Not exactly ''just'' heat treating..

[Vito]

Hello everyone,

I'm in the middle of the anvil making process. I'm stuck with a big block of mild steel that I wish to properly hard-face it.

I have already done that before but with different steel, that's why I'm asking how to do it.

I have a 12''x4''x1'' plate of H11, hot work tool steel. I want to weld that plate on top of that mild steel base in order to provide a hard surface.
The thing that bothers me is the effect of shrinking/expanding metal during the process.

I intend to heat treat that plate PRIOR to welding.

I've seen a guy on youtube that welded a plate of 4140 on mild steel block and then he quenched it AFTER welding...I can only imagine that EXTREME stress occured in the weld areas during rapid cooling, but it seemed that everything was fine.

Now, do you think that this would work:

1)Do a normalizing phase and thermal cycling, let that plate cool.

2) Heat it up to 1000 celsius, hold, air quench.
3)Preheat the surfaces to be welded, to 500 celsius

4)welding, maintaining preheat temp. throughout the process, cool very slowly when finished to enable hydrogen escape.

?

 

Please, let me know your opinions on this one.
Thanks, Vito

 

[Charles R. Stevens]

I have limited welding experiance as to exotic steels, and no pratical experiance with "H11" but I do have some exleriance with welding a plate on an anvil. The normal method would be to "forge weld the tool steel llate on and then quench either with a "quench plate" or a gravity fed stream from a sluce. 

Now as to what I have done is to do full penetration welds under the plate. Its a bit of a Pain but doable. One needs a bit of room to work so grinding, forging or milling the body to a bit if a peak is a good thing. Placing a peice of round on the peak (down the center) to start your welds to is also good, and then curving the top plate doen its length to counter weld srinkage is also helpfull. Use a low slag/flux rod for the root passes. what rod? What ever the suplier recomends. 

As to your plan to heat treat the plate first, if you stay below the temp to reduce the hardness below rockwell 55 or so it should work, but I am not an exotic process welder nor a metallurgist. I would recomend trying it on a small stake anvil or hammer first. 

Is "H11" and the rod to weld it up cheaper than hard facing or high alloy rod for facing the plate?

 

[ThomasPowers]

You want a full penetration weld so there is NO part of the face that is not solidly welded to the base.  Doing it with the proper preheat would make it very difficult to keep the face "cool"   what is the draw temp for the face plate?

[Vito]

Charles, thank you for reply. 

Will look up for high alloy welding rods, maybe that would be a better option, yes. We'll see, but for now I'm sticking with H11 plate for a face, because that's what I have.

Thomas, yes, root pass would be done with deep penetration rods (probably 6012). But nevertheless, you can't weld more than the outline of the plate, you know what I mean? Only the outline of the plate can be welded on, you can't weld UNDER the plate, it makes no sense, unless you do as Charles described. It's a hot work tool steel, so temper draw too far is not my concern...you BARELY start touching the temper of this steel at 500celsius, which is about right for welding preheat, so that should be fine.

Thank you both.

Best, Vito

[Steve Sells]

Why not? you do have to grind back the mild plate to expose more of the plate so you can access the  surfaces to weld.  I wont repost it, but this has already been covered in the anvil section.   I can not imagine why you choose 6012 good luck.

I fear you are getting ahead of yourself. There is nothing wrong with using the mild steel as an anvil as it is.  As you work you will learn more about metals, and can take the time to understand what you are trying to do, rather than diving in over your head, asking about process you clearly are not ready for yet.  Back up a bit and read and use your welding time to learn how to get thicker/wider sections welded up solid.

 

[ThomasPowers]

Yes you can and SHOULD weld under the entire plate.  This is commonly done by either using an offset sacrificial bar down the center of the piece or by beveling the base piece to allow for the  repeated passes needed.

[Vito]

Thanks.

Best, Vito

[Frosty]

Vito: The plan you're asking for help with is a plan made by a person without enough knowledge to make a successful plan. Not a shot at you here, we've all done it but experience has shown us we need to first gain the knowledge, then practice till we can make good plans.

First failure point is heat treating before welding. The HAZ (Heat Affected Zone) of welds WILL penetrate to the surface of your proposed face plate. PERIOD. This WILL damage or destroy any preexisting heat treatment. Period, end of story.

Second, perimeter welding the anvil face. WILL generate an overall DEAD anvil face. PERIOD. The main area of the face plate will be uncoupled to the body so impact energy will be poorly conducted and rebound will be negligent to nil. Try just laying the plate on the existing mild body and do a bearing or hammer rebound test. A perimeter weld won't improve rebound enough to consider.

A full penetration weld is no big thing but YOU need to know how to run a bead. I can not recall what the spacer down the center of the join is called but it's the easiest, fastest and best method I know of. Grinding a scarf capable of a proper joint like this is a LOT of grinding and will result in a taper that will increase draw warping of the face. Draw or pull is the force exerted by the filler cooling in the weld bead and WILL happen. To stop the pull warping the face you need blocks. ( again I can't recall the proper term) These not only maintain a consistent width to accept the weld bead but maintains sufficient space to get the rod in to weld.

I find about 3/8" is good space if you use a smooth finishing rod to fill, I've had good luck using 7024 Jet rod. It has good penetration and edge wetting but is a slow freeze so it lays down smooth and reasonably flat, the slag comes away easily and clean. Without a rounded bead there aren't corners where the bead meets the parent stock so slag is much less likely to be trapped. Jet rods require very little if any weaving so they're ideal for deep narrow fillets.

What you'll need do is place stops above each weld pass to prevent the face from pulling down onto the body. If you use a jet rod you can tilt the piece a LITTLE to help prevent slag from getting ahead of the puddle. Weld basically slightly flat uphand and drag the rod. The blocks can be just far enough from the bead to allow the welding rod in and NOT get caught in the bead. Step weld the first pass on both sides of the center spacer and alternate the steps. You're shooting on penetrating right through the center spacer so trying to weld it full length will warp the face.

Once you have a pass finished on one side flip the piece, insert blocks and weld a pass. Flip the block knock those blocks out, chip ANY slag and brush clean. Reinsert the blocks at the level for the next pass, weld, etc.  repeat till you have a last finish bead at the surface.

Allowing the piece to cool between passes is a really good idea but do the pass on each side THEN let it cool. You need to keep the entire piece as evenly heated as possible. It Is possible to warp heavy section steel like your proposed anvil body so keep an even strain on it.

Yeah, so ends Frosty's exercise in remembering practices close to 40 years old. Your best bet is to hire it out to someone certified to do heavy section and plate welding.

Frosty The Lucky.

[Dodge]

I made a mild steel anvil on a CNC flame cutting machine. I didn't hard face it. I was going to, but I didn't because  I was a production welder for over 18 years and was tired of welding and I wanted to start forging; not do more welding. Not to mention the copius amounts of grinding involved. Just sayin   Been using the anvil for a number of years now without an issue. No, I wouldn't use this one if I was doing this for 8 hours a day 5 days a week. I'd use my Trenton, but as a hobbyist I like my home made mild steel anvil just fine.

All that being said, another method of putting a hard face on mild steel, is hard facing rod. Usually a cushion layer is welded on of something like 7018(?) or maybe something harder and then the hard face. I have heard also of it being done, simply with 7018 rod.  It involves running stringer welds across the entire face (and one guy did his horn too) and grinding (or machining flat) There is a link somewhere in the show-me-your-anvil section of this process but I couldn't tell you what page. Mine is there too if you're interested

Scott 

 

 

Edited June 22, 2015 by Dodge

[Vito]

Frosty, thank you for this elaborate answer. 

Just two things: perimeter welding (with controlled interpass temperatures and cooling down before next side welds) would top out 600celsius of the whole plate?

As I have said before; You absolutely need to consider that H11 is capable of resisting temperatures as high as 600celsius before getting to soft for this purpose.
I'll probably ditch the plan, as I'm getting ahead of myself, I suppose, and just stick to forging.

Although I have been playing with the idea of hardfacing and then machining it flat. That would maybe be a  better (and cheaper) option.

 

Again, thank you for the recipe...will definately take it in consideration.

Best, Vito
 

[Vito]

I made a mild steel anvil on a CNC flame cutting machine. I didn't hard face it. I was going to, but I didn't because  I was a production welder for over 18 years and was tired of welding and I wanted to start forging; not do more welding. Not to mention the copius amounts of grinding involved. Just sayin   Been using the anvil for a number of years now without an issue. No, I wouldn't use this one if I was doing this for 8 hours a day 5 days a week. I'd use my Trenton, but as a hobbyist I like my home made mild steel anvil just fine.

All that being said, another method of putting a hard face on mild steel, is hard facing rod. Usually a cushion layer is welded on of something like 7018(?) or maybe something harder and then the hard face. I have heard also of it being done, simply with 7018 rod.  It involves running stringer welds across the entire face (and one guy did his horn too) and grinding (or machining flat) There is a link somewhere in the show-me-your-anvil section of this process but I couldn't tell you what page. Mine is there too if you're interested

Scott 

 

 

Dodge, thank you for that contributive answer. Yes, I am aware of the grinding but not worried about it as I machine all the surfaces that I want flat anyway (I'm not a believer of ''angle-grinder-flat'' surfaces).

Yes, I will probably hardface the surface and then machine it flat. Actually I am interested yes, I will search for it:)

Thanks Dodge

[Vito]

Another thing I forgot to mention in regard to Frosty's reply: I already have done that before (perimeter welding a piece of hardened and tempered steel on top of a mild steel to create a ''mini anvil'' for peening purposes. The temper did NOT get affected as much to make it too soft and the rebound was aprox. 75%. I'm still using it.

 

Best, Vito
 

[Charles R. Stevens]

Perimiter welding isnt worth the expense. Either go full penitration (space the plate so you can reach all the way to the middle) or surface the anvil with hRdfaceing or alloy rod. 

Edited June 23, 2015 by Charles R. Stevens

[Vito]

Charles yes, but now you (all the replying members) have reminded me that maybe welding a plate on, really isn't the best idea. And that way all of you helped me out solving a problem and I thank all of you for it.

Will try to get some pictures of the proces going and post it, if I make it (much commisions in regards to knifemaking lately) because I'm not sure how long will that take for me to acomplish. That also the main reason I'm not present most of the time on this forum. But things are turning out very good in the knifemaking business area lately so I'm happy but it takes most of my time also.


Anyway, thank you again.
All the best, Vito

[Charles R. Stevens]

Many welders/smiths have sucsefuly fully welded face plates on with electrical welding equipment (stick welding) if you have the plate, and can succfully heat treat it, its worth a try. I would try a smaller peice as a test, a 4x4" post anvil would be ideal, as you would be welding under the same conditions as a 4x12"+ plate. If you succed and it remaines hard you have taught us all a new trick. If not, heat treat

[Dodge]

Vito, I meant to repost sooner but I looked up my anvil post that was created in 2010. You probably already discovered that the pictures are no longer there. Seems that one of the upgrades spirits ate them. Anyway, here's one of them. The cutting process actually put a bit of surface hardness on it. You can dent it if you deliberately try but works nice for simple forging. It is actually corten weathering steel. Not sure of the hardness but its still considered mild...

Scott

 

[Vito]

Charles, I'll probably do a test piece of same thickness material first and see how it goes from there.
The only thing I'm worried about is interpass temperatures/time. Do you think that 300-320 celsius  would be a sensible temperature to use for preheat? As for interpass temperatures I was thinking of waiting till it drops to 500celsius before next weld.  What do you think?

Dodge, nice anvil. Sure you're happy to use it.

Thanks and all the best, Vito

[Charles R. Stevens]

I would have to ask welder friend for his take, but if you ask the rod manufacture/suplier for advice they should know. Most tool steels I have messed with needed 500F (260C)

[Vito]

Good, but I think that going a bit hotter shouldn't be a problem, correct? 
If you can, I would like to ask you to check this with your welder friend, I would appreciate that.
In the meantime, I'll ask in the local ''weldingshop'' and the rod manufacturer.

Thanks Charles,

 

Best, Vito

[Charles R. Stevens]

Data sheets say it tempers to RH54 at 1000F. Welds "by convitunal methods" 

ok, assuming you have the ability to harden it,  can quench in warm oil, 80C, pre heat to 325C and max interpas 475C. 

acualy looks beter than H13 as it can be water cooled at high temls with out cracking because of its relitively low carbon content.

Edited June 24, 2015 by Charles R. Stevens

[Vito]

Charles what steel are you referring to? Which steel tempers to 54HRC at 1000F? Sounds like 1045?

Sorry, I ''lost the thread''

Thank you and all the best, Vito

[Charles R. Stevens]

I googled the datta sheets and recomendations from several manufactures of "H11" tool steel. As it is relitivly low carbon, the hardness and air quench ability (up to about 1/2") comes from the other alloys. There for thermal shock of water cooling the steel in use and quenching in warm oil are posible

Edited June 26, 2015 by Charles R. Stevens

[Vito]

Charles thanks. I have also considered H11 as well but in the end I have opted for hard surfacing with appropriate rods.
I have already welded the buttering layer but I'm not sure if one layer is enough. I've welded the buttering layer with 7018 rods (2.5mm wire) and I'm planning on doing another layer in the opposite direction, just to ensure uniform thickness of the buttering layer across the surface. Do you think that's a good idea, or I should just leave one layer of that 7018 beads before hardsurfacing?

Thank you and all the best, Vito

[Charles R. Stevens]

Not my ball of wax, special process welding. But most the posts and tretuses I've read propose a single layer of a hard material faced with atleast a single layer of a harder material (some hard serface rods don't like multiple passes) I have also seen a move away from "hardfacing" that is abrasian resistant rod for earth moving equipment to specialty rods for tool and die repair. I see no reason that 7018 rod is going to in any way hurt you, at one or more passes. But somthing that aproches 50-55 rockwell harness and is impact/abrasian resistant is ideal. Esentialy a hard anvil and hammer should be more or less equal, but in favor of the anvil. Hammers are easer to dress and reforge.

[Frosty]

If you're going to hard face you need to use a build up rod intended to underlay hard facing then choose a hard facing rod intended for steel on stone. NOT steel on steel, abrasion resistant hard facing and does NOT like impacts, say missed hammer blows. Steel on stone is impact resistant hard facing and makes a good anvil face. This is rock crusher hard facing rod and no mere human is going to hit it hard enough with a hammer to damage it.

My advise if you hard face is to grind it while it's HOT or you'll be spending a lot of time and grinding disks getting a nice surface.

And yes, I've "repaired" an anvil with hard facing. I advised against it but the young man had a buzz box welder and was going to do it anyway. I know how and had the equipment to minimize the probability of ruining a darned nice old Hay Budden so I did it for him.

While not really necessary to preheat mild steel to build up and hard face it's a good idea, it reduces the shock fast chilling can do to hard facing. There is NO need to harden and temper steel on stone hard facing, just don't quench it at red heat or it's spall like crazy. If you can, grinding at low red with a cup stone will REALLY speed the process though you get to spend a while right next to a large piece of HOT steel.

Best of the best to you. It's a doable project if you don't over complicate it with prior expectations.

Frosty The Lucky.