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#32
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Aluminium or Chromoly frame?
On 21/11/2016 3:39 PM, AMuzi wrote:
On 11/21/2016 12:53 PM, Doug Landau wrote: On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote: On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote: On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote: Given that the ducting was manufactured from 0.032" stainless I would have to say that it is exactly the same. Given that "welding" is a process whereby metals are melted and then fused together, with or without additional filler metal, welding the same sort of material using TIG is exactly the same process whether it is 4130 or stainless. If steel, then once the metal is melted than any "temper" is destroyed. In fact it is destroyed long before the metal melts. I'm being a bit pedantic here as welding aluminum, magnesium or titanium can be a bit difference due to the way the metal reacts. Quite to the contrary in my estimation - when you are a good, fast arc welder you only destroy the temper at the spot of the weld and the added material adds additional strength to that location with a softer metal that does not crack or break easily. You are headed in the right direction, but you haven't gotten there yet. Welding of any sort results in the melting of the parent metal which anneals the metal in the weld zone and decreasingly the further away from the weld zone until you reach a point where the temperature isn't high enough to effect the "temper". Contrary to what you say, the actual weld bead is not composed of only the metal added by the welding rod, but is a mixture of the parent metal and the welding rod material. It is quite easy to produce a very brittle weld bead by ignoring this fact. The most common may be using a stainless rod to weld steel. The stainless filler can absorb sufficient carbon from the steel to become extremely hard and brittle. And this is absolutely nothing like arc welding stainless or other metals that are not extreme examples of hardened steel. Brazing properly done to the proper metals does not remove the temper and that is why on the higher quality steel frames they would often use silver solder to braze tube and lug together to lessen the possibility of overheating the tube and destroying the temper. That is just wrong. At least if referring to silver soldering, or silver brazing, as it is now referred to. Heat treating steel is a matter of hardening the steel to its hardest possible state and than reducing this hardness by re-heating to a lower temperature to reduce the hardness. Any high strength silver brazing that I have seen done requires heating the parent metal to at least a dull red temperature which is certainly sufficient to reduce it's hardness. What I think you are talking about is the so called "air hardening" steels that when heated to a certain temperature and cooled simply be being exposed to ambient air temperature will harden to some extent. I might mention that I was making and hardening knives when I was 15 years old and while I didn't understand why heating a knife to a "cherry red" and quenching it in salt water hardened the blade and than re-heating it to a yellowish color tempered it, but I certainly knew how to do it. As for welding I was a certified oxy-acet aircraft welder (steel and aluminum) when I was 20 years old and my last U.S. government certification - TIG welding stainless, aluminum and titanium was done just before I retired from the Air Force. Why salt water? Depending on the alloy of steel used, desired temperature change rate for tempering or hardening, temp masks and so on, the quench may be in water, brine or oil. Generally water quenches faster than oil and salt water quenches faster than water. But depending on the alloy of steel and especially the amount of carbon the steel may become too brittle with faster quenching which is probably why John was talking about tempering. |
#33
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Aluminium or Chromoly frame?
On 11/21/2016 3:39 PM, AMuzi wrote:
On 11/21/2016 12:53 PM, Doug Landau wrote: On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote: On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote: On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote: Given that the ducting was manufactured from 0.032" stainless I would have to say that it is exactly the same. Given that "welding" is a process whereby metals are melted and then fused together, with or without additional filler metal, welding the same sort of material using TIG is exactly the same process whether it is 4130 or stainless. If steel, then once the metal is melted than any "temper" is destroyed. In fact it is destroyed long before the metal melts. I'm being a bit pedantic here as welding aluminum, magnesium or titanium can be a bit difference due to the way the metal reacts. Quite to the contrary in my estimation - when you are a good, fast arc welder you only destroy the temper at the spot of the weld and the added material adds additional strength to that location with a softer metal that does not crack or break easily. You are headed in the right direction, but you haven't gotten there yet. Welding of any sort results in the melting of the parent metal which anneals the metal in the weld zone and decreasingly the further away from the weld zone until you reach a point where the temperature isn't high enough to effect the "temper". Contrary to what you say, the actual weld bead is not composed of only the metal added by the welding rod, but is a mixture of the parent metal and the welding rod material. It is quite easy to produce a very brittle weld bead by ignoring this fact. The most common may be using a stainless rod to weld steel. The stainless filler can absorb sufficient carbon from the steel to become extremely hard and brittle. And this is absolutely nothing like arc welding stainless or other metals that are not extreme examples of hardened steel. Brazing properly done to the proper metals does not remove the temper and that is why on the higher quality steel frames they would often use silver solder to braze tube and lug together to lessen the possibility of overheating the tube and destroying the temper. That is just wrong. At least if referring to silver soldering, or silver brazing, as it is now referred to. Heat treating steel is a matter of hardening the steel to its hardest possible state and than reducing this hardness by re-heating to a lower temperature to reduce the hardness. Any high strength silver brazing that I have seen done requires heating the parent metal to at least a dull red temperature which is certainly sufficient to reduce it's hardness. What I think you are talking about is the so called "air hardening" steels that when heated to a certain temperature and cooled simply be being exposed to ambient air temperature will harden to some extent. I might mention that I was making and hardening knives when I was 15 years old and while I didn't understand why heating a knife to a "cherry red" and quenching it in salt water hardened the blade and than re-heating it to a yellowish color tempered it, but I certainly knew how to do it. As for welding I was a certified oxy-acet aircraft welder (steel and aluminum) when I was 20 years old and my last U.S. government certification - TIG welding stainless, aluminum and titanium was done just before I retired from the Air Force. Why salt water? Depending on the alloy of steel used, desired temperature change rate for tempering or hardening, temp masks and so on, the quench may be in water, brine or oil. Right. Brine gives a faster quench than water. Oil gives a slower quench. Other quench media exist, too. And different alloys of steel may be more "hardenable," which doesn't necessarily mean the stuff has a higher peak hardness; instead, it means the stuff can reach full hardness with a slower quench. Molybdenum and manganese are examples of additions that allow full hardness with a slower quench. A slower quench is sometimes desirable because faster quenches are more likely to cause warping or cracking with complex shapes. -- - Frank Krygowski |
#34
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Aluminium or Chromoly frame?
On Mon, 21 Nov 2016 16:23:46 -0500, Duane
wrote: On 21/11/2016 3:39 PM, AMuzi wrote: On 11/21/2016 12:53 PM, Doug Landau wrote: On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote: On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote: On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote: Given that the ducting was manufactured from 0.032" stainless I would have to say that it is exactly the same. Given that "welding" is a process whereby metals are melted and then fused together, with or without additional filler metal, welding the same sort of material using TIG is exactly the same process whether it is 4130 or stainless. If steel, then once the metal is melted than any "temper" is destroyed. In fact it is destroyed long before the metal melts. I'm being a bit pedantic here as welding aluminum, magnesium or titanium can be a bit difference due to the way the metal reacts. Quite to the contrary in my estimation - when you are a good, fast arc welder you only destroy the temper at the spot of the weld and the added material adds additional strength to that location with a softer metal that does not crack or break easily. You are headed in the right direction, but you haven't gotten there yet. Welding of any sort results in the melting of the parent metal which anneals the metal in the weld zone and decreasingly the further away from the weld zone until you reach a point where the temperature isn't high enough to effect the "temper". Contrary to what you say, the actual weld bead is not composed of only the metal added by the welding rod, but is a mixture of the parent metal and the welding rod material. It is quite easy to produce a very brittle weld bead by ignoring this fact. The most common may be using a stainless rod to weld steel. The stainless filler can absorb sufficient carbon from the steel to become extremely hard and brittle. And this is absolutely nothing like arc welding stainless or other metals that are not extreme examples of hardened steel. Brazing properly done to the proper metals does not remove the temper and that is why on the higher quality steel frames they would often use silver solder to braze tube and lug together to lessen the possibility of overheating the tube and destroying the temper. That is just wrong. At least if referring to silver soldering, or silver brazing, as it is now referred to. Heat treating steel is a matter of hardening the steel to its hardest possible state and than reducing this hardness by re-heating to a lower temperature to reduce the hardness. Any high strength silver brazing that I have seen done requires heating the parent metal to at least a dull red temperature which is certainly sufficient to reduce it's hardness. What I think you are talking about is the so called "air hardening" steels that when heated to a certain temperature and cooled simply be being exposed to ambient air temperature will harden to some extent. I might mention that I was making and hardening knives when I was 15 years old and while I didn't understand why heating a knife to a "cherry red" and quenching it in salt water hardened the blade and than re-heating it to a yellowish color tempered it, but I certainly knew how to do it. As for welding I was a certified oxy-acet aircraft welder (steel and aluminum) when I was 20 years old and my last U.S. government certification - TIG welding stainless, aluminum and titanium was done just before I retired from the Air Force. Why salt water? Depending on the alloy of steel used, desired temperature change rate for tempering or hardening, temp masks and so on, the quench may be in water, brine or oil. Generally water quenches faster than oil and salt water quenches faster than water. But depending on the alloy of steel and especially the amount of carbon the steel may become too brittle with faster quenching which is probably why John was talking about tempering. :-) I once made some drill bushings from "drill steel" that when initially quenched in salt water cracked within seconds of being cooled :-) Sloshed them in the water swished them around to get cool and set them on the bench..... "ping". Sort of emphasizes the book larning that you can get things too hard :-) |
#35
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Aluminium or Chromoly frame?
On Mon, 21 Nov 2016 14:39:39 -0600, AMuzi wrote:
On 11/21/2016 12:53 PM, Doug Landau wrote: On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote: On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote: On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote: Given that the ducting was manufactured from 0.032" stainless I would have to say that it is exactly the same. Given that "welding" is a process whereby metals are melted and then fused together, with or without additional filler metal, welding the same sort of material using TIG is exactly the same process whether it is 4130 or stainless. If steel, then once the metal is melted than any "temper" is destroyed. In fact it is destroyed long before the metal melts. I'm being a bit pedantic here as welding aluminum, magnesium or titanium can be a bit difference due to the way the metal reacts. Quite to the contrary in my estimation - when you are a good, fast arc welder you only destroy the temper at the spot of the weld and the added material adds additional strength to that location with a softer metal that does not crack or break easily. You are headed in the right direction, but you haven't gotten there yet. Welding of any sort results in the melting of the parent metal which anneals the metal in the weld zone and decreasingly the further away from the weld zone until you reach a point where the temperature isn't high enough to effect the "temper". Contrary to what you say, the actual weld bead is not composed of only the metal added by the welding rod, but is a mixture of the parent metal and the welding rod material. It is quite easy to produce a very brittle weld bead by ignoring this fact. The most common may be using a stainless rod to weld steel. The stainless filler can absorb sufficient carbon from the steel to become extremely hard and brittle. And this is absolutely nothing like arc welding stainless or other metals that are not extreme examples of hardened steel. Brazing properly done to the proper metals does not remove the temper and that is why on the higher quality steel frames they would often use silver solder to braze tube and lug together to lessen the possibility of overheating the tube and destroying the temper. That is just wrong. At least if referring to silver soldering, or silver brazing, as it is now referred to. Heat treating steel is a matter of hardening the steel to its hardest possible state and than reducing this hardness by re-heating to a lower temperature to reduce the hardness. Any high strength silver brazing that I have seen done requires heating the parent metal to at least a dull red temperature which is certainly sufficient to reduce it's hardness. What I think you are talking about is the so called "air hardening" steels that when heated to a certain temperature and cooled simply be being exposed to ambient air temperature will harden to some extent. I might mention that I was making and hardening knives when I was 15 years old and while I didn't understand why heating a knife to a "cherry red" and quenching it in salt water hardened the blade and than re-heating it to a yellowish color tempered it, but I certainly knew how to do it. As for welding I was a certified oxy-acet aircraft welder (steel and aluminum) when I was 20 years old and my last U.S. government certification - TIG welding stainless, aluminum and titanium was done just before I retired from the Air Force. Why salt water? Depending on the alloy of steel used, desired temperature change rate for tempering or hardening, temp masks and so on, the quench may be in water, brine or oil. Or the blood of virgins :-( |
#36
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Aluminium or Chromoly frame?
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#37
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Aluminium or Chromoly frame?
On 11/21/2016 7:50 PM, John B Slocomb wrote:
On Mon, 21 Nov 2016 14:39:39 -0600, AMuzi wrote: On 11/21/2016 12:53 PM, Doug Landau wrote: On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote: On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote: On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote: Given that the ducting was manufactured from 0.032" stainless I would have to say that it is exactly the same. Given that "welding" is a process whereby metals are melted and then fused together, with or without additional filler metal, welding the same sort of material using TIG is exactly the same process whether it is 4130 or stainless. If steel, then once the metal is melted than any "temper" is destroyed. In fact it is destroyed long before the metal melts. I'm being a bit pedantic here as welding aluminum, magnesium or titanium can be a bit difference due to the way the metal reacts. Quite to the contrary in my estimation - when you are a good, fast arc welder you only destroy the temper at the spot of the weld and the added material adds additional strength to that location with a softer metal that does not crack or break easily. You are headed in the right direction, but you haven't gotten there yet. Welding of any sort results in the melting of the parent metal which anneals the metal in the weld zone and decreasingly the further away from the weld zone until you reach a point where the temperature isn't high enough to effect the "temper". Contrary to what you say, the actual weld bead is not composed of only the metal added by the welding rod, but is a mixture of the parent metal and the welding rod material. It is quite easy to produce a very brittle weld bead by ignoring this fact. The most common may be using a stainless rod to weld steel. The stainless filler can absorb sufficient carbon from the steel to become extremely hard and brittle. And this is absolutely nothing like arc welding stainless or other metals that are not extreme examples of hardened steel. Brazing properly done to the proper metals does not remove the temper and that is why on the higher quality steel frames they would often use silver solder to braze tube and lug together to lessen the possibility of overheating the tube and destroying the temper. That is just wrong. At least if referring to silver soldering, or silver brazing, as it is now referred to. Heat treating steel is a matter of hardening the steel to its hardest possible state and than reducing this hardness by re-heating to a lower temperature to reduce the hardness. Any high strength silver brazing that I have seen done requires heating the parent metal to at least a dull red temperature which is certainly sufficient to reduce it's hardness. What I think you are talking about is the so called "air hardening" steels that when heated to a certain temperature and cooled simply be being exposed to ambient air temperature will harden to some extent. I might mention that I was making and hardening knives when I was 15 years old and while I didn't understand why heating a knife to a "cherry red" and quenching it in salt water hardened the blade and than re-heating it to a yellowish color tempered it, but I certainly knew how to do it. As for welding I was a certified oxy-acet aircraft welder (steel and aluminum) when I was 20 years old and my last U.S. government certification - TIG welding stainless, aluminum and titanium was done just before I retired from the Air Force. Why salt water? Depending on the alloy of steel used, desired temperature change rate for tempering or hardening, temp masks and so on, the quench may be in water, brine or oil. Or the blood of virgins :-( A savvy armorer would call that a marketing opportunity! -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#38
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Aluminium or Chromoly frame?
On Mon, 21 Nov 2016 20:00:15 -0600, AMuzi wrote:
On 11/21/2016 7:50 PM, John B Slocomb wrote: On Mon, 21 Nov 2016 14:39:39 -0600, AMuzi wrote: On 11/21/2016 12:53 PM, Doug Landau wrote: On Wednesday, November 16, 2016 at 4:16:00 PM UTC-8, John B Slocomb wrote: On Wed, 16 Nov 2016 10:09:14 -0800 (PST), wrote: On Tuesday, November 15, 2016 at 6:09:24 PM UTC-8, John B Slocomb wrote: Given that the ducting was manufactured from 0.032" stainless I would have to say that it is exactly the same. Given that "welding" is a process whereby metals are melted and then fused together, with or without additional filler metal, welding the same sort of material using TIG is exactly the same process whether it is 4130 or stainless. If steel, then once the metal is melted than any "temper" is destroyed. In fact it is destroyed long before the metal melts. I'm being a bit pedantic here as welding aluminum, magnesium or titanium can be a bit difference due to the way the metal reacts. Quite to the contrary in my estimation - when you are a good, fast arc welder you only destroy the temper at the spot of the weld and the added material adds additional strength to that location with a softer metal that does not crack or break easily. You are headed in the right direction, but you haven't gotten there yet. Welding of any sort results in the melting of the parent metal which anneals the metal in the weld zone and decreasingly the further away from the weld zone until you reach a point where the temperature isn't high enough to effect the "temper". Contrary to what you say, the actual weld bead is not composed of only the metal added by the welding rod, but is a mixture of the parent metal and the welding rod material. It is quite easy to produce a very brittle weld bead by ignoring this fact. The most common may be using a stainless rod to weld steel. The stainless filler can absorb sufficient carbon from the steel to become extremely hard and brittle. And this is absolutely nothing like arc welding stainless or other metals that are not extreme examples of hardened steel. Brazing properly done to the proper metals does not remove the temper and that is why on the higher quality steel frames they would often use silver solder to braze tube and lug together to lessen the possibility of overheating the tube and destroying the temper. That is just wrong. At least if referring to silver soldering, or silver brazing, as it is now referred to. Heat treating steel is a matter of hardening the steel to its hardest possible state and than reducing this hardness by re-heating to a lower temperature to reduce the hardness. Any high strength silver brazing that I have seen done requires heating the parent metal to at least a dull red temperature which is certainly sufficient to reduce it's hardness. What I think you are talking about is the so called "air hardening" steels that when heated to a certain temperature and cooled simply be being exposed to ambient air temperature will harden to some extent. I might mention that I was making and hardening knives when I was 15 years old and while I didn't understand why heating a knife to a "cherry red" and quenching it in salt water hardened the blade and than re-heating it to a yellowish color tempered it, but I certainly knew how to do it. As for welding I was a certified oxy-acet aircraft welder (steel and aluminum) when I was 20 years old and my last U.S. government certification - TIG welding stainless, aluminum and titanium was done just before I retired from the Air Force. Why salt water? Depending on the alloy of steel used, desired temperature change rate for tempering or hardening, temp masks and so on, the quench may be in water, brine or oil. Or the blood of virgins :-( A savvy armorer would call that a marketing opportunity! It may be that in today's world the "good stuff" is so rare that some lesser quality stuff has to be used... rather like the Usian political system :-) |
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