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Forged???

Discussion in 'Rifle Country' started by TimH, Apr 30, 2003.

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  1. Stinkyshoe

    Stinkyshoe Member

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    Shear_Stress

    This I heard from a very credible member of the American Pistol Smiths Guild. I assume he'd know.

    Ss
     
  2. harrydog

    harrydog Member

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    Ash,
    I think you're the one who brought up the longevity issue in that forged parts wore out more quickly based on what happens in a race car engine. I was merely pointing that forged cranks are also used in many production road cars where longevity is important.
    My original point was that forged parts, cranks and connecting rods in particular, are generally stronger than their cast counterparts and that is why they are used. In many racing applications a cast crank would end up cracking under the high stress.
    The only real advantage of cast parts over forged or machined from bar stock parts is the manufacturing cost.

    Slamfire,
    Some of those big diesel engines may have cast cranks but they are very low RPM engines.
    It's high RPM that really stresses a crankshaft. But even so, I did a search and it appears that many diesel engines including Cummins and Caterpillar are using forged steel cranks.
     
  3. Slamfire

    Slamfire Member

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    I can believe that. I would love to have seen a forging press large enough to stamp out some of the cast iron cranks I saw. They were huge. And those engines, they are designed to run 1500 rpm for forever. Not to say the loads don't vary, but they are not high rpm.

    If you want to see the world's largest diesel, take a look at the pictures on this site.

    http://people.bath.ac.uk/ccsshb/12cyl/
     
  4. harrydog

    harrydog Member

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    Holy crap! Now that's a huge engine. At 1660 gallons of fuel per hour, imagine how much fuel it has to carry to cross the Pacific or Atlantic!
     
  5. Ash

    Ash Member

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    "I think you're the one who brought up the longevity issue in that forged parts wore out more quickly based on what happens in a race car engine."

    No, I actually did not. My point merely was that using a race car is not a good example of longevity or superiority of forged parts. Indeed, I said “They (race car parts) are wonderfully strong and capable for short-term use, but they are worn out very quickly. Of course, a cast part might just wear sooner."

    The point is, race cars are bad examples for any kind of longevity comparisons, whether they be tires, engine oil, or metals.

    Ash
     
  6. daniel (australia)

    daniel (australia) Member

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    In relation to crankshafts and rods I said this back at post #58 in this thread

    Generally cranks and rods aren't running at stresses anywhere near their maximum strength, unless something goes seriously wrong. Nor do they wear much, even in race engines, unless bearings and/or lubrication are inadequate. The main thing that will bring their service life to an end, often in the form of an expensive unplanned reorganisation of the engine design, is fatigue. Fatigue is where a crack gets a start, perhaps in a sharp corner or defect, and under the enormous number of load cycles these components undergo it gradually progresses acoss the section, until there's not enough left to support the load and the whole thing lets go in a cloud of oily smoke and swearing.

    Now fatigue life depends on a number of factors, including the material chosen, how well it is radiused, peened etc to minimise or eliminate possible crack initiation sites, and the applied stress. Now of course a race engine crank runs at fairly high stress, especially as it will generally be specced to be fairly light, but you can also reduce the stresses by good balancing and a few other tricks. Frequent tearing down and inspection including crack testing also helps you to keep an eye on things, and (ideally) swap out components before fatigue cracks can do damage.

    In the case of the big diesel it has a massive crank running comparatively slowly, so fatigue is much less a factor. It probably also has pretty massive conrods too, and fairly low piston velocity, as well as running at a fairly constant speed without sudden accelerations. The net effect is that the big diesel can well get away with a nodular iron crank (one of a size which would be exceptionally difficult to produce by forging too), and very long maintenance intervals/service life.

    In the case of the race car, even if the rules didn't specify it, the steel crank would be better than the iron largely because the steel is better able to resist fatigue. There are potentially even better materials too, though for F1 at least steel is mandatory.

    Point is though, that all of this is entirely irrelevant to the use of investment cast components in firearms. No one is talking about making a receiver from nodular or SG iron, just for starters. More importantly though fatigue resistance is just not a factor in the case of sporting firearms. As I said a couple of weeks ago

    In any design, you have to look at the properties the material needs to have for that application, not how well suited it is to some other, entirely different application.
     
  7. harrydog

    harrydog Member

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    Caspian sells excellent cast steel 1911 receivers. They have proven to be every bit as durable as forged or bar stock receivers and carry a lifetime warranty against cracking. However, for their slides they use forged steel because a cast slide would not last nearly as long. Slides endure greater stress and impact than receivers.
    Cast parts may be perfectly fine for many applications but they are almost always specified only because they cost less to manufacture, not because they are better.
     
  8. Boston T. Party

    Boston T. Party Member

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    That seems an excellent and accurate encapsulation of the issue, thanks.

    Regarding McClung's contribution to my book Safari Dreams, it was
    in context of cast steel receivers in dangerous game rifles. For such
    a gun, you want every possible odd in your favor, such as controlled-feed,
    M98 extractor, fixed ejector, ample caliber, etc. I still agree with McClung
    that a forged-steel receiver adds to your odds, and that a cast steel
    receiver does not (and possibly lowers your odds).

    If you don't have to take an unnecessary chance, why do it when a
    forged Win M70 or CZ550 Magnum is available for the same price?

    Regarding daniel's contention that 4140 steel has a sufficiently low
    carbon content to avoid the dendrite paths from the casting process,
    I'm sure McClung will respond to that when he has a moment.

    Thanks to all so far for your comments.
    I'm always up for learning something, or correcting my own misinformation.

    btw, my book Safari Dreams is in, and turned out very nicely.
    If you're keen to hunt in Africa, it will be a great use to you.

    $36 cash gets you a signed postpaid copy.
    352 pages, 100 color photos

    Javelin Press
    POB 31
    Ignacio, Co. 81137-0031

    Regards,
    Boston
     
  9. Boston T. Party

    Boston T. Party Member

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    Kevin McClung's reply

    Quoted below in full is McClung's email.

    Boston



     
  10. JohnKSa

    JohnKSa Member

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    Cheap shot.

    Posting an email from someone else that insults a member on THR when you can't do it yourself per the forum rules.
    This is why Rugers are known for breaking... :rolleyes:
    Naturally, anyone who disagrees with the esteemed Mr. McClung must be doing so out of emotion or personal interest. Apparently he finds it unfathomable that there could be a disgreement based on any thing technical. :rolleyes:
     
  11. Slamfire

    Slamfire Member

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    Scandal mongering employees seldom have nice words to say about their employer. In fact, with a little prompting you can get from any employee of any business a long litany of why things are messed up at work.

    And the fact there is a pile of rejects means a least there is a QA process, maybe not to the satisfaction of disgruntled former employees.

    As to the complaints; yes, overall the earth is messed up and the country is going down a rat hole, but what specifically are the incidents that they are complaining about? Dollar coffee machines?, not enough parking spaces at work?, etc? I have heard any number of employees dog the products that their employer makes, and yet I have never heard any employee admit that they personally, with malice and forethought, sent out product that was dangerous or defective.

    Disgrunted employees find out later they had it good when their jobs are off shored.
     
  12. harrydog

    harrydog Member

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    This thread has taken a turn for the worse which I don't really want to get caught up in, but I do have a question regarding Ruger castings.
    My question is, are Rugers really known for breaking? I thought it was just the opposite. I know that Caspian has never had a 1911 receiver returned to them due to cracking or breaking, and they are cast by Ruger. Also Ruger revolvers and rifles are known for being extremely strong and durable. More so than some of their competition. So I'm wondering where the "known for breaking" comes from.
    By the way, I don't own or never have owned a Ruger, so I really don't have a vested interest in this at all.
     
  13. daniel (australia)

    daniel (australia) Member

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    Well, yeah, whatever…:rolleyes:

    I have to laugh though, especially at this bit:

    I have no financial or personal stake in this argument at all. Sure, I did write an Honours thesis on the production of high integrity castings, and I did spend a bit of time in researching, testing and developing this sort of stuff for defence and other applications, but that was a fair while ago. I spent rather more time as a metallurgical consultant, mainly investigating failures, and I’ve seen them in all sorts of products, so I don’t think I’m “emotionally invested” in any particular production method either. I’ve moved on even from there though, and my interest in all of this is in the “science thing”, and nothing else.

    I note with some amusement though that Mr McClung in fact does have a financial stake in forged receivers, given that they are sold by his company – as of course does the fellow who chose him to provide “technical” input to a book he keeps mentioning.

    The “science thing” too, I had to smile a wry smile at that. :p

    For starters:

    McClung claimed earlier that you’d get dendrites of carbide, so assume that is what he is talking about here.

    The credibility gap is yawning wider though: with the steels we’re talking about it doesn’t actually happen that way at all. This is all fairly basic metallurgy, and there are vast atlases of diagrams based on enormous amounts of empirical data showing precisely what does happen with different alloys as they solidify slowly (phase equilibrium diagrams) and as they are cooled at varying rates from slow furnace cooling to rapid quenching (TTT diagrams). With a medium carbon (“hypoeutectoid”) steel such as you might use for a receiver, cooled slowly from liquid, the steel doesn’t solidify all at once, but in fact the first thing to solidify is the ferrite, not the carbide. Ferrite is essentially pure iron (with a very small amount of dissolved carbon). Carbon is concentrated in the remaining liquid until it reaches about 0.8%, and this solidifies as a phase called pearlite, consisting of laminations of carbide and ferrite. You’ll see the resulting microstructure in cast steel and you’ll also see it in annealed forged steel of the same composition.

    What about dendrites though? Well, by and large metals solidify by forming dendrites. Steel is one of them. Dendrites are no more than the name for what you see in the development of the crystal structure from the liquid as the metal cools, as a sort of branching framework which grows until the whole structure is solidified
    [​IMG]
    You see the same type of crystallisation at work in snowflakes. Saying you'd prevent the formation of dendrites as you make steel is a bit like saying you can prevent a tree from containing wood. Moreeover, as I’ve said, the ferrite actually forms first in the steels we’re talking about, not the carbide, so the dendrites from which the crystals start to grow consist of this ferrite.

    As for "cooling related" issues, you get these with forgings too. Quench cracking for example, or distortion, or wrong hardness. All of these are "cooling related". You avoid them with good process control, and the same applies to castings.

    You’ll always have some scrap, with any casting process, mainly in the form of sprues, risers etc. You’ll get rejects too, for any number of reasons. Same with any process. It says nothing of the comparative merits of the product, and I suspect is being grossly exaggerated here.

    In foundry practice you simply recycle the metal back into the furnace. As to segregation according to alloy again I’d be surprised if Ruger wasn’t doing this, as it is standard practice in any foundry I've been in, but in any case it is also standard practice to analyse each heat immediately before pouring and make any adjustments to bring it to spec. I’ve done this myself, many times (though a long time ago): it takes a matter of minutes to carry out a spectrographic analysis and calculate the alloy additions to bring an off-spec. heat to spec again, before you pour.

    As for disgruntled employees well, I take such hearsay with a substantial grain of salt. It wouldn’t prove anything about the relative merits of forging and casting anyway. In any case it is no secret that there’s been a significant shake up at Ruger's factory over the past year or so. They sought to reduce inventory significantly and it exposed problems in their manufacturing systems which they've had to bite the bullet and address. That has nothing to do with the relative merits of forging and casting either.

    I don’t place all that much credence in one firearm supplier running down another’s product either, but that is all I see here. Where's the "science"?





    .
     
  14. Slamfire

    Slamfire Member

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    Daniel: Knock em dead mate:

    We all know that vendors always fairly rate the products of their competitors. :rolleyes: Rubbish!

    All I read from the critics of casting is unsubstantiated mud slinging. Almost at their last stand. The final stand will be that they don't like casting because they don't like the people who make castings.

    These guys trust their lives daily on the cheapest cast components in one of the deadliest games around: Cars. Like 50,000 US citizens die per year and there are 600,000 vehicle injuries.!!

    But what they emphasize is a cast receiver failing during a what, a maybe once in the lifetime hunt against lions and tigers and bears!
     
  15. JohnKSa

    JohnKSa Member

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    The little "eye-rolling smiley= :rolleyes:" is indicative of sarcasm. ;)

    You are correct. In spite of all the innuendo about QA issues and casting problems from our "expert", Rugers have a well-deserved reputation for extreme durability.
    Agree, the email is several paragraphs of attacks and innuendo with maybe a couple of sentences of technical information (being generous).

    I'm always terribly unimpressed with people who claim to be experts but when pressed choose to resort to pomposity, innuendo, and insults rather than responding technically.
     
  16. Boston T. Party

    Boston T. Party Member

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    I understand the point, but didn't consider "smugly pedantic"
    to have crossed the line of insulting. It certainly wasn't my
    intention to insult or facilitate such. From here on, I'll post
    only what I have to say.


    from Daniel:

    Actually, I've no financial stake in any forged steel product.
    I wrote a book containing the opinions of myself and others.
    I've never found any reason to doubt Kevin's technical
    expertise in my 16 years of knowing him. He exposure of the
    Zylon material failure in bullet-resistant vests points to his
    wide understanding of material properties.

    Before I published Kevin's essay on the subject, I searched
    diligently for facts and discussion on the forged vs. cast issue,
    but this thread did not come up. (I found it only post-publication
    when I was running down whether or not Montana rifles were
    cast, and posted on it that same day.)

    Kevin, to my knowledge, has nothing personal against Ruger
    that would color his stance against cast steel receivers.


    _____________
    Regarding the veracity of Ruger's former employees, I cannot
    comment to that with any knowledge, though I take the point
    that some may be bitter and have an agenda.


    _____________
    from Daniel:
    Is it your contention that cast receivers of “hypoeutectoid” steel
    are slowly cooled?

    If, however, they are cooled fast, does that tend to collect
    carbides in a fern-like lattice vs. randomly distributing them?



    _____________
    In order to constrain this thread within technical bounds,
    I pose the following question:

    Assuming two bolt-action receivers of identical dimensions and
    weight -- one constructed in forged steel and other in cast steel
    (both of the best steel, process, and QC) -- would anybody here
    assert that the cast version is of equal or superior tensile strength?


    (Interestingly on this very point are two virtually identical rifle
    receivers: the forged Win M70 Classic and Montana's cast version
    of it. The Montana action may be heavier, however.)

    Thank you all for your posts.
    My only reason for posting is to further understanding of this issue.
    May true science win.

    Boston

     
  17. JesseL

    JesseL Member

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    I would assert that until they do some serious real-world testing and analysis of both receivers, nobody is qualified to state definitively which receiver is stronger. No science exists in a vacuum (except maybe pure mathematics).
     
  18. Boston T. Party

    Boston T. Party Member

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    Surely a test of two otherwise identical steel cavity forms
    has been done to ascertain the strength of casting vs. forged.
    If so, where?

    Remember, my question is not whether a cast receiver can be
    sufficiently oversized to equal the strength of a (thinner) forged
    receiver, but, rather, the comparative strength of equal weight
    and thickness of the two.

    Boston
     
  19. hubel458

    hubel458 Member

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    A false premise-It should be stated how much thicker forged
    reciever has to be to match investment one.

    Don't do no good badmouth investment cast, heat treated stuff .
    I have stressed tested the Ruger 77, and emphatically
    state that they are stronger than the forged Win 70.
    And the Win 70 and many others are thicker at the side of
    reciever ring in same place as the flat side of the Ruger 77, where
    the 77 is thinnest where if it was going to split, that's the place.
    I overloaded, not by plan, a 77 in 458, so bad it bulged chamber ahead
    of the reciever about ..060, flowed the brass case around bolt,
    but it didn't blow out the corners of the case, or shear the lugs
    or shear the lug seats. Took out barrel with lathe, tested action, put
    in other barrel still going after another thousand rounds, I know that
    the Win wouldn't of held. The investment casting can be treated to higher
    strength than forged. Can be treated more uniformly throughout
    thus giving a much higher strength all through the material.
    They both have same diameter barrel thread
    but the Win is about .025" bigger OD than Ruger on the sides, and
    the Win wouldn't have held like the Ruger. Ed
     
  20. Slamfire

    Slamfire Member

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    I agree. I can recall reading something in the 70's where Ruger shear tested the lugs on their bolts and found they took twice the shear of forged bolts. But, if memory was right, the forged bolts were like M1903 bolts. The material technology and process technology was decades different, so it was not an apples to apples comparison. The tests were not published in the open literature.

    But I want to say, at some point the tensile and ultimate of the receiver becomes meaningless. Steel is far stronger than brass. At some pressure point the cartridge ruptures. I personally think action strength is really a measure of how well the action design supports the cartridge case. If the action properly supports the case, than a plain carbon steel action, like the M38 Japanese, will prevent cartridge rupture far better than the more massive M1917. Which was made of nickel steel. P.O Ackleys’ tests show this.

    Once the cartridge ruptures, the next issue is how well the action protects the user in what is, essentially, a destructive incident.

    I don’t think anyone ever designed an action with the idea that after a “catastrophic” failure, that all the user had to do was screw on a new, intact barrel. It is just good fortune that some have useable receivers after such events. If I were the designer, I would consider the safety margin of the action to have been used up. If these were not individuals, but were rather companies or Armies, I have no doubt that even though the receiver was still intact, it would have been scrapped. Individuals don’t have such deep pockets so ……..

    In the book "Technical Notes" from Armalite, the load of a 30-06 on the bolt face is between 4000 and 6,600 pounds, for a couple of milliseconds. I will bet the wheel bearings on my truck experience more than that on some big pot holes.

    I think the focus on cast versus forged is a distraction, created by corporate advertising, from what is the real issue: Good action design.

    And for that, go read Stuart Otteson’s books on “The Bolt Action”. Good action design is far more complicated than material choice.
     
  21. hubel458

    hubel458 Member

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    Thr reciever besides being intact was also tested.
    No weaknesses showed up. Total loads fired through it
    is about 2000, half before the overload and half after.
    Proper investment, alloyed and treated steel isn't going to
    stress away so to speak, unless you subject it to many
    tens of thousands of pressure cycles, may take hundreds
    of thousands. Now it may fail in a few hundred of my stupid
    overloads, but that would be awful expensive for barrels to
    find out.Ed
     
  22. Boston T. Party

    Boston T. Party Member

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    from Daniel:
    You contend that steel alloy with <0.83% carbon does not form
    carbides because up to 0.83% carbon is dissolved in the
    austenite (gamma iron in liquid phase).

    This is a partial truth.

    Hypoeutectoid alloys contain less carbon content than the maximum
    dissolvable in the parent material of austenite. (The introduction of carbon
    into austenite lowers its temperature of stability, but that effect peaks
    at about 0.83% carbon content.)

    Such alloys with <0.83% carbon will indeed form carbides, though only with
    ferrite (called cementite, or Fe3C) because the austenite first dissolves carbons
    until its saturation point of 0.83%. Cementite plus ferrite -- and slowly cooled --
    is what creates the phase of pearlite (+ free ferrite), beginning at 0.20% carbon.
    Beyond 0.83% carbon, you get free ferrite, pearlite, and non-ferrite carbides
    (i.e., with the other alloys such as vanadium, tungsten, etc.).

    No gun manufacturer wants pearlitic steel because the very definition
    of pearlite means that the once-dissolved-in-austenite carbons were
    foolishly allowed to precipitate out of the austenite solution to form
    segregated cementites (Fe3C). The whole point of a rapid cooling of
    AISI 4140 gun receiver steel (which is oil quenched for 30 minutes from
    an initial temp of some 1525°F/1625°F, by the way, not "slowly cooled"
    as in your model) is to trap individual carbon atoms within the austenite
    crystals, creating tough martensitic steel.

    http://info.lu.farmingdale.edu/depts/met/met205/tttdiagram.html

    (If you quench too slowly, you end up with a phase between pearlite and
    martensite called bainite, but that's a matter irrelevant to our discussion.)

    Yes, quench stresses can form from the formation of martensite, but that
    is why such are relieved through subsequent tempering.

    The fact that gun receiver steels such as AISI 4140 are <0.83%/hypoeutectoid
    alloys is really immaterial regarding the issue of carbides segregating into
    dendrites. By definition, steel is iron with at least 0.20% carbon, else the
    iron could not be formed into martensite (i.e., hardened). And even such
    a low carbon content of 0.20% will precipitate out if the austenite
    were allowed to be "slowly cooled" as per your example.

    I am trying to imagine further your point, to wit, that 4140 cast steel's
    carbon will necessarily form into pearlite cementite layers vs. dendrites,
    but that is not a given at all. Such in part must assume not only a forged
    steel quality of alloy distribution, but also no internally disparate cooling
    (i.e., crystallization) of the cast piece within its mold.



    Not exactly:

    If carbon solidifies last, then that helps to prove my point that carbides will
    tend to accumulate along the grain boundaries
    , especially during internally uneven
    parts crystallization.


    I will grant you that >0.83% carbon content austenite (hypereutectoid steel),
    all other things being equal, is more prone to grain boundary carbide dendrites,
    but I do not at all agree that such dendrites are impossible or even rare in
    hypoeutectoid steels (especially such cast instead of forged).

    Does forging more effectively distribute dissimilar alloys within the austerite?
    Of course it does, that's one reason for the operation. There really can
    be no disagreement about that.

    Quality hot forging of carbon steel distributes the alloys, and the oil quench
    "freezes" this distribution in place for optimal strength.
    After nearly many
    hours of research into all this, I'm really astounded that the matter can
    seriously be called into question at all.

    Regards,
    Boston
     
    Last edited: Jan 29, 2008
  23. daniel (australia)

    daniel (australia) Member

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    Looking back at my last post I should correct something I wrote – not that it changes the thrust of the argument but because I misstated something inadvertently, and it should be fixed: it is of course the generally the metastable austenite which nucleates first. Ferrite then appears as a transformation product from the austenite with decreasing temperature, and finally at about 720 degrees C the remaining austenite undergoes an isothermal transformation to pearlite.
    Well, yeah, but in the hypoeutectoid alloy, cooled slowly enough to avoid transformation to martensite or bainite, the carbide is all in the form of pearlite, which is a fine laminated structure – fine layers of hard carbide and soft ferrite combining to make a comparatively strong and tough structure.
    No, no, no! In the annealed or normalised condition you are going to have the same percentages of pearlite and ferrite for any given composition, regardless of whether the steel was forged, machined from bar stock or produced as a casting. You then heat treat. Further, the carbide in these grades isn’t precipitated out of the austenite, nor does it form segregated cementites. Instead the remaining austenite transforms isothermally to the new structure, pearlite.
    You are confusing a couple of important points here. First, investment castings are, in my experience, poured into investments (moulds) which have been preheated in a furnace to about 1000 degrees Celsius or so, and allowed to cool over a period of hours. It is not equilibrium cooling but nor is it anywhere near being quenching. You then clean off the mould material, do any finish machining and of course you are then at liberty to heat treat them any way you like. The same is true of forgings: you forge at temperatures above the austenite transformation temperature, cool slowly, and generally do your machining in the same normalised state, before heat treating to develop the final hardness. The reason is fairly simple: it is easier to do any machining before hardening. In either case though whenever you are ready you can quench and temper the product, or use some other heat treatment, to get the final properties you want.

    Except to the extent that, in direct contradiction of your earlier claims, carbides just don’t “segregate into dendrites” in these alloys.
    The carbide appears as the result of an isothermal transformation in the solid state. It is a different mechanism from that which causes impurities to tend to concentrate at grain boundaries. In fact the carbide is exceptionally finely distributed within islands of pearlite, not at grain boundaries. As you approach 0.8%C the pearlite % increases to 100%.

    Here’s a 0.3%C steel, normalised: the ferrite grains are white, the pearlite darker – you can see the laminated structure:

    [​IMG]

    At 0.4%, again normalised, you can see theres rather more pearlite, and less ferrite:

    [​IMG]

    And at 0.8% C, its pretty much all pearlite:

    [​IMG]





    More effectively than what? The austenite is a solution, not dissimilar alloys, and the metal is effectively mixed in the case of modern castings by a number of factors, including the churning which takes place in an induction furnace,gating and pouring processes etc. Any minor degree of segregation is easily attended to by heat treating anyway. There’s also processes like ultrasonic vibration to nucleate a fine structure, as well as various alloy additions to nucleate grains, pin growth, modify or remove inclusions etc– quite a bit is going on in fact.

    Well I suppose that is one way of putting it. It just isn’t a very accurate way of putting it.

    Let us not lose sight of the point though, that there are other processes besides forging which can give rise to a product equally suitable in terms of strength and other properties. Modern investment casting is one such process, and as I have previously said there is no technical reason why an investment cast receiver, all else (in terms of heat treatment, QA etc) being equal should be any less serviceable and safe than a forged one.

    I do hope that the research you’ve done has sparked a bit of an interest, even though it is a bit late for your book
     
  24. Boston T. Party

    Boston T. Party Member

    Joined:
    Feb 6, 2006
    Messages:
    90
    Thanks, Daniel, for your reply.

    Since McClung's thesis in my book (and thus its discouragement
    of cast steel receivers) points to the side of caution, even if such
    is ever proven technically to have been in error, my readers will not have
    been deprived of any safety or value because of that error.


    ___________
    Are you contending that gun parts/receivers are generally made of
    softer pearlitic steel (subsequently heat treated) vs. martensitic steel?

    Further, are you contending that heat treating transforms pearlite into martensite?

    I will respond to the rest of your reply when I can, but meanwhile reiterate
    to you my previously unanswered question:

    To me, this is the real question.

    Neither I nor McClung disallow that a sufficiently heavier cast
    receiver can have a similar working strength as a lighter forged one -- just
    that such is 1) heavier, and 2) less robust over time. Your disagreement
    with 2) is certainly noted, but are you also disagreeing with 1)?

    Regards,
    Boston

     
  25. hubel458

    hubel458 Member

    Joined:
    Mar 1, 2003
    Messages:
    693
    Location:
    Brinton,Mich.
    Properly investment cast, heat treated, alloy recievers
    and bolts are as strong as a forged ones, of the
    same dimensions. Winchesters are a little thicker on
    the side compared to Ruger and not even a Winchester nut
    would say it would hold as much as a Ruger. Ed
     
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