that people really want to use as it involves HgCN as a reagent.
We would sprat a surface with DI and cover with an absorbent pad to keep it wet.
Give it overnight and look for rust spots.
Or buy some white Head & Shoulders shampoo (It must be the white variety).
Brush it on and then mist with DI to keep it damp.
If blue spots appear you have Fe.
Some H&S is blue because it is made in a plant that still has some steel piping. They dye it a standard color so that each batch looks the same.
The white is made in a plant that is all SS piping.
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P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
https://theberkey.com/blogs/water-filter/understan....
Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Is there any available reference that nitric acid can work for the case contaminated by embedded iron in "Nickel alloy"(Not stainless steel)? (Any published book??)
(Please note that I am not attacking you but hope to confirm it by reference and find any other useful information. Actually, there are a number of references that nitric acid can dissolve Fe in "SS", but, at my end, no available reference for the specific case of the firmly embedded Fe in "Nickel alloy", except for the one in ASM.)
SiHyoung Lee
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Most of hte scientific work on this is either under the ASME BPE or EHEDG, both dealing with hygienic service (esp pahrma).
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P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
"Everyone is entitled to their own opinions, but they are not entitled to their own facts."
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
One of our vendor has claimed that usage of zirconia grinder is recommended over Inconel material as it will not result in the change in surface chemical composition. Would like to get your view on this
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
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P.E. Metallurgy, consulting work welcomed
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Any specific public reference or failure report you have related to the local galvanic effect by Silicon carbide? (The reason why I am asking is due to that sometimes I review vendor documents and possibly find the use in future and need to recommend another one explaining the reason.) I appreciate if it has some link or you share the name of the title.
Thanks in advance.
SiHyoung Lee
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?
-Dik
RE: Impact of using SS wire brush over the Inconel welds - any chances of rust spots generation ?
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed