EdouardG
344
Here is a test that's better than a thousand words:
Jul 31, 2009,04:06 AM
Hi all,
Just wanted to share something very interesting with you.
A french forum member, called Jean-Michel, made a very interesting test.
He decided to evaluate how hard is the 904L compared to 316L in some different acids...
This is exactly what he did:
Protocol of test: ageing and accelerated corrosion of various alloys: extract of the various tests carried out
30 minutes 120°C 100% of moisture at saline saturation
24 hours in the acid sulfochromic
24 hours in the acid chloridric
48 hours in ammonium bifluoride at saturation
Result….
Credits: Jean-Michel
Thanks for viewing.
Comments:
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904L steel
By: rick2 : July 27th, 2009-17:46
More resistant to corrosion than 316L, but that is on the Rolex website. Same as far as scratch resistance. Funny thing is the nickel content is higher in 904L than 316L. Rolex simply could have stayed with 316L, but just wanted to show they could work 90...
904L
By: BDLJ : July 27th, 2009-20:09
Is better at resisting pitting and crevice corrosion. (ie, corrosion that occurs in the gaps and slots around gaskets where the lack of oxygen means that the protective oxidised layer cannot form). 904L has a higher PRE (Pitting Resistance) number than 31...
Not sure.
By: BDLJ : July 27th, 2009-23:29
I thought the Egiziano was in Stainless steel (the replicas are titanium, though?). Titanium was pretty rare and exotic stuff in the 50's. It was mainly confined to aerospace activities. Makes you wonder where they got their hands on some...? Of the produ...
TIMET
By: BDLJ : July 28th, 2009-17:47
Hi Aaron, I think the first to produce commercial (well, semi-commercial, it was mainly for military/strategic purposes) was TIMET in 1950/1. They refined and commercialised the Kroll process that you described above. Interestingly, by '53 production was ...
Seiko Titanium Dive watch
By: rick2 : July 28th, 2009-14:49
The Panerai Radiomir Egiziano was made for the Egiziano (Egyptian) Navy in 1956. Reference # was GPF 2/56, 60 mm Stainless Steel dive watch. Some 50 were supposedly made. Seiko claims in 1975 to have made the first titanium case dive watch. Reference # 61...
Do you mean the...
By: BDLJ : July 28th, 2009-17:57
Seiko 6159-701x? That's a dream of mine. Hard to find one without a dinged up bezel. I couldn't remember whether it was the first titanium case or the first ceramic shroud. It's both. The 6159 is a 36,600 beat movement - fundamentally a GS movement with l...
6159-022
By: rick2 : July 29th, 2009-13:34
No, the ref. is 6159-022, and as SJX posted on this thread, this watch had a ceramic shell, over TITANIUM! Watch also employed a rubber strap, especially designed to reduce constriction on the wet suit. No HEV for saturation dives. A special rubber gasket...
904L v 316L
By: BDLJ : July 27th, 2009-23:04
Well, I'm not sure. According to my Materials Handbook, 904L is 23-28% Nickel, while 316L is 10-14%. So twice the amount of Nickel. So I guess if the 316L gives you allergy troubles, the 904L is going to be worse. This poses another question: what are the...
+ 1
By: rene.chimal : July 28th, 2009-15:13
I think the same thing you Nicolas, I believe the cases along with the bracelets will be 904L, imagine an advertisement stating that Rolex uses 904L alone in the cases but not the bracelets, anyway intereante would know the truth ... . Best Rene