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#11
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stainless steel chain
On Fri, 27 Mar 2015 13:32:42 +1000, James
wrote: On 23/03/15 21:42, Doug Cimperman wrote: On 3/15/2015 5:45 AM, Emanuel Berg wrote: I got hold of a stainless steel chain a while back and the guy said there was no need to oil it because of the stainlessness. Is that true? And, when I examine the chain now, the plates are indeed rust free, but it appears not so the cylinders in between. Is this common? If so, is it not false advertising? That is false. Stainless steel suffers galvanic corrosion so easily in salt water that it isn't allowed to be used below the waterline on most types of oceangoing ship hulls. http://www.worldstainless.org/transp...s/shipbuilding http://www.dieselduck.info/machine/0.../corrosion.htm It seems that on ships hulls it is the low oxygen environment that causes most of the problem. The protective layer cannot form fast enough. On a bicycle chain I doubt this is an issue, unless you throw the bike in the sea... Yes, low oxygen is the base reason that stuff under water may corrode more than on shore but it is somewhat relative. The prop shaft on my boar was about 6 feet below the waterline and I had the boat nearly 20 years... with the same prop shaft. The rollers are likely hardened steel and not so stainless. They could be made from some allow of stainless. The higher series of stainless can be pretty hard. The AUS series have from .65% to 1.1% carbon and there are other grades having even more carbon. For example: CPM S125V, contains 3.25% carbon, 14% chromium and 12% Vanadium and other alloying elements.Exceptionally high wear resistance, making it difficult to process and machine for knife makers. But, on the other hand, I suspect that a chain using these materials might be a bit expensive :-) -- Cheers, John B. |
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#12
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stainless steel chain
On Sat, 28 Mar 2015 00:03:38 +0000, Phil W Lee
wrote: John B. Slocomb considered Fri, 27 Mar 2015 07:10:26 +0700 the perfect time to write: On Thu, 26 Mar 2015 16:02:15 -0500, Doug Cimperman wrote: On 3/23/2015 8:55 AM, John B. Slocomb wrote: On Mon, 23 Mar 2015 06:42:39 -0500, Doug Cimperman wrote: That is false. Stainless steel suffers galvanic corrosion so easily in salt water that it isn't allowed to be used below the waterline on most types of oceangoing ship hulls. http://www.worldstainless.org/transp...s/shipbuilding http://www.dieselduck.info/machine/0.../corrosion.htm Strange. I lived on a auxiliary powered sail boat for about 15 years and was never aware that stainless wasn't to be used on a boat.... Not a boat, a ship. And not the whole ship, just the submerged part of the hull. Most enclosed-hull boats I've seen had all kinds of stainless deck fittings and railings. Those are safer to fail and easier to fix than the underside of a 200,000 ton bulk carrier ship tho. The submerged portions of a ship's hull are not made from "stainless steel" for the simple reason that it "costs like hell" to do that. Instead the hull is made from more normal (read cheaper) steel and made thicker by a "corrosion factor" to allow for the thinning of the plating due to corrosion over the life of the vessel. If "stainless steel" were to be reduced in price (probably not likely) and if it became cost wise to do so ships would be built from it. It might be noted that stainless steel yacht hulls have been built and it is rarely done due to cost reasons. Current stainless scrap prices are about $1,560/long ton while common steel scrap is $260, so using that example your boat hull would cost you 6 times as much if made from stainless. The Emma Maersk (the largest ship ever built at the time) cost US $145,000,000 to build. Six times that price and you are talking real money... To be fair, only a fraction of that is the cost of the material. OTOH, it's going to be more expensive to work with stainless (but not 6 times more). Some naval ships are made of exotic materials, but corrosion resistance isn't usually the reason, although it may be a useful side-effect. You are correct, in essence, but I can tell you that for smaller vessels, say 50 - 70 ft. the yards will quote a preliminary, "ball park", cost based on the amount of steel that is required. I'm sure that labour is costed into their estimate but the cost of plate is a major part of the cost. One boat I talked to a yard about wasn't required to be certified and the yard suggested using Polish steel which would reduce the price considerably. As for exotic metals in navel vessels, wasn't the aluminum superstructure the reason the British destroyer was sunk, off the Falklands, by a single (French) rocket? -- Cheers, John B. |
#13
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stainless steel chain
On Sat, 28 Mar 2015 00:05:33 +0000, Phil W Lee
wrote: John B. Slocomb considered Fri, 27 Mar 2015 18:27:39 +0700 the perfect time to write: On Fri, 27 Mar 2015 13:32:42 +1000, James wrote: On 23/03/15 21:42, Doug Cimperman wrote: On 3/15/2015 5:45 AM, Emanuel Berg wrote: I got hold of a stainless steel chain a while back and the guy said there was no need to oil it because of the stainlessness. Is that true? And, when I examine the chain now, the plates are indeed rust free, but it appears not so the cylinders in between. Is this common? If so, is it not false advertising? That is false. Stainless steel suffers galvanic corrosion so easily in salt water that it isn't allowed to be used below the waterline on most types of oceangoing ship hulls. http://www.worldstainless.org/transp...s/shipbuilding http://www.dieselduck.info/machine/0.../corrosion.htm It seems that on ships hulls it is the low oxygen environment that causes most of the problem. The protective layer cannot form fast enough. On a bicycle chain I doubt this is an issue, unless you throw the bike in the sea... Yes, low oxygen is the base reason that stuff under water may corrode more than on shore but it is somewhat relative. The prop shaft on my boar was about 6 feet below the waterline and I had the boat nearly 20 years... with the same prop shaft. The rollers are likely hardened steel and not so stainless. They could be made from some allow of stainless. The higher series of stainless can be pretty hard. The AUS series have from .65% to 1.1% carbon and there are other grades having even more carbon. For example: CPM S125V, contains 3.25% carbon, 14% chromium and 12% Vanadium and other alloying elements.Exceptionally high wear resistance, making it difficult to process and machine for knife makers. But, on the other hand, I suspect that a chain using these materials might be a bit expensive :-) You might as well use titanium and have done with it. The trouble with generalizing about metals is that simply saying Titanium" isn't very descriptive. I did a little work on the SR-71 and the titanium skin was much like the softer grades of stainless to work with. -- Cheers, John B. |
#14
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stainless steel chain
On 3/27/2015 7:05 PM, Phil W Lee wrote:
John B. Slocomb considered Fri, 27 Mar 2015 18:27:39 +0700 the perfect time to write: On Fri, 27 Mar 2015 13:32:42 +1000, James wrote: On 23/03/15 21:42, Doug Cimperman wrote: On 3/15/2015 5:45 AM, Emanuel Berg wrote: I got hold of a stainless steel chain a while back and the guy said there was no need to oil it because of the stainlessness. Is that true? And, when I examine the chain now, the plates are indeed rust free, but it appears not so the cylinders in between. Is this common? If so, is it not false advertising? That is false. Stainless steel suffers galvanic corrosion so easily in salt water that it isn't allowed to be used below the waterline on most types of oceangoing ship hulls. http://www.worldstainless.org/transp...s/shipbuilding http://www.dieselduck.info/machine/0.../corrosion.htm It seems that on ships hulls it is the low oxygen environment that causes most of the problem. The protective layer cannot form fast enough. On a bicycle chain I doubt this is an issue, unless you throw the bike in the sea... Yes, low oxygen is the base reason that stuff under water may corrode more than on shore but it is somewhat relative. The prop shaft on my boar was about 6 feet below the waterline and I had the boat nearly 20 years... with the same prop shaft. The rollers are likely hardened steel and not so stainless. They could be made from some allow of stainless. The higher series of stainless can be pretty hard. The AUS series have from .65% to 1.1% carbon and there are other grades having even more carbon. For example: CPM S125V, contains 3.25% carbon, 14% chromium and 12% Vanadium and other alloying elements.Exceptionally high wear resistance, making it difficult to process and machine for knife makers. But, on the other hand, I suspect that a chain using these materials might be a bit expensive :-) You might as well use titanium and have done with it. That's been done. Badly; fast wear, high cost and Ti is quite reactive/corrodable where the surface sees abrasion. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#15
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stainless steel chain
On Sun, 29 Mar 2015 23:22:31 +0100, Phil W Lee
wrote: John B. Slocomb considered Sat, 28 Mar 2015 18:10:23 +0700 the perfect time to write: On Sat, 28 Mar 2015 00:03:38 +0000, Phil W Lee wrote: John B. Slocomb considered Fri, 27 Mar 2015 07:10:26 +0700 the perfect time to write: On Thu, 26 Mar 2015 16:02:15 -0500, Doug Cimperman wrote: On 3/23/2015 8:55 AM, John B. Slocomb wrote: On Mon, 23 Mar 2015 06:42:39 -0500, Doug Cimperman wrote: That is false. Stainless steel suffers galvanic corrosion so easily in salt water that it isn't allowed to be used below the waterline on most types of oceangoing ship hulls. http://www.worldstainless.org/transp...s/shipbuilding http://www.dieselduck.info/machine/0.../corrosion.htm Strange. I lived on a auxiliary powered sail boat for about 15 years and was never aware that stainless wasn't to be used on a boat.... Not a boat, a ship. And not the whole ship, just the submerged part of the hull. Most enclosed-hull boats I've seen had all kinds of stainless deck fittings and railings. Those are safer to fail and easier to fix than the underside of a 200,000 ton bulk carrier ship tho. The submerged portions of a ship's hull are not made from "stainless steel" for the simple reason that it "costs like hell" to do that. Instead the hull is made from more normal (read cheaper) steel and made thicker by a "corrosion factor" to allow for the thinning of the plating due to corrosion over the life of the vessel. If "stainless steel" were to be reduced in price (probably not likely) and if it became cost wise to do so ships would be built from it. It might be noted that stainless steel yacht hulls have been built and it is rarely done due to cost reasons. Current stainless scrap prices are about $1,560/long ton while common steel scrap is $260, so using that example your boat hull would cost you 6 times as much if made from stainless. The Emma Maersk (the largest ship ever built at the time) cost US $145,000,000 to build. Six times that price and you are talking real money... To be fair, only a fraction of that is the cost of the material. OTOH, it's going to be more expensive to work with stainless (but not 6 times more). Some naval ships are made of exotic materials, but corrosion resistance isn't usually the reason, although it may be a useful side-effect. You are correct, in essence, but I can tell you that for smaller vessels, say 50 - 70 ft. the yards will quote a preliminary, "ball park", cost based on the amount of steel that is required. I'm sure that labour is costed into their estimate but the cost of plate is a major part of the cost. One boat I talked to a yard about wasn't required to be certified and the yard suggested using Polish steel which would reduce the price considerably. As for exotic metals in navel vessels, wasn't the aluminum superstructure the reason the British destroyer was sunk, off the Falklands, by a single (French) rocket? Incorrect - HMS Sheffield's superstructure was entirely steel, in common with all other type 42 destroyers, The main reason she was lost is that the Exocet went straight through the ships high pressure water main (leading to a loss of fire-fighting capability), and embedded itself in the ready use diesel tanks in the engine room with it's rocket motor propellant still burning. See http://en.wikipedia.org/wiki/HMS_Sheffield_%28D80%29 As part of the screening force for the flagship, HMS Hermes, she did her job, by "catching the bullet", and although it would have been preferable to have shot it down, the level of surprise was too great. I know one of her crew from the time, so have heard it first-hand even before it was declassified. Interesting. I don't remember where I read it but I do remember it was alleged that the aluminum superstructure was the problem but from your description it appears that the rocket must have hit the hull, not he superstructure - ready use diesel tanks, etc. Aluminium construction has been implicated in other shipboard fires though. Of course, if weight reduction is the principle objective, why not use magnesium? :-D It's worth bearing in mind that the use of aluminium is also the reason that many naval vessels were spared being sunk by magnetic weapons (many minesweepers have been built from it), and even more exotic materials are still in use for their benefit in reducing the chance of detection by magnetic anomaly effects in strategic systems. If I remember correctly the British had wooden hull mine sweepers in WW II. So there are positives and negatives to almost any material. And, as they say, no plan survives first contact with the enemy! -- Cheers, John B. |
#16
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stainless steel chain
On 30/03/2015 11:34 AM, John B. Slocomb wrote:
On Sun, 29 Mar 2015 23:22:31 +0100, Phil W Lee wrote: John B. Slocomb considered Sat, 28 Mar 2015 18:10:23 +0700 the perfect time to write: On Sat, 28 Mar 2015 00:03:38 +0000, Phil W Lee wrote: John B. Slocomb considered Fri, 27 Mar 2015 07:10:26 +0700 the perfect time to write: On Thu, 26 Mar 2015 16:02:15 -0500, Doug Cimperman wrote: On 3/23/2015 8:55 AM, John B. Slocomb wrote: On Mon, 23 Mar 2015 06:42:39 -0500, Doug Cimperman wrote: That is false. Stainless steel suffers galvanic corrosion so easily in salt water that it isn't allowed to be used below the waterline on most types of oceangoing ship hulls. http://www.worldstainless.org/transp...s/shipbuilding http://www.dieselduck.info/machine/0.../corrosion.htm Strange. I lived on a auxiliary powered sail boat for about 15 years and was never aware that stainless wasn't to be used on a boat.... Not a boat, a ship. And not the whole ship, just the submerged part of the hull. Most enclosed-hull boats I've seen had all kinds of stainless deck fittings and railings. Those are safer to fail and easier to fix than the underside of a 200,000 ton bulk carrier ship tho. The submerged portions of a ship's hull are not made from "stainless steel" for the simple reason that it "costs like hell" to do that. Instead the hull is made from more normal (read cheaper) steel and made thicker by a "corrosion factor" to allow for the thinning of the plating due to corrosion over the life of the vessel. If "stainless steel" were to be reduced in price (probably not likely) and if it became cost wise to do so ships would be built from it. It might be noted that stainless steel yacht hulls have been built and it is rarely done due to cost reasons. Current stainless scrap prices are about $1,560/long ton while common steel scrap is $260, so using that example your boat hull would cost you 6 times as much if made from stainless. The Emma Maersk (the largest ship ever built at the time) cost US $145,000,000 to build. Six times that price and you are talking real money... To be fair, only a fraction of that is the cost of the material. OTOH, it's going to be more expensive to work with stainless (but not 6 times more). Some naval ships are made of exotic materials, but corrosion resistance isn't usually the reason, although it may be a useful side-effect. You are correct, in essence, but I can tell you that for smaller vessels, say 50 - 70 ft. the yards will quote a preliminary, "ball park", cost based on the amount of steel that is required. I'm sure that labour is costed into their estimate but the cost of plate is a major part of the cost. One boat I talked to a yard about wasn't required to be certified and the yard suggested using Polish steel which would reduce the price considerably. As for exotic metals in navel vessels, wasn't the aluminum superstructure the reason the British destroyer was sunk, off the Falklands, by a single (French) rocket? Incorrect - HMS Sheffield's superstructure was entirely steel, in common with all other type 42 destroyers, The main reason she was lost is that the Exocet went straight through the ships high pressure water main (leading to a loss of fire-fighting capability), and embedded itself in the ready use diesel tanks in the engine room with it's rocket motor propellant still burning. See http://en.wikipedia.org/wiki/HMS_Sheffield_%28D80%29 As part of the screening force for the flagship, HMS Hermes, she did her job, by "catching the bullet", and although it would have been preferable to have shot it down, the level of surprise was too great. I know one of her crew from the time, so have heard it first-hand even before it was declassified. Interesting. I don't remember where I read it but I do remember it was alleged that the aluminum superstructure was the problem but from your description it appears that the rocket must have hit the hull, not he superstructure - ready use diesel tanks, etc. Aluminium construction has been implicated in other shipboard fires though. Of course, if weight reduction is the principle objective, why not use magnesium? :-D It's worth bearing in mind that the use of aluminium is also the reason that many naval vessels were spared being sunk by magnetic weapons (many minesweepers have been built from it), and even more exotic materials are still in use for their benefit in reducing the chance of detection by magnetic anomaly effects in strategic systems. If I remember correctly the British had wooden hull mine sweepers in WW II. The US Navy has a class of wooden hull minesweepers now, the Avenger class built in the 80's and 90's. http://www.dailymail.co.uk/news/arti...ismantled.html for the sad fate of one which struck a reef in the Philippines just over two years ago. Four Officers including the Captain carried the can for failure to adhere to correct navigating procedures. PH |
#17
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stainless steel chain
On Mon, 30 Mar 2015 05:22:00 +0100, Phil W Lee
wrote: John B. Slocomb considered Mon, 30 Mar 2015 08:34:55 +0700 the perfect time to write: On Sun, 29 Mar 2015 23:22:31 +0100, Phil W Lee wrote: John B. Slocomb considered Sat, 28 Mar 2015 18:10:23 +0700 the perfect time to write: On Sat, 28 Mar 2015 00:03:38 +0000, Phil W Lee wrote: John B. Slocomb considered Fri, 27 Mar 2015 07:10:26 +0700 the perfect time to write: On Thu, 26 Mar 2015 16:02:15 -0500, Doug Cimperman wrote: On 3/23/2015 8:55 AM, John B. Slocomb wrote: On Mon, 23 Mar 2015 06:42:39 -0500, Doug Cimperman wrote: That is false. Stainless steel suffers galvanic corrosion so easily in salt water that it isn't allowed to be used below the waterline on most types of oceangoing ship hulls. http://www.worldstainless.org/transp...s/shipbuilding http://www.dieselduck.info/machine/0.../corrosion.htm Strange. I lived on a auxiliary powered sail boat for about 15 years and was never aware that stainless wasn't to be used on a boat.... Not a boat, a ship. And not the whole ship, just the submerged part of the hull. Most enclosed-hull boats I've seen had all kinds of stainless deck fittings and railings. Those are safer to fail and easier to fix than the underside of a 200,000 ton bulk carrier ship tho. The submerged portions of a ship's hull are not made from "stainless steel" for the simple reason that it "costs like hell" to do that. Instead the hull is made from more normal (read cheaper) steel and made thicker by a "corrosion factor" to allow for the thinning of the plating due to corrosion over the life of the vessel. If "stainless steel" were to be reduced in price (probably not likely) and if it became cost wise to do so ships would be built from it. It might be noted that stainless steel yacht hulls have been built and it is rarely done due to cost reasons. Current stainless scrap prices are about $1,560/long ton while common steel scrap is $260, so using that example your boat hull would cost you 6 times as much if made from stainless. The Emma Maersk (the largest ship ever built at the time) cost US $145,000,000 to build. Six times that price and you are talking real money... To be fair, only a fraction of that is the cost of the material. OTOH, it's going to be more expensive to work with stainless (but not 6 times more). Some naval ships are made of exotic materials, but corrosion resistance isn't usually the reason, although it may be a useful side-effect. You are correct, in essence, but I can tell you that for smaller vessels, say 50 - 70 ft. the yards will quote a preliminary, "ball park", cost based on the amount of steel that is required. I'm sure that labour is costed into their estimate but the cost of plate is a major part of the cost. One boat I talked to a yard about wasn't required to be certified and the yard suggested using Polish steel which would reduce the price considerably. As for exotic metals in navel vessels, wasn't the aluminum superstructure the reason the British destroyer was sunk, off the Falklands, by a single (French) rocket? Incorrect - HMS Sheffield's superstructure was entirely steel, in common with all other type 42 destroyers, The main reason she was lost is that the Exocet went straight through the ships high pressure water main (leading to a loss of fire-fighting capability), and embedded itself in the ready use diesel tanks in the engine room with it's rocket motor propellant still burning. See http://en.wikipedia.org/wiki/HMS_Sheffield_%28D80%29 As part of the screening force for the flagship, HMS Hermes, she did her job, by "catching the bullet", and although it would have been preferable to have shot it down, the level of surprise was too great. I know one of her crew from the time, so have heard it first-hand even before it was declassified. Interesting. I don't remember where I read it but I do remember it was alleged that the aluminum superstructure was the problem but from your description it appears that the rocket must have hit the hull, not he superstructure - ready use diesel tanks, etc. About 8ft above the waterline. The thing about the aluminium superstructure was a common allegation, which may have been "allowed to circulate", although I doubt if the Argentinians were taken in by it - they had a pair of type 42s they'd bought from us, although their two were specified slightly differently from any of ours. I doubt if we wanted them to know that their warhead hadn't actually detonated, and wanted to give the idea that the Exocet wouldn't have been as effective against larger targets. But once you've got a mixed rocket fuel and diesel fire below decks amidships, and no water to fight it, you're doing well just to save the bulk of the crew. 20 KIA and 26 injured (one seriously) out of 287 is a credit to the rest of the crew, given the conditions they were fighting the fire under. Aluminium construction has been implicated in other shipboard fires though. Of course, if weight reduction is the principle objective, why not use magnesium? :-D It's worth bearing in mind that the use of aluminium is also the reason that many naval vessels were spared being sunk by magnetic weapons (many minesweepers have been built from it), and even more exotic materials are still in use for their benefit in reducing the chance of detection by magnetic anomaly effects in strategic systems. Someone commented that the sale of exocet missiles probably took a big jump within hours :-) If I remember correctly the British had wooden hull mine sweepers in WW II. I think most people did back then, although we also had some concrete ones. Aluminium was too valuable for aircraft use to be used for shipbuilding in WW2. And, there are a lot of things to go wrong with aluminum hulled power boats. So there are positives and negatives to almost any material. And, as they say, no plan survives first contact with the enemy! -- Cheers, John B. |
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