|
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject. ?NO specialist is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows will deliberately be vague while explaining the difficulties against which you are up. ? The standard advice to welders who want to weld high strength steels is just don't. ?If steel is heat treated, it implies that there was some objective in heat treating it, such as hardening, and therefore it is at least medium if not high strength. ? That instruction can be qualified to some extent by someone with a higher level of qualification. ? Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel. ?This is used for structures, boilers, etc. and the whole point is that the steel and its weld are ductile. ? To make it hardenable, various alloying elements are added, the most basic of which is carbon. ?This allows the formation of iron carbide, which is very hard. ?To achieve maximum hardness, this requires a very quick quench, so you cannot through harden thick sections. ?To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt, Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur. ?In higher quantities than required to balance the impurities, it leads to extreme work hardening.) ? In the periodic table of elements, Hydrogen is grouped with the metals. ?It is soluble in liquid iron. ?For reasons I don't understand, it doesn't cause so much of a problem in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength. ?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld. ?Each alloying element is given a carbon equivalent, usually less than 1. ?You add all those up in proportion to their % in the composition and add them to the carbon %. ?At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed. ?This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and finally cooling very slowly. ?This is fine if you don't mind losing all the high strength properties as a result of the slow cooling. ?Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way. ? Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence. ?There should be info on t'interweb thingy about carbon equivalents and limits. ? Eddie
?
?
------ Original Message ------
From: ask_derrick@...
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Thank you for the response. I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors. Here is my dilemma, if you can assist, it would be appreciated. For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder. The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench. We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.? Can you assist?
Thanx and Good Shootin'
Derrick Martin
ask_derrick@...
On Saturday, May 18, 2024 at 02:03:05 AM MST, eddie.draper@... via groups.io <eddie.draper@...> wrote:
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject. ?NO specialist is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows will deliberately be vague while explaining the difficulties against which you are up. ? The standard advice to welders who want to weld high strength steels is just don't. ?If steel is heat treated, it implies that there was some objective in heat treating it, such as hardening, and therefore it is at least medium if not high strength. ? That instruction can be qualified to some extent by someone with a higher level of qualification. ? Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel. ?This is used for structures, boilers, etc. and the whole point is that the steel and its weld are ductile. ? To make it hardenable, various alloying elements are added, the most basic of which is carbon. ?This allows the formation of iron carbide, which is very hard. ?To achieve maximum hardness, this requires a very quick quench, so you cannot through harden thick sections. ?To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt, Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur. ?In higher quantities than required to balance the impurities, it leads to extreme work hardening.) ? In the periodic table of elements, Hydrogen is grouped with the metals. ?It is soluble in liquid iron. ?For reasons I don't understand, it doesn't cause so much of a problem in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength. ?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld. ?Each alloying element is given a carbon equivalent, usually less than 1. ?You add all those up in proportion to their % in the composition and add them to the carbon %. ?At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed. ?This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and finally cooling very slowly. ?This is fine if you don't mind losing all the high strength properties as a result of the slow cooling. ?Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way. ? Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence. ?There should be info on t'interweb thingy about carbon equivalents and limits. ? Eddie
?
?
------ Original Message ------
From: ask_derrick@...
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Derrick if ya have not already asked over here on the Practical
Machinist gunsmith portion of the forum Your question should
garner some good info . Free to join & there's? at least a
couple? thousand years of experience there .
good luck
animal
On 5/18/24 8:24 AM, Retired Gunsmith
via groups.io wrote:
toggle quoted message
Show quoted text
Thank you for the response.
I am mildly familiar with
what you discussed on how steels are hardened and the perils
of Hydrogen contamination , thru other projects and
advisors.
Here is my dilemma, if you
can assist, it would be appreciated.
For about 30 years, I have
been working on M-1 and M1A rifles. One of the tasks is to
weld a recoil lug onto the rear of the receiver. I had a
certified welder and he developed the process with the
assistance of? the Metallurgy Department at his day job. He
commented on the process several times, but I never wrote it
down. He died suddenly, and I am now trying to
remember/recreate the process to work with a new welder.
The receivers are
carburized 8620, the lugs are 1018, rod is Linde 65, this I
know. My memory of the procedure is to tack the lug in two
corners, preheat to 800degF, weld the lug in one pass on
each side and then water quench. We had done several hundred
receivers, without any failures and I know the process
worked. Mostly, I am looking for validation that I remember
the process correctly.?
Can you assist?
I've
noted that there is a deafening silence from
qualified metallurgists, so as a chartered
mechanical engineer, I'll advise what little I
know on this subject. ?NO specialist is going to
proffer free advice or any advice that allows you
to proceed safely without a.) knowledge of what
the steel consists of, b.) the application,
including stresses, safety implications etc. and
c.) professional indemnity insurance, so what
follows will deliberately be vague while
explaining the difficulties against which you are
up.
?
The
standard advice to welders who want to weld high
strength steels is just don't. ?If steel is heat
treated, it implies that there was some objective
in heat treating it, such as hardening, and
therefore it is at least medium if not high
strength.
?
That
instruction can be qualified to some extent by
someone with a higher level of qualification.
?
Steel
that is nominally not hardenable by heat treatment
is close to pure iron and is referred to as mild
steel. ?This is used for structures, boilers, etc.
and the whole point is that the steel and its weld
are ductile.
?
To
make it hardenable, various alloying elements are
added, the most basic of which is carbon. ?This
allows the formation of iron carbide, which is
very hard. ?To achieve maximum hardness, this
requires a very quick quench, so you cannot
through harden thick sections. ?To slow down the
quench requirements and allow thicker sections to
be through hardened various other alloying
elements can be added, such as Chromium, Vanadium,
Cobalt, Nickel, Manganese etc. ?(Manganese is in
virtually all steel anyway, just as a means of
mopping up impurities like Phosphorous and
Sulphur. ?In higher quantities than required to
balance the impurities, it leads to extreme work
hardening.)
?
In
the periodic table of elements, Hydrogen is
grouped with the metals. ?It is soluble in liquid
iron. ?For reasons I don't understand, it doesn't
cause so much of a problem in thin mild steel, but
in hardenable steel, or even thick mild steel, it
comes out of solution during the solidification
process and congregates at the grain boundaries,
so the grains are not stuck together as well,
thereby causing gross lack of strength. ?There is
a limit to the % carbon in the steel beyond which
you just cannot successfully weld. ?Each alloying
element is given a carbon equivalent, usually less
than 1. ?You add all those up in proportion to
their % in the composition and add them to the
carbon %. ?At a lower figure than the limit,
welding can be successful but only if a suitable
procedure is devised and followed. ?This typically
includes the exclusion of hydrogen (moisture,
which is why rods are baked for extensive
periods), preheating the job for a period to a
specified temperature, maintaining a certain
minimum temperature during the welding,
maintaining a specified temperature for a
significant period after the welding to allow the
hydrogen to diffuse out of the job, which it does
only slowly, and finally cooling very slowly.
?This is fine if you don't mind losing all the
high strength properties as a result of the slow
cooling. ?Never gone further than this myself, but
it may then be possible to reharden the whole job
in the normal way.
?
Very
sorry, but I feel you're going to have to pay a
pro for a procedure if the job is critical, or try
some of the above and test it if a few failures
are of little consequence. ?There should be info
on t'interweb thingy about carbon equivalents and
limits.
?
Eddie
?
?
------ Original Message ------
From: ask_derrick@...
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a
Degreed Metallurgist?
I am working on a project and need some advice on
welding heat treated materials.
Ask_derrick@...
|
I think the water quench is problematic, you don't want to create stress. Usually when you do a preheat to weld, you also do a post heat to slow down the cool down.
It's probably to prevent heat migration towards the locking surfaces.
It could be stainless steel rod like 312 or a specialty maintenance rod.
Plenty is unknown, could be high heat input, fast bead? to keep heat input down.
On Sat, May 18, 2024 at 11:24?AM Retired Gunsmith via <ask_derrick= [email protected]> wrote: Thank you for the response. I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors. Here is my dilemma, if you can assist, it would be appreciated. For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder. The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench. We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.? Can you assist?
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject.? NO specialist is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows will deliberately be vague while explaining the difficulties against which you are up. ? The standard advice to welders who want to weld high strength steels is just don't.? If steel is heat treated, it implies that there was some objective in heat treating it, such as hardening, and therefore it is at least medium if not high strength. ? That instruction can be qualified to some extent by someone with a higher level of qualification. ? Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel.? This is used for structures, boilers, etc. and the whole point is that the steel and its weld are ductile. ? To make it hardenable, various alloying elements are added, the most basic of which is carbon.? This allows the formation of iron carbide, which is very hard.? To achieve maximum hardness, this requires a very quick quench, so you cannot through harden thick sections.? To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt, Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur.? In higher quantities than required to balance the impurities, it leads to extreme work hardening.) ? In the periodic table of elements, Hydrogen is grouped with the metals.? It is soluble in liquid iron.? For reasons I don't understand, it doesn't cause so much of a problem in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength.? There is a limit to the % carbon in the steel beyond which you just cannot successfully weld.? Each alloying element is given a carbon equivalent, usually less than 1.? You add all those up in proportion to their % in the composition and add them to the carbon %.? At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed.? This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and finally cooling very slowly.? This is fine if you don't mind losing all the high strength properties as a result of the slow cooling.? Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way. ? Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence.? There should be info on t'interweb thingy about carbon equivalents and limits. ? Eddie
?
? ------ Original Message ------
From: ask_derrick=[email protected]
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Derrick
You have me curious. I have been shooting M1's for many years and never heard of this procedure.
What is the reasoning behind it?
Could you post a picture of what you are doing to the recievers?
Thanks
Erik A
toggle quoted message
Show quoted text
Thank you for the response.
I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors.
Here is my dilemma, if you can assist, it would be appreciated.
For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy
Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder.
The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench.
We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.?
Can you assist?
Thanx and Good Shootin'
Derrick Martin
ask_derrick@...
On Saturday, May 18, 2024 at 02:03:05 AM MST, eddie.draper@... via groups.io <eddie.draper@...> wrote:
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject. ?NO specialist
is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows
will deliberately be vague while explaining the difficulties against which you are up.
?
The standard advice to welders who want to weld high strength steels is just don't. ?If steel is heat treated, it implies that there was some objective in heat treating it,
such as hardening, and therefore it is at least medium if not high strength.
?
That instruction can be qualified to some extent by someone with a higher level of qualification.
?
Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel. ?This is used for structures, boilers, etc. and the whole point
is that the steel and its weld are ductile.
?
To make it hardenable, various alloying elements are added, the most basic of which is carbon. ?This allows the formation of iron carbide, which is very hard. ?To achieve maximum
hardness, this requires a very quick quench, so you cannot through harden thick sections. ?To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt,
Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur. ?In higher quantities than required to balance the impurities, it leads to extreme work hardening.)
?
In the periodic table of elements, Hydrogen is grouped with the metals. ?It is soluble in liquid iron. ?For reasons I don't understand, it doesn't cause so much of a problem
in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength.
?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld. ?Each alloying element is given a carbon equivalent, usually less than 1. ?You add all those up in proportion to their % in the composition and add them to the carbon
%. ?At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed. ?This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for
a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and
finally cooling very slowly. ?This is fine if you don't mind losing all the high strength properties as a result of the slow cooling. ?Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way.
?
Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence.
?There should be info on t'interweb thingy about carbon equivalents and limits.
?
Eddie
?
?
------ Original Message ------
From: ask_derrick@...
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Me too.? I have a couple destined for conversion into BM-59s.? That will involve milling on the receiver.?
I also have a couple of receiver forgings that might at some point ask to be finished.
Derrick
You have me curious. I have been shooting M1's for many years and never heard of this procedure.
What is the reasoning behind it?
Could you post a picture of what you are doing to the recievers?
Thanks
Erik A
Thank you for the response.
I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors.
Here is my dilemma, if you can assist, it would be appreciated.
For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy
Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder.
The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench.
We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.?
Can you assist?
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject.? NO specialist
is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows
will deliberately be vague while explaining the difficulties against which you are up.
?
The standard advice to welders who want to weld high strength steels is just don't.? If steel is heat treated, it implies that there was some objective in heat treating it,
such as hardening, and therefore it is at least medium if not high strength.
?
That instruction can be qualified to some extent by someone with a higher level of qualification.
?
Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel.? This is used for structures, boilers, etc. and the whole point
is that the steel and its weld are ductile.
?
To make it hardenable, various alloying elements are added, the most basic of which is carbon.? This allows the formation of iron carbide, which is very hard.? To achieve maximum
hardness, this requires a very quick quench, so you cannot through harden thick sections.? To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt,
Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur.? In higher quantities than required to balance the impurities, it leads to extreme work hardening.)
?
In the periodic table of elements, Hydrogen is grouped with the metals.? It is soluble in liquid iron.? For reasons I don't understand, it doesn't cause so much of a problem
in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength.
?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld.? Each alloying element is given a carbon equivalent, usually less than 1.? You add all those up in proportion to their % in the composition and add them to the carbon
%.? At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed.? This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for
a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and
finally cooling very slowly.? This is fine if you don't mind losing all the high strength properties as a result of the slow cooling.? Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way.
?
Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence.
?There should be info on t'interweb thingy about carbon equivalents and limits.
?
Eddie
?
?
------ Original Message ------
From: ask_derrick=[email protected]
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
|
Springfield and LRB both offer lugged receivers. You can see them on their websites. I will gladly post photos of a welded receiver, if you want to see it. Lugging was started in the mid? eighties to prolong the bedding. With a lugged receiver, the bedding was good for the life of the barrel. Otherwise, (in a serious competition rifle), the bedding would need to be redone at least once a year.? I shot for the All National Guard Team from 1988 to 2003. At that time, each of the 3 major teams had different philosophies about lugging and bedding. The US Army? Marksmanship Unit at Ft. Benning, did not believe in lugging, they physically glued the receiver into the stock. The All National Guard Marksmanship Unit at Nashville and later Little Rock, used rear lugs and release agent when bedding. The Marine Corps Weapon Training Battalion at Quantico used double lugs ( one at front and rear) and release agent when bedding. We all went to the same matches (i.e. Interservice, Camp Perry, etc.) and no one knew who was going to win, so from my view, all philosophies are valid. For civilian competitors lugging was preferred, so they would not have the expense of rebedding each year.?
Thanx and Good Shootin'
Derrick Martin
ask_derrick@...
On Saturday, May 18, 2024 at 03:59:57 PM MST, Nick Andrews <nickjandrews@...> wrote:
Me too.? I have a couple destined for conversion into BM-59s.? That will involve milling on the receiver.?
I also have a couple of receiver forgings that might at some point ask to be finished.
Derrick
You have me curious. I have been shooting M1's for many years and never heard of this procedure.
What is the reasoning behind it?
Could you post a picture of what you are doing to the recievers?
Thanks
Erik A
Thank you for the response.
I am mildly familiar with what you discussed on how steels are hardened and the perils of Hydrogen contamination , thru other projects and advisors.
Here is my dilemma, if you can assist, it would be appreciated.
For about 30 years, I have been working on M-1 and M1A rifles. One of the tasks is to weld a recoil lug onto the rear of the receiver. I had a certified welder and he developed the process with the assistance of? the Metallurgy
Department at his day job. He commented on the process several times, but I never wrote it down. He died suddenly, and I am now trying to remember/recreate the process to work with a new welder.
The receivers are carburized 8620, the lugs are 1018, rod is Linde 65, this I know. My memory of the procedure is to tack the lug in two corners, preheat to 800degF, weld the lug in one pass on each side and then water quench.
We had done several hundred receivers, without any failures and I know the process worked. Mostly, I am looking for validation that I remember the process correctly.?
Can you assist?
I've noted that there is a deafening silence from qualified metallurgists, so as a chartered mechanical engineer, I'll advise what little I know on this subject.? NO specialist
is going to proffer free advice or any advice that allows you to proceed safely without a.) knowledge of what the steel consists of, b.) the application, including stresses, safety implications etc. and c.) professional indemnity insurance, so what follows
will deliberately be vague while explaining the difficulties against which you are up.
?
The standard advice to welders who want to weld high strength steels is just don't.? If steel is heat treated, it implies that there was some objective in heat treating it,
such as hardening, and therefore it is at least medium if not high strength.
?
That instruction can be qualified to some extent by someone with a higher level of qualification.
?
Steel that is nominally not hardenable by heat treatment is close to pure iron and is referred to as mild steel.? This is used for structures, boilers, etc. and the whole point
is that the steel and its weld are ductile.
?
To make it hardenable, various alloying elements are added, the most basic of which is carbon.? This allows the formation of iron carbide, which is very hard.? To achieve maximum
hardness, this requires a very quick quench, so you cannot through harden thick sections.? To slow down the quench requirements and allow thicker sections to be through hardened various other alloying elements can be added, such as Chromium, Vanadium, Cobalt,
Nickel, Manganese etc. ?(Manganese is in virtually all steel anyway, just as a means of mopping up impurities like Phosphorous and Sulphur.? In higher quantities than required to balance the impurities, it leads to extreme work hardening.)
?
In the periodic table of elements, Hydrogen is grouped with the metals.? It is soluble in liquid iron.? For reasons I don't understand, it doesn't cause so much of a problem
in thin mild steel, but in hardenable steel, or even thick mild steel, it comes out of solution during the solidification process and congregates at the grain boundaries, so the grains are not stuck together as well, thereby causing gross lack of strength.
?There is a limit to the % carbon in the steel beyond which you just cannot successfully weld.? Each alloying element is given a carbon equivalent, usually less than 1.? You add all those up in proportion to their % in the composition and add them to the carbon
%.? At a lower figure than the limit, welding can be successful but only if a suitable procedure is devised and followed.? This typically includes the exclusion of hydrogen (moisture, which is why rods are baked for extensive periods), preheating the job for
a period to a specified temperature, maintaining a certain minimum temperature during the welding, maintaining a specified temperature for a significant period after the welding to allow the hydrogen to diffuse out of the job, which it does only slowly, and
finally cooling very slowly.? This is fine if you don't mind losing all the high strength properties as a result of the slow cooling.? Never gone further than this myself, but it may then be possible to reharden the whole job in the normal way.
?
Very sorry, but I feel you're going to have to pay a pro for a procedure if the job is critical, or try some of the above and test it if a few failures are of little consequence.
?There should be info on t'interweb thingy about carbon equivalents and limits.
?
Eddie
?
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------ Original Message ------
From: ask_derrick=[email protected]
To: [email protected]
Sent: Wednesday, May 15th 2024, 19:25
Subject: [SouthBendLathe] Anyone in the Group a Degreed Metallurgist?
I am working on a project and need some advice on welding heat treated materials.
Ask_derrick@...
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Nick Andrews