The metal still seems too thin to be a cylinder wall and the artifact does not have the ridges that are present on the cylinder walls.

Some others members made the hypothesis that it could a piece à the oiling system.

Leafing through my books, I found this image of an oil feeder adapted to the PL7 (the cylindrical item)

I know that this aircraft had a Hispano-Suiza very different from the Lorraine. This oil feeder was intended to allow the oil to be preheated an immediatly in  use for a quicker and safer throttle-up.

We know that it's likely that the PL8 version 1 had an oil preheating system. Could it be that Levasseur adopted the same system as for its contemporary PL7? Do you have any assembly diagrams? (I do not possess any).

Hi Ric,

What carbon measurement do you have (if any)?

For Silicon, I'm a bit surprised by levels above 3%...

The Vanadium and Molybdenum content is the sign of a steel of a certain quality (of a certain price) for the 1920s standard, especially in Europe. According to Jean Oertlé, low levels of Vanadium further enhance a part's core hardness without making it more brittle. That said, the grades are modest. It is used in certain bolts, for example.

With 3% silicon and around 0.50% manganese, this is a high-grade “manganese-silicon” industrial steel, approaching the “F” category of the “Houille Blanche” article. The only difference is the silicon content (generally speaking, at the time, over 2% was a brittleness factor), but vanadium, molybdenum and chromium can perhaps mitigate this effect. I'm not a metallurgist...

The use of chromium is not surprising, given its thermal resistance and its ability to homogenize a part during the quenching process. It also makes parts less brittle (more elastic) for the same hardness, but with a lower carbon content. 

The zinc content is also interesting. At the time, zinc was used in moving parts, such as bearings, for its anti-friction properties.

For all this, I'm basing myself on the Jean Oertlé manual I mentioned earlier.


So we certainly have a very special piece of steel. And quite expensive for its time. A sort of compromise between hardness, elasticity, strength, resistance to impact, heating and friction...

It would be interesting to know the carbon content. A medium-hard steel made in 1920 generally has a carbon content of between 0.40 and 0.45. For manufacturers, by using other elements, lowering this content while preserving hardness and resistance to deformation is interesting, as it makes the part less brittle and therefore less likely to break on impact. 

I think we need a metallurgist's opinion on the properties of a steel alloyed with all these elements. From these properties we might be able to deduce its use.

The clearest definition of "special steel" I've found is at https://www.voestalpine.com/blog/en/innovation-technology/what-is-special-steel/

"When Steel Becomes Special
As so often in life, when it comes to special steel it is the intrinsic values that count. Including those which are absent. What makes these steel grades special is their purity. That means an exceptionally low sulfur and phosphorus content: no more than 0.025%, or 25 parts in a thousand. That is comparable to two tiny pinches of salt in a liter of water, which is why extreme precision is required to achieve the chemical compositions of special steel grades. It is the same level of precision as demanded in their subsequent processing.
The exceptional properties of special steel, such as resistance to corrosion and heat, strength, wear resistance, workability, and polishability, all depend on its composition and the care with which it is produced. This is where special additives, so-called alloys, come into play. The manufacturers’ “recipe books” include a variety of ingredients:
•   Chrome: for resistance to corrosion and heat
•   Tungsten and cobalt: increase wear resistance which is important for milling tools and drills
•   Chrome and nickel: increase weld strength
•   Molybdenum: increases heat resistance and makes steel rust-proof
•   Titanium, niobium: creates resistance to intergranular corrosion
•   Manganese: increases tensile strength"

We have 15 XRF scans of various points on the exterior surface of our cylindrical artifact, 4 done in September 2021 and 11 done in November 2021. As expected, in all scans, iron (FE) was greater than 90%.
• The cobalt, titanium, and lead detected are almost certainly attributable to the bluish-gray paint and are not almost certainly part of the steel alloy.
• The most common probably-alloyed element (found in 12 of the 15 scans) was manganese. The percentage of manganese was quite consistent, from a low of 0.262% to a high of 0.580%.  The average was 0.458.
• The second most common probably-alloyed element was molybdenum (found in 7 of the 15 scans). The readings measured from a low of 0.015% to a high of 0.087% percentage, except for one reading of 0.683%. If we throw out the anomaly we get an average of 0.0325.
• In third place was chromium (found in 6 out 15 scans) from a high of 0.238% to a low of 0.096 for an average of 0.129.
• Silicon came in fourth (4 out of 15 scans) with readings of 3.507, 3.151, 3.010, and an anomalous 0.864.
• Zinc was found in 3 readings but the amounts are all over the shop: 2.425%, 1.303%, and 0.494%
• Vanadium was also present in 3 scans, more consistent: 0.118%, 0.059%, and 0.058%
• Inconsistent traces of copper and tin showed up in 2 scans and there was bit of phosphorus in 1 scan.  I think those can be dismissed as environmental contaminants.

The steel in this artifact fits the above definition of "special steel". The steels shown in the “Houille Blanche” article are quite different,  but neither does it fit the definition of 12L14 in  https://www.eatonsteel.com/12l14-cold-rolled-steel-bar.html
"12L14 is a standard resulfurized and rephosphorized carbon steel. Lead is also added in order to increase machinability, and it also means it can be bent, riveted, or crimped. However, this extra ductility and machinability do mean that 12L14 is slightly weaker than comparable carbon steel alloys."  There is no sulfur and no meaningful phosphorus in the artifact.  Also, there seems to be no such thing as 12L14 sheet. It's generally used for plating.

As you say, "special steel" seems to have been a catch-all name.  I think we have a piece of "special steel" and it should be possible to research its virtues, which may point us to where it came from.
 

Hello Ric, it's a pleasure to talk to you again.

It's a pleasure and privilege to have your help in conducting research in France. 

All in all, I'm quite relieved that you've clarified that the artifact in question may not be 12L14. Indeed, I didn't dare say it, but I felt that this alloy steel would have been a little too 'soft' to make good cylinders inner walls, especially of this size and with these constraints. It is indeed possible that this type of alloy would not have had the desired endurance.

The metal still seems too thin to be a cylinder wall and the artifact does not have the ridges that are present on the cylinder walls.

I think so (but I'm not a specialist. I like mechanics, but I'm more of a 'book man') that the hypothesis of medium-hard 'manganosilicium' alloy steel is an interesting trail to follow.

I'll pull the XRF data together and we'll see what that tells us.

From the XRF data you evoked, do you have the exact chemical composition of the artifact? (i.e. carbon, lead, manganese, silicon, phosphorus, other...) and the type of treatment it has undergone (quenching...). This could be useful for making comparisons with the different families of French special steels of the time.

The XRF data give us the percentages of elements detected but nothing about treatments.  Several points on the artifact are samples and the results vary somewhat.  Sometimes elements show up that are probably contaminates that adhered to the artifact during the time it was buried in the mud.  I'll be looking for elements that show up consistently in roughly th same percentages.

Yes, I've seen that the PL4 parts catalog often mentions special steels. It's not surprising, since this generic term in France is a bit of a 'catch-all' (not sure for the translation...) for a wide variety of steels alloyed with other components and with specific properties.

"Catch-all" is the right term. 

Hello Ric, it's a pleasure to talk to you again.

All in all, I'm quite relieved that you've clarified that the artifact in question may not be 12L14. Indeed, I didn't dare say it, but I felt that this alloy steel would have been a little too 'soft' to make good cylinders inner walls, especially of this size and with these constraints. It is indeed possible that this type of alloy would not have had the desired endurance.

I think so (but I'm not a specialist. I like mechanics, but I'm more of a 'book man') that the hypothesis of medium-hard 'manganosilicium' alloy steel is an interesting trail to follow.

From the XRF data you evoked, do you have the exact chemical composition of the artifact? (i.e. carbon, lead, manganese, silicon, phosphorus, other...) and the type of treatment it has undergone (quenching...). This could be useful for making comparisons with the different families of French special steels of the time.

Yes, I've seen that the PL4 parts catalog often mentions special steels. It's not surprising, since this generic term in France is a bit of a 'catch-all' (not sure for the translation...) for a wide variety of steels alloyed with other components and with specific properties.

I was lucky enough to come across this copy of the 12Eb mechanics' manual. I propose to copy it for you, page by page. It's going to take some time, as it's a vintage document. It gathers some indepth technical data about the engine.

Furthermore, I came across a reprint of a reference manual on the industrial use of metals in France (1918): “Métaux et leurs conditions d'emploi dans l'industrie moderne, caractéristiques, essais” - Jean Oertlé, 1918. It has been republished by the Bibliothéque Nationale de France.

And do you know what? You can buy it on Amazon!

For a complete oicture, here's a link to all the “Houille Blanche” bulletins:

https://www.shf-lhb.org/

Houille Blanche - Revue internationale de l'eau” is a French scientific journal published since the early 20th century by the Société Hydrotechnique de France. It's a scientific engineering journal focusing on the use of water as a source of energy and a natural resource. We're very fortunate in that its editions are now available entirely online!

LTM 

Thanks Marty.  I knew there was second PL8 built but had never seen any details.

The Hispano-Suiza 12M was a V-12 that introduced a new cooling system. "Wet liners" brought the cooling water into direct contact with the steel cylinder barrel rather than by screwing it into a water jacket. The header tank for the Hisso is much smaller and the filler neck further aft than on l'Oiseau Blanc.

Renaud,  WOW!  Lots of great information there.  I'll start working up comparisons to the XRF data we have on the artifacts.

I have my doubts that the cylindrical artifact is 12L14.  The XRF software on some of the readings indicated "LA-C steel".  None specifically said 12L14 steel.  12L14 is just one of several LA-C steels.  All LA-C steels have sulphur and phosphorous and I don't see that in the XRF data.
 
It's remarkable that the booklet “Information on the Lorraine 12 Eb 450 hp engine” published by the Centre d'Instruction des Spécialistes de l'Aviation - Ministère de l'Air. (School for training Air Force mechanics between 1916 and 1928.) is handwritten.  The date is perfect, as is the July-August 1921 issue of “La Houille Blanche ‘1 , ’LES PRINPAUX ACIERS DE CONSTRUCTION.

The "special steel" question goes further than the engine cylinders. We have a Spare Parts Manual for the Levasseur PL4 and many components were made of "acier special".  Now we have data on what kinds of "special steel" were available at the time the engine and airframe of the PL8 were under construction.  If our artifacts match those data it will be a huge step forward toward proving we have debris from l'Oiseau Blanc.

Here is the booklet “Information on the Lorraine 12 Eb 450 hp engine” excerpt i was reffering to.

LTM

I share with you my reasoning on the subject. That said, it's just a non-expert's point of view...

For what follows, I'm going to refer to 2 documents:

the booklet “Information on the Lorraine 12 Eb 450 hp engine” published by the Centre d'Instruction des Spécialistes de l'Aviation - Ministère de l'Air. (School for training Air Force mechanics between 1916 and 1928.)

The article published in the July-August 1921 issue of “La Houille Blanche ‘1 , ’LES PRINPAUX ACIERS DE CONSTRUCTION”, by P. Dejean.


Today, standards for the quality and nature of steels (alloyed, non-alloyed, hard and non-hard, ductile and non-ductile, etc.) comply with standardized industrial quality norms. For example, US standard 12L14 is similar to French standard S300pb (European designation: 11SMnPb37 or 1.0737).

S' refers to 'Structure', designating steel for the construction of structures or objects; ;
300 refers to the strength of the material (yield strength expressed in megapascals);
pb' refers to lead.

I'm no specialist, but all this is harmonized via a unified system: the UNS. In the 1920s, I doubt that such international equivalents existed.

From the “Houille Blanche” article, we can see that in France, steels in the 1920s were mostly classified according to their ductility: extra mild, mild (Adx), semi-soft, semi-hard...

Subsequently, they were classified according to their mechanical properties, since this was the main concern in industrial applications. As time went by, the composition of the steel, the alloy, became increasingly important, particularly for the application of heat treatments. Nowadays, the content of various chemical elements is also indicated.

The interest of the “Houille Blanche” article is that it proves the classification in use in France in the early 1920s for the 14 “grades” of steel, for predetermined uses. However, these « grades » are only basic, not comprehensive.

Each forge had its own classification with steels of similar grades...

 
This document tells us that a steel called “semi-soft carbon” (class B) corresponds to a chemical composition mostly close to that of S300pb or 12L14. The phosphorus content is identical (.35), the sulfur content is very similar (.35), as is the carbon content (.15).

Track the others components is not an easy task since no standard classification from chimical composition didn't exist at that time.

To my great regret, for our Lorraine 450hp, I was unable to find any open-source details on the composition of this perticular engine's cylinders.

The manufacturer's service manual is fairly brief on the subject (page 17): “The cylinders, made of special steel, are machined separately and worked as a whole."

In France, at the time, the term 'special steel' meant steel generally alloyed with elements other than carbon and for a specific use...

We can only deduce that each cylinder is machined, milled directly, in the Lorraine workshop, from a steel 'ingot'. These 'ingots' must have been specially ordered directly from a French foundry (St Chamont, Le Creusot, Holtzer, Châtillon, for the best known...). I will try to find out which one was commonly used by Lorraine.
 
On the other hand, the leaflet “Information on the Lorraine 12 Eb 450 hp engine” gives a rather interesting piece of information (page 9):

“In semi-hard, forged steel, taken from the mass and machined separately.”

Now, according to the “Houille Blanche” article, a standard semi-hard steel had the following characteristics in 1920:

generally between 0.28 and 0.34% carbon content;
Phosphorus: 0.035%;
Sulfur: 0.035%;
silicium (between 0.10 and 0.60%).

Lead is not indicated.

Regarding french 'acier spécial' ratings, according to the “Houille Blanche”, there was another 'grade' : The 'F' or, « Mangano-silicieux' (Manganese – Silicious ally Steel ?) which was a typical spécial steel used for aircraft engine's cylinder :

« It is worth noting that this steel, which has been used  for a very long time, received a new application during the war, a new application which has given it a new lease of life. This was its use in aircraft engine cylinders engines. In practice, it was recognized that cylinders made in this way were better able to withstand the high temperatures  than carbon steels of corresponding hardness. »

I found others writings that  supports that statement.

Typical 'F' grade alloy steel composition was as follow (according  the “Houille Blanche ») :

Carbon : 0,40/0,60 %
Silicium : 1,6/2%
Manganese : 0,30/0,50%

However, according to other sources ( “Métaux et leurs conditions d'emploi dans l'industrie moderne, caractéristiques, essais” - Jean Oertlé, 1918), the more frequent use of this special steel used more manganese and less silicium, for reasons of brittleness:

Carbon : 0,30/0,60 %
Silicium : 1,00/2%
Manganese : 0,30/1%

If I understand correctly, in France in 1920, the combined use of silicium and manganese made it possible to use much softer steels for similar applications requiring strength, ductility and good deformation and temperature behavior. This brings us closer to 12L14. 


So it's not at all impossible that French forges and manufacturers were using special steels with chemical characteristics were very close to those of 12L14 as early as 1920.

For Lorraine, it's just a question of finding out which one...

Hoping this personnal guess could help a little.