Anvil for building a power hammer, material question

[Patrick H]

Hello everyone.  This is my first post so thought I'd give a little background.  About 10 years ago I took a 6 week blacksmithing class put on by my local gild.  I enjoyed it greatly and acquired a nice anvil (late 1700/early 1800s Mouse Hole) and built a brake drum forge.  Life happens as it often does and I never ended up doing anything with them.  Now the kids are older and quite interested as well.  I am a habitual tinkerer and builder so have decided to build a power hammer.  I have a decent sized shop to work in and a mill, lathe, and shaper plus mig and tig welders.

Ok, long story short, I intend to build a Dupont linkage style hammer with a true disc style clutch rather than the tire style.  I acquired 2 steel blocks that I would like to use as the bottom anvil.  They measure 10" x 12" x 16".  Luckily they are stamped with the steel type on them but internet searches on that just keep sending me to nuclear reactor research documents.  Anyway, they are A508-CL2 (class 2) reactor pressure vessel steel.  They came out of the local nuclear plant when construction was shut down and everything was auctioned off in 1984-1985.  As near as I can tell these are forged blocks and considered NiMoCr steel.  Weight is in the ballpark of 550 pounds each.

I think they would work great for the anvil, what say the experts?

 

Thanks,

Patrick

 

 

[JHCC]

Welcome to IFI! If you haven't yet, please READ THIS FIRST!!!

I don't personally have any info about your steel, but I look forward to seeing how your project progresses.

[ThomasPowers]

If you will be using a bottom die mounted to that it doesn't really matter.  If you want to use them as the anvil rather like the Blacker hammer does then you need to know more details on carbon content and heat treat.   Remember "High Quality Steel" does NOT mean higher carbon or harder! I'm sure you could get aerospace grade 1005 for instance.

If you are having difficulties with getting info on it you might ask Jock across the street as his family used to build equipment for remote repair of Nuclear Power plants and may know where to look for the details.

[Frosty]

Welcome aboard Patrick, glad to have you. If you'll put your general location in the header you might be surprised how many members live within visiting distance.

How are you planning on using the mystery steel blocks in your power hammer? Have you tried drilling a hole or maybe taking a punch to it and see if it's something you can work with? 

Think about them physically, 16" would be a miserably low working height but full penetration welds to put them together would be no trivial task and not something mig let alone tig are suitable for. Doable but OH BABY what a job! If you laid the bottom one flat it'd make a decent foot and an overall height around oh, 26 1/2". Not bad for a sow block and if you can drill and tap the blocks you can make dies without machining dove tails.

IF you can weld and drill & tap the blocks you'd have a sweet sow block for a power hammer maybe up to 50 lbs. 

I don't know about using a disk clutch though, adapting auto parts is a fine old blacksmith tradition and you don't see disk clutches on home built power hammers. I don't know of one but what I don't know is legion. A long time ago I recall a trouble shooting discussion on theforge.list but don't recall if he ever got it working. You might ask on the list and see. ABANA may have it archived. 

There's a reason tire hammers are so popular. They're: simple, easy to build and effective. 

Frosty The Lucky.

[Chuck_Steak]

ASTM A502 is what you will want to search. Looks like there are 8-10 grades that are all in the low to medium carbon range, some with alloying, some plain carbon. Several grades can be class 2, so that doesn't pinpoint the chemistry.

Google Search turns up the standard for me.

[Irondragon Forge ClayWorks]

8 hours ago, Patrick H said:

They came out of the local nuclear plant

Have you checked them with a Geiger Counter yet?

[Patrick H]

Thanks for all the input.  The basic design I am looking to follow on the hammer is one built by Fred Connell and documented here:  http://ornamentalroseengine.com/smith/hammer/index.htm

The blocks I have can be welded quite easily using 7018 stick electrodes.  They each have a length of chain welded on to move them. My tig welder is a 300 amp transformer machine that stick welds very nicely.  If the rain lets up tonight I will drill a test hole.  I to make a bolt on bottom die so it can be changed down the road if I ever need to.  I am obviously still in the research stage and welcome all advice or opinions.  I didn't expect to find steel for the lower anvil this quickly so it kind of jump started the project.

[Irondragon Forge ClayWorks]

You might want to resize your pictures to say 500x375. We have members world wide and a lot of them have to rely upon dial up or have to pay for band width. Large pictures eat up band width and take forever to load for them.

[Frosty]

Found something good and grabbed it without knowing quite what to do with it did you?  I'm shocked, oh the humanity!

Join the club, most of us have large stockpiles of . . . useful things we've scrounged or been gifted. 

That should be plenty of elder, what's the duty cycle at say 120-150 amps? You can use a piece of 1/2" or 3/8" sq mild stock as a spacer between the blocks. 120 amps will produce 100% through 1/2" running 6011 or 7018. You'll need spacers on each side of the bead to prevent it pulling the blocks out of true. You'll want to stitch the welds switching between opposite sides of the main spacer to help keep the pull even. The fill in welds shrinks as it cools and is called "pulling". Dealing with pull is a major issue learning to weld but there are tricks. This is where the short pieces of sq. stock come in. You place them in the gap between the blocks so the beads can't pull them together as it cools. Yes?

Before you start welding determine what you want for tool height, end to end would make 32 1/2" high without bottom dies. Yes? These could make a SWEET power hammer and we'll help. 

Frosty The Lucky.

[BIGGUNDOCTOR]

As thick as they are I would be OK with a good edge bevel, and perimeter weld.

[Irondragon Forge ClayWorks]

My thoughts exactly.

[Frosty]

I have to agree, I'm starting to think full penetration weld around anvils as a knee jerk reaction. A good bevel and weld should work fine and heck if it breaks you can still go full penetration later. Joking here, it's so unlikely to break as to make that a silly thought. 

Frosty The Lucky.

[Chris Williams]

Since this is used in nuclear power, there are quite a few articles on it (most behind paywalls, however). A couple of articles from the NRC, and abstracts available from their European and Japanese counterparts, tell me the following: 

This steel should be quite ductile and resistant to fracture, which is why it is used in critical pressure vessel applications.  Through hardening thick sections is unreliable. It has good weldability, but is susceptible to hydrogen cracking upon cooling when exposed to hydrogen while molten (also correlated with residual stresses).

Based on that, I  recommend using a low hydrogen electrode. I also recommend a preheat of 500F+ or thereabouts. (I used the preheat chart here, and picked a preheat for between .45-.75% carbon). For the composition that I found (commercial site, so no link), carbon is up to .27%, molybdenum, manganese, and nickel should be between half and one percent, chrome should be between a quarter and a half percent, silicon a little less than that, & trace S, P, and V.  I used these to calculate the carbon equivalent range (from different formulas) that I provided above. The temperatures are close enough in that range that I wouldn't worry too much about the difference. It may not matter for your application, but I am no power hammer expert by anyone's estimation. 

[Patrick H]

I did finally get a chance to attack one with a drill and it drilled beautifully, reminded me of Stressproof.  I keep checking them at night but so far I can't detect any green glow.    I may have a couple of nice big 1" plates next week.  One will make the hammer base.  I see this thing getting heavy quick.

Thanks for finding that welding info Chris.

[Frosty]

Chris: These blocks show no obvious signs of having been welded to anything. Would they have been used in a pressure vessel and not been welded in? 

Frosty The Lucky.

[arftist]

I too believe a BIG perimeter weld would be sufficient, however, I would buy 50# of 110-18 and try to size the vee to use most of the box.

[Chris Williams]

You're welcome Patrick. 

Frosty, I was meaning to say that this type of steel is frequently used in such applications. I have no reason to suspect that these pieces were used or even were ever destined for use in a pressure vessel. 

[Frosty]

If I'd given it more thought I would've realized that. Those would be a pretty weird size and shape for part of a containment vessel. 

Frosty The Lucky.

[jason0012]

Probably meant to be feet, tabs, or shims under feet. ASTM codes are a pia but it looks pretty near 4130 from what I see. All the sites I found on Google want like $80 for a composition break down and I am not that curious. I could go look it up, but I am in for the night and dont feel like hiking back to the shop to look it  up. If you dont have a composition by morning I will find it for you.

Alloy aside, it really shouldn't matter. For an anvil you just need the mass. I would put them together with some big dowel pins then drill and tap the sides for threaded clamps and not bother with welding. That or use them as is for anvils and fond something else for a power hammer