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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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hardening and annealing 0-1 tool steel.
Howdy folks,
Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been getting is harder than normal , so to test my theory about that being caused at least significantly by the condition of the steel as opposed to alloying variances, I annealed a batch of die plates the other day . I was right about that and my guess is that the mill is cutting mfg costs by not fully annealing the stock that the flat-grinders are being supplied with. According to data from Diehl Steel, the slow cooling should take place at 35 deg F max . per hour from 1475 deg to 1110 deg, which takes roughly... a whole freakin day !. Regardless of why the steel is harder than normal, my concern is about degradation that may occur from the steel spending so much time at elevated temps. I wrapped my parts in ss foil and that did keep them clean, and I am assuming that since these are the directions given for annealing, that it's safe to actually do it; that the steel does maintain it's "hardenability integrity " through the process of annealing and subsequent hardening after cold working. Input?. Thanks, DS |
#2
Posted to rec.crafts.metalworking
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hardening and annealing 0-1 tool steel.
"Dar" wrote in message ... Howdy folks, Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been getting is harder than normal , so to test my theory about that being caused at least significantly by the condition of the steel as opposed to alloying variances, I annealed a batch of die plates the other day . I was right about that and my guess is that the mill is cutting mfg costs by not fully annealing the stock that the flat-grinders are being supplied with. According to data from Diehl Steel, the slow cooling should take place at 35 deg F max . per hour from 1475 deg to 1110 deg, which takes roughly... a whole freakin day !. Regardless of why the steel is harder than normal, my concern is about degradation that may occur from the steel spending so much time at elevated temps. I wrapped my parts in ss foil and that did keep them clean, and I am assuming that since these are the directions given for annealing, that it's safe to actually do it; that the steel does maintain it's "hardenability integrity " through the process of annealing and subsequent hardening after cold working. Input?. Thanks, DS The steel should harden with no problem. Some may question whether you'll have grain growth as a result of the slow cooling, but, IIRC, that shouldn't be a problem because it's below the transition temperature for the entire time. Grain growth wouldn't harm hardenability, but it would harm toughness. In any case, I think anything that happens to the grain is going to be upset when you heat it above the transition temp again to re-harden it, anyway. Considering how careful you're being with the annealing, it ought to be OK. I've hardened plenty of oil-hardening stock but I don't recall ever annealing it, so I'm speaking from theory rather than experience. -- Ed Huntress |
#3
Posted to rec.crafts.metalworking
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hardening and annealing 0-1 tool steel.
Dar, I was using the existing stock of O1 when I first started working at my
job, and had poor and inconsistent results with it all around. I went with A2 for most round items and plates, and have never looked back. The higher cost of the material to the company is now offset by me spending less time dicking with it. I even got brave, and I now make short splined broaches out of or S7, heat them with a torch on a rotating turntable, air quench, reheat slightly to stabilize, and run them. They are around 1/2" diameter being rammed dry through a pilot hole in 3/8" thick ledloy 12L14 or 360 brass by a punch press. No problems. Whenever I use the foil wrap, I put a torn up piece of toilet paper in the bag to ignite and burn off the remaining oxygen in the bag, to create my "inert" atmosphere. RJ "Dar" wrote in message ... Howdy folks, Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been getting is harder than normal , so to test my theory about that being caused at least significantly by the condition of the steel as opposed to alloying variances, I annealed a batch of die plates the other day . I was right about that and my guess is that the mill is cutting mfg costs by not fully annealing the stock that the flat-grinders are being supplied with. According to data from Diehl Steel, the slow cooling should take place at 35 deg F max . per hour from 1475 deg to 1110 deg, which takes roughly... a whole freakin day !. Regardless of why the steel is harder than normal, my concern is about degradation that may occur from the steel spending so much time at elevated temps. I wrapped my parts in ss foil and that did keep them clean, and I am assuming that since these are the directions given for annealing, that it's safe to actually do it; that the steel does maintain it's "hardenability integrity " through the process of annealing and subsequent hardening after cold working. Input?. Thanks, DS |
#4
Posted to rec.crafts.metalworking
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hardening and annealing 0-1 tool steel.
On Apr 4, 10:03*pm, "Ed Huntress" wrote:
"Dar" wrote in message ... Howdy folks, Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been getting is harder than normal , so to test my theory about that being caused at least significantly by the condition of the steel as opposed to alloying variances, I annealed a batch of die plates the other day . I was right *about that and my guess is that the mill is cutting mfg costs by not fully annealing the stock that the flat-grinders are being supplied with. According to data from Diehl Steel, the slow cooling should take place at 35 deg F max . per hour from 1475 deg to 1110 deg, which takes roughly... *a whole freakin day !. Regardless of why the steel is harder than normal, my concern is about degradation that may occur *from the steel spending so much time at elevated temps. I wrapped my parts in ss foil and that did keep them clean, and I am assuming that since these are the directions given for annealing, that it's safe to actually do it; that the steel does maintain it's "hardenability integrity " through the process of annealing and subsequent hardening *after cold working. Input?. Thanks, DS The steel should harden with no problem. Some may question whether you'll have grain growth as a result of the slow cooling, but, IIRC, that shouldn't be a problem because it's below the transition temperature for the entire time. Grain growth wouldn't harm hardenability, but it would harm toughness. In any case, I think anything that happens to the grain is going to be upset when you heat it above the transition temp again to re-harden it, anyway. Considering how careful you're being with the annealing, it ought to be OK.. I've hardened plenty of oil-hardening stock but I don't recall ever annealing it, so I'm speaking from theory rather than experience. -- Ed Huntress- Hide quoted text - - Show quoted text - The thing in the back of my mind I read somewhere is that carbon can leach out at high temps , and it might detriorate the steel and leave it less tough or more fragile than it otherwise would after hardening and tempering . But it sounds like I'll be ok. Thanks, DS |
#5
Posted to rec.crafts.metalworking
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hardening and annealing 0-1 tool steel.
On Apr 5, 6:12*am, "Backlash" wrote:
Dar, I was using the existing stock of O1 when I first started working at my job, and had poor and inconsistent results with it all around. I went with A2 for most round items and plates, and have never looked back. The higher cost of the material to the company is now offset by me spending less time dicking with it. I even got brave, and I now make short splined broaches out of or S7, heat them with a torch on a rotating turntable, air quench, reheat slightly to stabilize, and run them. They are around 1/2" diameter being rammed dry through a pilot hole in 3/8" thick ledloy 12L14 *or 360 brass by a punch press. No problems. Whenever I use the foil wrap, I put a torn up piece of toilet paper in the bag to ignite and burn off the remaining oxygen in the bag, to create my "inert" atmosphere. RJ "Dar" wrote in message ... Howdy folks, Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been getting is harder than normal , so to test my theory about that being caused at least significantly by the condition of the steel as opposed to alloying variances, I annealed a batch of die plates the other day . I was right *about that and my guess is that the mill is cutting mfg costs by not fully annealing the stock that the flat-grinders are being supplied with. According to data from Diehl Steel, the slow cooling should take place at 35 deg F max . per hour from 1475 deg to 1110 deg, which takes roughly... *a whole freakin day !. Regardless of why the steel is harder than normal, my concern is about degradation that may occur *from the steel spending so much time at elevated temps. I wrapped my parts in ss foil and that did keep them clean, and I am assuming that since these are the directions given for annealing, that it's safe to actually do it; that the steel does maintain it's "hardenability integrity " through the process of annealing and subsequent hardening *after cold working. Input?. Thanks, DS- Hide quoted text - - Show quoted text - I tried a piece of A2 or D2 a long time ago and it was too hard to saw efficiently. I make pancake blanking dies and I saw them with jewelers saw blades, so I need soft material, like 0-1 that's properly annealed . Thanks for the tip, and if this hard 0-1 keeps coming at me I may try some air -hard again . Dar http://www.sheltech.net http://www.soundclick.com/darshelton |
#6
Posted to rec.crafts.metalworking
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hardening and annealing 0-1 tool steel.
"Dar" wrote in message ... On Apr 4, 10:03 pm, "Ed Huntress" wrote: "Dar" wrote in message ... Howdy folks, Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been getting is harder than normal , so to test my theory about that being caused at least significantly by the condition of the steel as opposed to alloying variances, I annealed a batch of die plates the other day . I was right about that and my guess is that the mill is cutting mfg costs by not fully annealing the stock that the flat-grinders are being supplied with. According to data from Diehl Steel, the slow cooling should take place at 35 deg F max . per hour from 1475 deg to 1110 deg, which takes roughly... a whole freakin day !. Regardless of why the steel is harder than normal, my concern is about degradation that may occur from the steel spending so much time at elevated temps. I wrapped my parts in ss foil and that did keep them clean, and I am assuming that since these are the directions given for annealing, that it's safe to actually do it; that the steel does maintain it's "hardenability integrity " through the process of annealing and subsequent hardening after cold working. Input?. Thanks, DS The steel should harden with no problem. Some may question whether you'll have grain growth as a result of the slow cooling, but, IIRC, that shouldn't be a problem because it's below the transition temperature for the entire time. Grain growth wouldn't harm hardenability, but it would harm toughness. In any case, I think anything that happens to the grain is going to be upset when you heat it above the transition temp again to re-harden it, anyway. Considering how careful you're being with the annealing, it ought to be OK. I've hardened plenty of oil-hardening stock but I don't recall ever annealing it, so I'm speaking from theory rather than experience. -- Ed Huntress- Hide quoted text - - Show quoted text - The thing in the back of my mind I read somewhere is that carbon can leach out at high temps , and it might detriorate the steel and leave it less tough or more fragile than it otherwise would after hardening and tempering . But it sounds like I'll be ok. Thanks, DS Carbon can indeed oxidize at the surface, but it's slightly less of a problem with oil-hardening than with water-hardening. It actually decarburizes, leaving the steel soft on the surface (called "bark"). However, you want to protect it with a carbon-rich atmosphere. The SS foil will minimize oxidizing. Throwing in some graphite powder, charcoal, or a big pinch of Kasenit will add more security by creating a sacrificial atmosphere of carbon monoxide, should any oxygen get through the foil seams. Someone mentioned throwing in a piece of tissue. I've never heard of that, but it probably would do it , except for the length of time the piece will be heated. Some people wrap the parts in heavy kraft paper. Bone meal is another traditional source of carbon. It doesn't take anything fancy but you have to keep that atmosphere for hours, so make it something that will last. This is why they use graphite boats in traditional tool-hardening applications. With SS foil, the boat isn't necessary. But you still want a source of carbon in there. I don't know the temperature at which you'll be safe from decarb but it's certainly no lower than 700 or 800 deg. F. So it's only a problem in the early stage of the process, if at all. The issue usually comes up in relation to temperatures above transition, and you're *starting* at around the transition temperature. If you get bark, you probably won't know it until after you re-heat-treat the piece. If you've machined the surface off of it (say, 0.010" or more) before heat treatment, the bark will go away and you won't even know you had bark in the first place. -- Ed Huntress |
#7
Posted to rec.crafts.metalworking
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hardening and annealing 0-1 tool steel.
I've been cutting A2 on an upright bandsaw at 125 linear blade feet per
minute for years with an 18 tooth pitch blade, on sections less than about 1/2" . I go a little coarser on the blade pitch for thicker sections. The saw has air blowing into the cut line to extract chips. Love my compressed air! RJ "Dar" wrote in message ... On Apr 5, 6:12 am, "Backlash" wrote: Dar, I was using the existing stock of O1 when I first started working at my job, and had poor and inconsistent results with it all around. I went with A2 for most round items and plates, and have never looked back. The higher cost of the material to the company is now offset by me spending less time dicking with it. I even got brave, and I now make short splined broaches out of or S7, heat them with a torch on a rotating turntable, air quench, reheat slightly to stabilize, and run them. They are around 1/2" diameter being rammed dry through a pilot hole in 3/8" thick ledloy 12L14 or 360 brass by a punch press. No problems. Whenever I use the foil wrap, I put a torn up piece of toilet paper in the bag to ignite and burn off the remaining oxygen in the bag, to create my "inert" atmosphere. RJ "Dar" wrote in message ... Howdy folks, Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been getting is harder than normal , so to test my theory about that being caused at least significantly by the condition of the steel as opposed to alloying variances, I annealed a batch of die plates the other day . I was right about that and my guess is that the mill is cutting mfg costs by not fully annealing the stock that the flat-grinders are being supplied with. According to data from Diehl Steel, the slow cooling should take place at 35 deg F max . per hour from 1475 deg to 1110 deg, which takes roughly... a whole freakin day !. Regardless of why the steel is harder than normal, my concern is about degradation that may occur from the steel spending so much time at elevated temps. I wrapped my parts in ss foil and that did keep them clean, and I am assuming that since these are the directions given for annealing, that it's safe to actually do it; that the steel does maintain it's "hardenability integrity " through the process of annealing and subsequent hardening after cold working. Input?. Thanks, DS- Hide quoted text - - Show quoted text - I tried a piece of A2 or D2 a long time ago and it was too hard to saw efficiently. I make pancake blanking dies and I saw them with jewelers saw blades, so I need soft material, like 0-1 that's properly annealed . Thanks for the tip, and if this hard 0-1 keeps coming at me I may try some air -hard again . Dar http://www.sheltech.net http://www.soundclick.com/darshelton |
#8
Posted to rec.crafts.metalworking
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hardening and annealing 0-1 tool steel.
Also, nothing like spending days making a pair of D2 swager die blocks,
sending them out for controlled heat treating, then finding out that UPS lost them for me. Boy, was I ****ed. Insured, but still ****ed. See http://www.torrington-machinery.com/...ng_swager.html RJ "Backlash" wrote in message . .. I've been cutting A2 on an upright bandsaw at 125 linear blade feet per minute for years with an 18 tooth pitch blade, on sections less than about 1/2" . I go a little coarser on the blade pitch for thicker sections. The saw has air blowing into the cut line to extract chips. Love my compressed air! RJ "Dar" wrote in message ... On Apr 5, 6:12 am, "Backlash" wrote: Dar, I was using the existing stock of O1 when I first started working at my job, and had poor and inconsistent results with it all around. I went with A2 for most round items and plates, and have never looked back. The higher cost of the material to the company is now offset by me spending less time dicking with it. I even got brave, and I now make short splined broaches out of or S7, heat them with a torch on a rotating turntable, air quench, reheat slightly to stabilize, and run them. They are around 1/2" diameter being rammed dry through a pilot hole in 3/8" thick ledloy 12L14 or 360 brass by a punch press. No problems. Whenever I use the foil wrap, I put a torn up piece of toilet paper in the bag to ignite and burn off the remaining oxygen in the bag, to create my "inert" atmosphere. RJ "Dar" wrote in message ... Howdy folks, Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been getting is harder than normal , so to test my theory about that being caused at least significantly by the condition of the steel as opposed to alloying variances, I annealed a batch of die plates the other day . I was right about that and my guess is that the mill is cutting mfg costs by not fully annealing the stock that the flat-grinders are being supplied with. According to data from Diehl Steel, the slow cooling should take place at 35 deg F max . per hour from 1475 deg to 1110 deg, which takes roughly... a whole freakin day !. Regardless of why the steel is harder than normal, my concern is about degradation that may occur from the steel spending so much time at elevated temps. I wrapped my parts in ss foil and that did keep them clean, and I am assuming that since these are the directions given for annealing, that it's safe to actually do it; that the steel does maintain it's "hardenability integrity " through the process of annealing and subsequent hardening after cold working. Input?. Thanks, DS- Hide quoted text - - Show quoted text - I tried a piece of A2 or D2 a long time ago and it was too hard to saw efficiently. I make pancake blanking dies and I saw them with jewelers saw blades, so I need soft material, like 0-1 that's properly annealed . Thanks for the tip, and if this hard 0-1 keeps coming at me I may try some air -hard again . Dar http://www.sheltech.net http://www.soundclick.com/darshelton |
#9
Posted to rec.crafts.metalworking
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hardening and annealing 0-1 tool steel.
"Robert Swinney" wrote in message ... Dunno, Ed! If it wasn't you I'd say ask Ed. Huntress. Anyway, the last 0-1 got had instructions with it to heat 1475F, oil quench and temper at 350 F for 1 hour. Bob Swinney But I'm getting rusty, Bob. I've been away from it for too long. I used to be able to tell what would happen to the grain when you annealed it. Now I'm just trying to sweep away the cobwebs. I also didn't pick up on the fact that these are those thin spring-type die plates. You can't machine the bark off of them, so protecting them well is important. -- Ed Huntress Huntress" wrote in message ... "Dar" wrote in message ... On Apr 4, 10:03 pm, "Ed Huntress" wrote: "Dar" wrote in message ... Howdy folks, Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been getting is harder than normal , so to test my theory about that being caused at least significantly by the condition of the steel as opposed to alloying variances, I annealed a batch of die plates the other day . I was right about that and my guess is that the mill is cutting mfg costs by not fully annealing the stock that the flat-grinders are being supplied with. According to data from Diehl Steel, the slow cooling should take place at 35 deg F max . per hour from 1475 deg to 1110 deg, which takes roughly... a whole freakin day !. Regardless of why the steel is harder than normal, my concern is about degradation that may occur from the steel spending so much time at elevated temps. I wrapped my parts in ss foil and that did keep them clean, and I am assuming that since these are the directions given for annealing, that it's safe to actually do it; that the steel does maintain it's "hardenability integrity " through the process of annealing and subsequent hardening after cold working. Input?. Thanks, DS The steel should harden with no problem. Some may question whether you'll have grain growth as a result of the slow cooling, but, IIRC, that shouldn't be a problem because it's below the transition temperature for the entire time. Grain growth wouldn't harm hardenability, but it would harm toughness. In any case, I think anything that happens to the grain is going to be upset when you heat it above the transition temp again to re-harden it, anyway. Considering how careful you're being with the annealing, it ought to be OK. I've hardened plenty of oil-hardening stock but I don't recall ever annealing it, so I'm speaking from theory rather than experience. -- Ed Huntress- Hide quoted text - - Show quoted text - The thing in the back of my mind I read somewhere is that carbon can leach out at high temps , and it might detriorate the steel and leave it less tough or more fragile than it otherwise would after hardening and tempering . But it sounds like I'll be ok. Thanks, DS Carbon can indeed oxidize at the surface, but it's slightly less of a problem with oil-hardening than with water-hardening. It actually decarburizes, leaving the steel soft on the surface (called "bark"). However, you want to protect it with a carbon-rich atmosphere. The SS foil will minimize oxidizing. Throwing in some graphite powder, charcoal, or a big pinch of Kasenit will add more security by creating a sacrificial atmosphere of carbon monoxide, should any oxygen get through the foil seams. Someone mentioned throwing in a piece of tissue. I've never heard of that, but it probably would do it , except for the length of time the piece will be heated. Some people wrap the parts in heavy kraft paper. Bone meal is another traditional source of carbon. It doesn't take anything fancy but you have to keep that atmosphere for hours, so make it something that will last. This is why they use graphite boats in traditional tool-hardening applications. With SS foil, the boat isn't necessary. But you still want a source of carbon in there. I don't know the temperature at which you'll be safe from decarb but it's certainly no lower than 700 or 800 deg. F. So it's only a problem in the early stage of the process, if at all. The issue usually comes up in relation to temperatures above transition, and you're *starting* at around the transition temperature. If you get bark, you probably won't know it until after you re-heat-treat the piece. If you've machined the surface off of it (say, 0.010" or more) before heat treatment, the bark will go away and you won't even know you had bark in the first place. -- Ed Huntress |
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