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Posted: 3/13/2009 11:57:51 AM EDT
| What kind of metal is inconel? Want to design my own can. Thinkig about inconel but I dont know much about it. Trying to do some research on what matieral would be best for .223 or .308 cans. |
| Dude, inconel is VERY VERY expensive. You need to look at other options. I sell steel here in OKC and I promise you're gonna have a VERY expensive project on your hands if you bring in inconel. If you need any other options like A36 carbon, stainless, or aluminum then I can help. Just shoot me an email. |
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Errosion and peening at the baffle aperture are the major side effects of fireing being countered by baffle materials such as inconel.
Interestingly, 17-4 PH Stainless steel has better hardness, tensile, and yield strengths. I talked to George at HTG who uses it for his blast baffles, and he's done some considerable research into metals and their properties prior to selecting 17-4 PH for blast baffles. If you look at how 17-4PH is affected by short term exposure to very extreme temperatures, the strength loss results in a product that is still approximately as strong and hard as inconel. These temps are 1600 degrees- a temperature that the silencer simply should not reach, and time of exposure in the test I saw with those results was 10 minutes, a duration in time that I don't feel the silencer would sustain at that temperature under anything less than sustained fully automatic fire from a belt fed machine gun. Try reaching and sustaining that for 10 minutes under normal use with a 7 30 round magazine combat load. Not going to happen. In talking to an engineer friend of mine who works in Hydraulics, he said most likely the reason to use inconel is marketing. According to him it is very common for companies competing to select more expensive materials for marketing reasons. The material probably isn't neccessary. Looking at Eurpopean countries making silencers of 300 series stainless, and sometimes carbon steels, you will begin to strongly suspect marketing as the root cause for inconel in anything other than a blast baffle. Another reason to use inconel may be for applications where material thickness is going to be reduced for weight reduction to the point that the resultant silencer is as durable or even less durable than a slightly heavier silencer made of stainless steel. Ops has long made excellent silencers that hold up great without using inconel. Gemtech uses a small inconel insert in the stainless blast baffle, and the rest of baffles are stainless. There are multiple ways to skin the cat in the material selection game. if you look in the property data sheets here you'll see what I'm talking about- The strength properties of 17-4 are high, and it's use in the surefire muzzle breaks which mount the inconel baffled silencers seems to suggest that operating principle is sound given that the muzzle break baffles inside the silencer are abused as heavily as the baffles of the silencer- erosion and peening are equally significant in that application. AK STEEL 17-4 |
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C__ F
400 752 Red heat, visible in the dark 474 885 Red heat, visible in the twilight 525 975 Red heat, visible in the daylight 581 1077 Red heat, visible in the sunlight 700 1292 Dark red 800 1472 Dull cherry-red 900 1652 Cherry-red 1000 1832 Bright cherry-red 1100 2012 Orange-red “{*} When's the last time you saw a silencer glow red in daylight? When have you seen one glow cherry red in sunlight? These operating temps just aren't happening 99% of the time. Nevermind the fact that you would have to have the can glowing cherry red in sunlight for 10 minutes to significantly weaken 17-4 and even then it's significantly stronger and harder than 316L. |
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Hmm, interesting. Does 17-4 weld good? And whats a good 300 series SS that welds good and would be good for a 7.62 suppressor? If I ever get around to even making this thing, I wont be abusing it. It will go on a .308 AR rifle. It does- I think 311 rod should weld it to 316L and thats a good tube material similar to 304L only with slightly better corrosion resistance. If you do build it, the 17-4 gets good properties from an H 900 heat treat which is just an hour at 900 degrees in air, followed I believe by a 4 hour cooling process. I'm beginning to think press fitting a baffle stack and circumferentially welding the ends is the best way to build a welded suppressor. Obviously though- the reason companies exist is because they make a product that provides a good value- and those products are almost always better than something an individual could build for themself, so you may want to look hard at what is availible before building your own. A product is like a road map of lessons learned through years of experience and lots of money spent and hours worked. The successful performance of the product is often a product of its position atop a pile of spent R&D money. |
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Hmm, interesting. Does 17-4 weld good? And whats a good 300 series SS that welds good and would be good for a 7.62 suppressor? If I ever get around to even making this thing, I wont be abusing it. It will go on a .308 AR rifle. It does- I think 311 rod should weld it to 316L and thats a good tube material similar to 304L only with slightly better corrosion resistance. If you do build it, the 17-4 gets good properties from an H 900 heat treat which is just an hour at 900 degrees in air, followed I believe by a 4 hour cooling process. I'm beginning to think press fitting a baffle stack and circumferentially welding the ends is the best way to build a welded suppressor. Obviously though- the reason companies exist is because they make a product that provides a good value- and those products are almost always better than something an individual could build for themself, so you may want to look hard at what is availible before building your own. A product is like a road map of lessons learned through years of experience and lots of money spent and hours worked. The successful performance of the product is often a product of its position atop a pile of spent R&D money. Greeno, What happens when you get 17-4 hot and cool it rapidly, like in the air at a range ? Or a dunk into water for a refill ? Here's a hint - H900 no more :) And it's not quite as appealing anymore ! |
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Errosion and peening at the baffle aperture are the major side effects of fireing being countered by baffle materials such as inconel. In talking to an engineer friend of mine who works in Hydraulics, he said most likely the reason to use inconel is marketing. According to him it is very common for companies competing to select more expensive materials for marketing reasons. The material probably isn't neccessary. Looking at Eurpopean countries making silencers of 300 series stainless, and sometimes carbon steels, you will begin to strongly suspect marketing as the root cause for inconel in anything other than a blast baffle. Another reason to use inconel may be for applications where material thickness is going to be reduced for weight reduction to the point that the resultant silencer is as durable or even less durable than a slightly heavier silencer made of stainless steel. Ops has long made excellent silencers that hold up great without using inconel. Gemtech uses a small inconel insert in the stainless blast baffle, and the rest of baffles are stainless. There are multiple ways to skin the cat in the material selection game. AK STEEL 17-4 Oh really? You say some dumb stuff on here but damn. If it was just a marketing ploy they could say "insert any cheaper metal here" is the best as a a marketing ploy, sell at a reduced cost, making more profit, vs. using the expensive stuff to start with. So your saying some of the best in the business are just using inconel for the price? Its used for a reason, because its the best application for what the can is designed for. Ops doesn't use it because they don't need it for what their can is designed. KAC does use it and they dont give a shit about price because they are selling to the mil. They use it because its the best. 
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The Ak steel link shows you what happens to it, it gets weaker, but is still several times the strength of 316 and stabilizes there. The annealed 17-4 has a hardness in the 36RC range- H900 in the 44RC range. Annealed 718 inconel is 25RC, age hardened is 38+RC, but the age hardening that lends itself to silencers (IE resists hot cracking) is not the harder condition of inconel in the mid 40's on the RC scale but is the ~38RC condition.
I'm sure you came over from some bullshit post on silencer talk where a company defended it's marketing strategy with both coolaid spray guns blazing, but you're simply not seeing the truth. The metals are more similar than people want to admit for the application to silencers. In other words annealed 17-4 is still quite hard at 36RC , compared to 304 or 316 which don't even reach the RC scale, but sit at around 90 RB. The H900 treatment gives you better qualities than inconel if you keep the silencer below 900 F, and if you exceed 900F, the worst that can happen is a return to the annealed condition (at worst) which is only slightly less ideal than age-hardened inconel. Most users will not exceed 900F, and those that do will not likely be able to sustain 1600F (glowing bright red in sunlight) for 10 minutes straight, so the material will most likely remain stronger and harder than annealed 17-4. The point is the hardness is helping the baffle resist peening and errosion at the bore, and 17-4 is doing a damn good job of it for the money, and making a strong argument to question why companies use inconel at 5 times the cost, for 10%-20% more ideal properties that apply to probably 1-3% of end users fire schedules. All this while other companies produce similarly military successful silencers of 300 series stainless steel. If you heat and water quench 17-4 that could cause hot cracking, similar to what can happen to 718 inconel in the same conditions. If you water quench a hot silencer, you are a metalurgical idiot. Water quenching is stupid and can damage a hot silencer. Inconel like most other high strength/high hardness materials, including 17-4 has a higher likelyhood of hot cracking than a softer alloy like 304, but then the major problem is baffle errosion, not so much hot cracking, because most people air cool silencers rather than dunking them in water with disregard for the effects of rapid uneven cooling on hard materials. |
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