Does anyone here have experience machining Chapel Steel's AR500 or AR500F plate? Can it be milled and drilled OK with carbide? Is it possible to tap without thread milling or EDM? Thank you!
You've got my curiosity up! What are you making?
AR's nasty. I mistakeningly put AR in an ironworkers shear one time....(grunt)....(grunt).....LOUD!
Not a target for a gun range. Actually, I'm quoting some stuff for a customer that builds mining equipment and I know nothing about the abrasion resistant plate they seem to use for everything.
I've machined AR500 lately although I don't think it was from Chapel Steel.If they supply Catapillar then it is from them.It machined beautifully on the lathe with HSS.I don't have any carbide end mills handy and it was a little rough on those in HSS but everything came out fine.BTW,these were for a local mining company also.They were wear plates off a pan.
I used to work for a company that used it in armor applications. We drilled it with carbide die bits but it was tough. Slow speed and lots of coolant. It would be pretty hard to tap. I think EDM on a CNC orbital program would be best for threads.
We used to make lots of chute liners for screeners and stone crushers.
Let your customer know it's not worth it anymore to go with AR plate for wear surfaces (that is, if they are having severe wear issues). This new carbide-impregnated hardfaced steel strips outwears AR by 10:1, easy. Expensive stuff, but it's unreal how wear resistant it really is.
I'll let them know (I already brought up using Vanadis 10), but these parts are disposable, so we are trying to come up with something very wear resistant, but yet not super expensive. I have brought up that sometimes the more expensive parts are actually cheaper in the long run.
The local fabrication shop uses AR as wear plates on chutes for rock crushers and such. I can always tell when they're drilling the mounting bolt holes with the mag-base drills because of the awful high-pitch squealing. They use HSS spiral drills and go through them fairly quickly. Other than that, they treat it like regular plate steel. That's all I know about it.
Thanks for the help so far. I may end up quoting this using my usual system. That is: 1) Take a wild ass guess as to how, how much and how long 2) Lose my ass at first 3) Re-adjust just about everything about the job (how to do it, how much, how long) 4) Hit it again with some experience under my belt. Has gotten me through life so far!
Actually, I take on quite a bit of work I know little or nothing about doing. When everyone else says: "NO!", I start to get interested. Makes me learn stuff in a hurry!
That's exactly it, once you factor down-time, mechanics scrambling and operators sitting around scratching their asses...saving a few bucks ends up costing you a fortune.
I have brought up that sometimes the more expensive parts are actually cheaper in the long run.
We ran a stationary jaw, cone and a large screen deck with probably 15 conveyors...wear and its resulting problems was a daily problem (this was a very abrasive granite application).
Even though this special steel with this carbide substrate was like ~$100/sf for 1/2", it was worth its weight in gold because it stopped 80% of the wear problems. Mining's all about fast-paced tonage output, and this stuff really made a VERY noticable difference. But you only put this stuff in strategic places...that way you don't have to plaster the area in AR.
We used Cronaplate (from Cronatron Welding), there's a few other brands out there as well (and cheaper). Only way to cut it is plasma or waterjet, and it has a mild steel backing so you can weld it to what's existing.
You figure it out, AR500 stands for Abrasion Resistant 500 Brinnell! Converted, that's about 51 Rc.
Chapel is one of the vendors that makes this stuff. There isn't a lot of information other that it's hard and tough. About .25% carbon, some chrome, molybdemun, and manganese.
If I told you it machines just like 12L14 would you believe me? I didn't think so. It does grind nice. But it machines like crap. Waterjet or laser are the best.
JR, I was under the impression that AR's assocaited number (400, 500, 600 etc.) was it's MAX attainable hardness (through cold working), it doesn't come out of the mill at 500 Brinnel. But, regardless, it's still tough stuff to work with (and I think that has to do with its high manganesse content).
You figure it out, AR500 stands for Abrasion Resistant 500 Brinnell! Converted, that's about 51 Rc
According to this, 450 min., 500 nominal. Doesn't really give much info. about it though.
1) Take a wild ass guess as to how, how much and how long 2) Lose my ass at first 3) Re-adjust just about everything about the job (how to do it, how much, how long) 4) Hit it again with some experience under my belt.
And I thought no one else used my secret method!
We used tons of AR400 at work, with a little AR500 thrown in. Neither are pleasant, both are somewhat machineable.
AR500 hardness in Brinell: 450 minimum / 500 nominal.
AR400 hardness: 360 minimum / 400 nominal.
Both are quenched & tempered products. If your material is 1" or less in thickness, it will be hard from top to bottom. If 2" or thicker, you'll have 1/2" of hard plate on the top & bottom, the middle will be easily to machine.
Drilling with HSS bits isn't bad. Use strong flood coolant, speed around 10-12 SFM, as much feed as your machine & drill point can stand - .025 IPR is a typical number. The drill point should never squeal until it starts to dull. Grind the cutting edge for the least relief possible to avoid chipping. Thin the web to reduce drilling pressure.
Tapping with HSS taps, even hi-tech coated taps, is nearly impossible unless you spot anneal with a small rosebud.
Milling, like drilling, can be done at reduced speeds. Take your normal carbide speed & reduce by 1/3 to 1/2.
Pretty much sums it up.
Thanks Applied- I'm reading up on Chronaplate right now to see if it would work in this application.
Thanks JR- As much of this will be waterjet cut as possible, as it's actually very cost effective.
Sometimes cost vs. wear is a fine line to walk. I work on a bunch of plastic injection molds and associated equipment that can run 24/7 with very abrasive material. I make and replace many worn components of these molds. My customer tracks how much a replacement part costs vs. the number of parts it produces before it's worn out. Most are best made of Vanadis 10, which is very expensive and miserable to work with, but are cheaper overall when you look at the big picture. But some parts are still best made of something like D-2, which is cheaper (10x less than V-10) and easier to work with (LOL), and then just replaced more often. It all seems to depend on the size and complexity of the part being made, and if it creates downtime when it needs replacing. It actually gets to be an interesting little game trying to get the best bang for the buck.
Thanks Barry M. and everyone else! That should be enough info. for me to procede to Step 1 of the top secret super special quoting method. Step 2 where I actually pay for the experience is the painful part!
Just an update since I last posted on this thread a couple months ago. I made a sample AR500 prototype part (just 1 part), and lost quite a bit of time and money on it trying different things, but learned a ton. I knew that would happen, and did the part for the experience basically. I regrouped and quoted a short run of (6) AR500 parts, and came out OK on those. The AR500 plate machines fine using carbide and slower speeds and feeds. I can see where tapping with HSS would be almost impossible though. Luckily, all I had to do was milling and welding after the waterjet work was done. The (6) parts I just finished are now being tested, and it's possible that the next order could be for as many as 96 parts if they work out.
I'm assuming the Chronaplate that appliedproto brought up would wear much better in this application, but couldn't be machined using carbide? (I need to do c'bores and stuff that aren't through holes that can be waterjet cut)
As for doing counterbores/countersinks in the carbide substrate of that Cronaplate, I think you're out of luck. It generally seems to be for fabricating purposes, though you should give them a call if you're really interested. I think if you need machined features, grinding will be you're only possible solution.
Here's a Link :
On page 4 there's a description that says "Loader Bucket Liners", that's essentially what we did with it. There seems to be some thru-holes in the picture, but that's probably for more welding area.
Most any of the hard overlay materials will outwear AR400 by a factor of ten to one. As AP said, grinding is probably the best solution, although ram EDM should work as well.
I'm assuming the Chronaplate that appliedproto brought up would wear much better in this application,
We have some coal miner conveyor pans overlaid, but nothing is done to these areas after the overlay is applied. One of our engineers said that by the time bare AR400 is almost worn out, the carbide overlay is just starting to get a polished look