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Carbide inserts on 45-50RC weld...?

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  • Carbide inserts on 45-50RC weld...?

    I have a part that's been welded with some hardfacing rod. The box says two layers gives HRC 46-48, so that's what I'm assuming it'll be. I need to shave the weld down so it's level- no dimensions, just cut until the welds level out. Weld depth probably averages 1/4" thick over what's supposed to be high-manganese steel. (Train rail.)

    I have an R8 4-insert face cutter that uses TPU/TPG type 3/8" triangular inserts and a Bridgy clone to cut it on.

    Unfortunately, the first few passes will be somewhat interrupted due to the unevenness of the welds, so I'm figuring I'll take light passes to start with, then once it's down to just a few low spots, switch to fresh inserts (or at least a fresh corner) and make some finishing passes.

    Will this work? Any suggestions? The only other option is to get out the angle grinder and hog it flat-ish, then use a beltsander- assuming I could find some silicon carbide belts for it- to make it more or less flat from there.

    Given the size, annealing and then re-heat-treating is not an easy option.

    Doc.
    Doc's Machine. (Probably not what you expect.)

  • #2
    Hardfacing rod on manganese steel? Ouch. Unless you used a lot of preheat on the rail before welding you've got something in the mid-50's HRC, and I'd grind as much of as you can before milling. With that you've still going to eat endmills in any milling process, what you're working with is going to be pretty tough. Personally, I'd try and find a shop with a Blanchard grinder, or maybe someone with a 1" or better wheel on an automatic table.

    By the time you're done it might have been cheaper to buy an anvil.

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    • #3
      I may not know what I am talking about, but I would guess your hardfacing welds may actually be softer than that manganese steel. If I read correctly, though, you are not trying to cut into the train rail.

      A similar post here (Russ?) a while back about cutting welds ended in a solution that involved a bit more material removal per pass in order to get the job done before dulling the carbide. This seems to be the standard answer to cutting with carbide....more, light passes are not better from the tool life standpoint. There may be a fine line between a chipload that gets the job done before the cutter dulls and the chipload that results in broken inserts. Of course all rules of thumb go out the window if you take them to the extreme. I would experiment, trying for greatest chip removal short of insert breakage, but you may loose a corner of an insert in the process.

      Those are a positive insert and as such have a sort of "unsupported" tip that may be prone to fracturing, but should cut more easily with a small mill like the BP than a more durable negative rake insert. I have a 1-1/8" cutter that uses them and they do nicely for most stuff. Maybe someone with more tool archetecture knowledge than I will comment on just how suitable it is for this job.

      Paul
      Paul Carpenter
      Mapleton, IL

      Comment


      • #4
        Originally posted by rkepler
        By the time you're done it might have been cheaper to buy an anvil.
        -While I understand the sentiment, a good anvil is between $2 and $5 a pound, and toss in another $150 to get the thing shipped up here to Alaska. Best deal I've been able to find was a little over $300, delivered, for a 65 or 70-lb anvil. It said it was steel, but didn't say if it was hardfaced or not.

        Right now I have about $90 into a box of hardfacing rod (ten pounds.) Minus torch gas and the electricity it'll take to weld it, that'll be pretty much it.

        Yeah, it'll be some labor, but really only if I have to grind the bloody thing. If I can mill it, even taking light cuts might be some time but not a lot of effort. That, of course, presumes I don't kill a bunch of inserts, which is entirely possible.

        If I knew of somebody with a Blanchard, I'd do it, but the closest I can find is an automotive shop with a block decking mill, and that uses cutters, not a grinding wheel.

        I suppose I'll grind the top down some, probably use a chunk of flatbar and some Dykem to try and keep it relatively flat, and then skim-cut the top to get it all the way flat and more or less level.

        Doc.
        Doc's Machine. (Probably not what you expect.)

        Comment


        • #5
          I would try slow and heavy first,take 90% of the depth at 80 rpm with coolant and as much feed as the mill can stand.Reason is most of the hardfacing alloys I have worked with work harden,light passes may only serve to built in hard skins.
          I just need one more tool,just one!

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          • #6
            Any chance of being able to take a bite deep enought that you skip the high's and low's of the weld? That would keep the cutter engaged at least... Probably already tried that though?
            David from jax
            A serious accident is one that money can't fix.

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            • #7
              I would be pushing that carbide about 600 RPM if you have the HP ( Carbide LIKES speed!).
              and maybe 1/16 to 1/8 deep at most as the Triangle will not handle what a square will do. Get a piece of cork, like from a wine bottle, and make a drag for the spindle nose. you want to put just a little restraint on the cutter, so when it breaks through the weld piece, you do not clatter your headstock. Cork is good at this
              Put a shield around it, as you will be getting HOT chips. EYE Protection!
              I just cut a welded bearing off a part fro a friend. It was probably around 55 Rc and the weld broke 3 inserts, but it came off.
              Don't be afraid to push the cutter through the part.. you will see resistance.
              Do not use coolant..
              Carbide either wants to be totally immersed in coolant on none at all.
              Interupted coolant applications cause the carbide to crack due to thermo shock
              Rich
              You may want to try a C2 insert if your c6's do not hold.

              Comment


              • #8
                Thanks guys.

                Yeah, I already figured "no coolant"- I learned that one the hard way while facing some steel and tossing on "just a little' WD-40 out of pure habit. Inserts were already hot, so...

                I just read up on a fellow who built an anvil (or several, I think) from flame-cut 4" plate with hardfacing on the top. He ground, filled, ground again, filled some more and then polished, and it looks good in the pictures. I think I'll pick me up a big cup wheel and zap the top as best I can, fill a bit, grind again, and just use the mill for a cleanup pass.

                I can do 600RPM no problem- don't know about depth of cut, it's a 1-1/2HP, so I'm assuming I can at least shave off fifty thou in a pass. The face is far wider than the cutter, so it won't be too interrupted if I can cut deep enough.

                Doc.
                Doc's Machine. (Probably not what you expect.)

                Comment


                • #9
                  I'm surprised that you can't find an anvil in Alaska, I'd guess that it shouldn't be much harder than here in New Mexico. I did have to look for a long while before finding one, and that one had to be recovered as you're doing. A layer of 7018 and 2-3 layers of Stoody hardfacing rod.

                  Really, you can use an angle grinder on the face and get it more than flat enough for an anvil. It'll cup and dish in use anyway. I used a 7 1/2" angle grinder that scared the hell out of me, but it would take off a pound of metal (or 5 pounds of flesh) in a few seconds. I laid down the 7018 as a buffer then the hardface, took the hardface clean and filled in the missed spots.

                  I managed to destroy my right elbow in an accident a few months later and can't hardly use the anvil, but it still looks pretty good and has accrued no damage with the hammering I've managed to get in.

                  On the guy who flamecuts anvils - wasn't that Ernie Leimkuhler? Yeah, here's an article he wrote: http://www.metalwebnews.com/howto/anvil1/anvil2.html I haven't heard much from him lately, but them I don't hang in rec.crafts.metalworking much anymore either.

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                  • #10
                    Well, there's not many anvils up here ('cause they're heavy and costly to ship) and a fair demand for those that are up here, 'cause there's lots of do-it-yourselfers and plenty of both pro and am farriers. Therefore any time an anvil of any size and quality does go up for sale, it's snatched up lickety-split.

                    I've been looking for one off and on for ten years. It's like machine tools- every time one goes up for sale, it's snatched up within minutes.

                    And again, I could buy new and have it shipped up, but I'm looking at anywhere from $300 to $500, depending on size and quality. I have $90 in this so far, and apart from some work and maybe some grinding stones or two, I shouldn't have to spend much, if anything, more.

                    Doc.
                    Doc's Machine. (Probably not what you expect.)

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