1950, Rolls Royce inconel finishes?

[Serafino]

Hello all, first-time poster tips his hat to everyone.

I have a long shot question. I would be grateful for any help anyone can give.

I am looking for information on what sort of finish options were being used by Rolls in the early '50s for jet engine parts made of inconel. In particular for Derwent mk 9 balance pipes.

Thanks!

[flipflopman RB199]

Serafino,

As far as I am aware, and I'm sure somebody will correct me if I am wrong, Inconel came in a metallic gold/bronze type finish. Almost akin to cadmium coated nuts and bolts, with a matt finish.


Flipflopman

[Serafino]

Hi thanks for the reply Flipflopman.

Any idea how the coating was applied or what it was made of? I have no idea what technologies they had back then for this sort of thing.

The examples I've seen show three different finishes: a machine finish, a sort of bead-blasted satin look as on the examples on the right here, and a very matte almost velvety look as on the left. Although they have a hint of bronze color here in person they just look a warm grey.

http://img234.imageshack.us/img234/9787/bpcompzu2.jpg

[On_The_Top_Bunk]

http://www.pprune.org/forums/forumdisplay.php?f=22

Try posting on the engineers forum. You may get a better response.

[movadinkampa747]

Now where have I seen those ring pieces before???????? I know





http://registry.rebelscum.com/reviews/obiwan_anh_images/Obi_ANH_WPlaque.jpg

I didnt really know that. Its just everytime I typed in Derwent mk 9 balance pipes on google it came up with obeys lightsaber. I think you need the Star wars forum Serafino.

May the force be with you................:hmm:

[Serafino]

Mofadinkampa--Thanks for the tip, but they don't know any more than I do, believe me. ;)

On_The_Top_Bunk--thanks, will do!

[flipflopman RB199]

Serafino,

Again, as far as I am aware, and am open to correction, Inconel is actually the alloy itself, and the finish is actually a natural metal finish of the alloy, so I would imagine the differences you describe would actually be differences between how the individual parts were finished in a manufacturing sense. Some may have been milled, others shot blasted, others with a cast finish etc..


Hope this helps


Flipflopman

[modtinbasher]

In my pre-life, I used to hand work various exotic nickel/chrome alloys as they were then, such as the nimonic alloys, jetheat, and inconel to make all sorts of bits, de-icing pipes being one and bits for gas turbines another. Most of these metals were difficult to manipulate inconel being an absolute BA$£ARD to form and shape and as I remember it had a distinct "springiness" so you had to overform it to produce the particular profile required. As to its colour, the pictures already displayed look just about right to me, I don't remember any plating of any type, I don't think it was done in those days.

As an aside, cadmium is an absolute 'no-no' these days, despite many old drawings calling for items to be cad-plated and passivated.' Mind you, I believe it is still carried out, because if the drawing says so, you do it! If a military aircraft part is needed, it's easier and less time consuming to make what's specified than starting to apply for deviations. I've been away from manufacturing for some time now so I can't plead to be up to date, but, I'm still very interested!

So, after working, and then any assembly, the various bits were welded using TIG or 'argon-arc' as it was more easily known in those days, and this would be done by hand using a technique called 'argon backing'.

This involved purging the rear of the weld with argon during the welding process. The finished manual weld looked just the same on the reverse of the weld as on the face side as no oxidation of the weld metal or the surrounding area had been allowed.
The completed item was then tested for cracks using a dye penetrant process such as 'Ardrox' (X-ray being a bit 'with the fairies' in those days), and then the eventual finish was produced by powder blasting (similar to sand blasting), but I can't remember what the media was that was used. Oh, happy memories.

I hope that answers your query. If you want to know how to make a jet pipe by hand, (the tinny bit, not the bit made by machines) give me a shout and I'll let you know how we did it.

[Serafino]

Flipflopman--thanks again. Yes inconel is the metal itself. What got me started on this question is a source I had at a museum who was researching the question and believed that different 'finishes' were called out in different versions of the same part with different part numbers, and that some of these were finishes were "metal coatings". Unfortunately he no longer works there and so our information has dried up.

Since I've never seen such a powdery-looking matte surface result from bead-blasting, I'm searching for information on what the process might have been.

Modtinbasher--thank you for all that info.! I'm always amazed by the specialized techniques that are developed in industry to solve specific problems.

I am especially intrigued by your reference to 'powder blasting'--if that involved the use of different media than the beads or sand in use currently, it might help explain the super-matte finish that intrigues me in the left-hand sample above.

[movadinkampa747]

Any chance you could keep this to the Engineers thread as nobody really cares about light saber spares....................

http://www.pprune.org/forums/showthread.php?t=241925

[flipflopman RB199]

movadinkampa747,

The day you make an intelligent and reasoned comment on a thread in this forum that is not deliberately intended to flame, or evoke a reaction from someone, will be the day you are qualified to decide what belongs where.

Till then mate, wind your neck in eh? :ok:


Flipflopman

[MReyn24050]

Inconel® refers to a family of trademarked high strength austenitic nickel-chromium-iron alloys that have exceptional anti-corrosion and heat-resistance properties. These alloys contain high levels of nickel and can be thought of as super-stainless steels. Inconel alloys are used for a variety of extreme applications including navy boat exhaust ducts, submarine propulsion motors, undersea cable sheathing, heat exchanger tubing and gas turbine shroud rings.

[movadinkampa747]

Fascinating......................... I bet those evenings just fly by in your house http://ruinsmiley.tripod.com/MyStarWarssmileys_files/LSVADER.gif

[Crash alot]

movadinkampa747,

Ii may not of posted much, this being only my second. and may not have been around as long as you. But in all honesty after reading this forum for quite a while, i think am safe in asking, please shut the F£$K up and go to the disney site where am sure your mental age would be appriciated



sorry folks, waste of a post but it had to be said

[modtinbasher]

Flipflopman--thanks again. Yes inconel is the metal itself. What got me started on this question is a source I had at a museum who was researching the question and believed that different 'finishes' were called out in different versions of the same part with different part numbers, and that some of these were finishes were "metal coatings". Unfortunately he no longer works there and so our information has dried up.

Since I've never seen such a powdery-looking matte surface result from bead-blasting, I'm searching for information on what the process might have been.

Modtinbasher--thank you for all that info.! I'm always amazed by the specialized techniques that are developed in industry to solve specific problems.

I am especially intrigued by your reference to 'powder blasting'--if that involved the use of different media than the beads or sand in use currently, it might help explain the super-matte finish that intrigues me in the left-hand sample above.


Serafino - The powder used in the very fine matt finish was a glass based product as I remember, the consistency was somewhere between talc and sand. I distinctly remember grabbing a handful of it and was amazed at the smoothness. That was, I reckon, in 1963. Much water has flowed since, as they say....

[modtinbasher]

Serafino- just searched google for 'powder blasting', quite a few hits. One quoted alumina (aluminium oxide) as an abraiding media. That would sound about right with what we know about abrasives these days. I don't remember aluminium oxide being bandied about much in the 50s/60s though.....

[Serafino]

Thanks again--I will look into very fine glass blasting media and the resulting finishes.

[hobie]

A word of caution ...... some time ago I purchased an old Rolls Conway to display in our canteen, to celibrate a long relationship with the Aviation world ...... much of the external hardware was taken off and either painted .... blasted ....... or polished, where appropriate, before re-assembly ....

To keep the story short one particular item reacted to the blasting process /media (as far as we know) and blew the blasting machine into another world !!!! :eek: the sub contractor involved was convinced it was a reaction between the blasting media and an exotic metal alloy :confused:

http://i7.tinypic.com/281c8jk.jpg

[Serafino]

Yikes, that's intriguingly bizarre. I wonder what the medium was?

[hobie]

Yikes, that's intriguingly bizarre. I wonder what the medium was?

I'm retired since 92 so I'm a little out of the circuit these days but some of the more conventional media's are noted below .... they do seem fairly innocent to me but certainly something created a very big bang :confused: .......

Aluminium Oxide
Corn Cob
Crushed Glass
Glass Beads
Plastic
Pumice
Silicon carbide
Steel Grit
Steel Shot
Walnut Shell