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Hey Forum,

I think I forged about 12-15 hammers from 1045 yet and in the last months I have massive problems with them cracking during the quench.

  1. Picture 1-3 is the first hammer that cracked during the quench. I heard 3 times the horrific "ping" sound and here you go with a big crack right through the eye.
  2. Picture 4-5 is a rounding hammer that showed the same kind of crack as the first hammer. I heared no sound of cracking. I cracked it completely open to examine the grain and the crack itself. After this hammer cracked I assumed that I forged the steel too cold when drifting the eye. So I forged the next little 0.9 kg hammer a lot hotter. I will heat treat it the next week I think.
  3. What really confused me is the piece of steel in the last picture. I finished my guillotine tool today and tested it on this piece. Just a couple of heats and some hard hits with the hammer. After I finished I put the piece aside and shut down the forge. When I came back it wasnt red hot anymore but still hot (black heat). So I threw it in the water bucket to cool it down. After I looked at it I saw this big crack right through the fuller grove.

Iam at a point now where I dont know what to do next. Nearly every piece of 1045 cracks (Iam glad the guillotine dies did not). I forge everything by hand so its really frustrating to see the hard work going to pieces in the quench. Any tips/suggestions?

Those hammers are the first ones after changing from solid fuel to a gas forge. Can there be any connection to this? Iam thankful for every hint.

Thanks

Tim

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are you sure you're getting it hot all the way through the steel? not just at the surface while inside is cooler?

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Bitte shurn,  but generally changing forges means we need to adjust our procedures. and from solid to gas is also a heating speed difference

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Welcome aboard Tim, glad to have you.

Yes, there is a big difference between solid fuel and gas forge heat times. Burning coke in the solid fuel fire is in contact with the work so heat is conducted directly where a gas forge heats almost exclusively by radiation. 

Yes, there are charts regarding soak times in minutes per inch or mm from surface to center. For example a 100 mm round bar would be calculated for 50 mm, surface to center. Yes? I'm sure someone will produce the charts, they've been around for hundreds of years.

You allowed your hammer head to cool IN the shut down forge, yes? I'm betting only the outside of the hammer head was at black heat and the center was significantly hotter. When you cooled it water the outside cooled faster and shrunk while the inside was still expanded by temperature and couldn't be compressed. Something had to give and that was the thinner exterior. 

The last is just my thoughts and is NOT a hard fact.

Frosty The Lucky.

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Thank you Frosty.

That totally makes sense with the contact and radiation heating. Should have known that.

So I will look for those charts and adjust my heating time.

All hammer heads were allowed to cool down in the shut down forge after I finished forging. But no normalisation cycles between several heats or something.

The cracks in the test piece for the guillotine still confuse me. Its a piece of 25 x 30 mm and cooled down in air for like 10 minutes before i dropped it in water.

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Ah, we all need what we should've known pointed out to us, I live with what I call head slapper moments on a continuing basis. The learning curve is unending; it's so long we often loose sight of what we learned back when. 

When I anneal in the forge I leave them overnight thicker sections can still be warm to the touch next morning.

Oh, 25 x 30 and ONLY 10 minutes to cool in air before tossing it in . . . WATER!?! :o You deserved that one Tim! The ONLY thing being in a rush does consistently is make mistakes permanent more quickly. Don't do that again!:angry:

I have an expanded metal shelf on the spreaders under my forge I lay stock on to air cool and "normalize." Old school was to lay it on the dirt floor but my shop has a concrete floor and that chills too fast. Contact rather than convection cooling. I have an old single file cabinet/drawer thing I keep full of Perlite if I want stock closer to being annealed. 

Ah, don't you just LOVE learning how to use new equipment? I LOVE being on the learning curve, just because.

Frosty The Lucky.

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So I see what I messed up on the small part now. :D

I hope the hammers will stop cracking if I get the soak time and heat management right. I guess all I can do is to forge more hammers and keep trying.

Being on that learning curve is nice but also kinda depressing sometimes. Iam glad I singed up to this community.

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If I remember from the 1045 data sheet about forging it says hold till temperature is uniform (or something like that).

Quote

Pre heat to 750 oC - 800 oC, then continue heating to 1100 oC - 1200 oC maximum, hold until temperature is uniform throughout the section and commence forging immediately.Do not forge below 850 oC

Can't post a link to a commercial site.

Finished forgings may be air cooled

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You'll get your hammer heads right. 1045 is reasonably forgiving in heat treat. Might I suggest you experiment heat treating unforged hammer stock? Cut a piece or two of 1045 the size you use to forge hammer heads and experiment heat treating them. Once you get those consistently right experiment on ONE OR TWO forged hammer heads, the eye will make a difference in soak, quench and temper time. 

 You are going to fit in here so very well. It's refreshing to talk to adults who ask a question and don't get upset having mistakes pointed out or even getting a little friendly yelling at. 

Oh, we LOVE pictures.

Frosty The Lucky.

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Actually Iam here to to get my mistakes pointed out so Iam not upset at all. Frosty the Lucky

I actually found a formula that says for a unalloyed steel the soaktime should be 5 minutes for every 10 mm diameter/width and 10 minutes if alloyed.

Thank you Irondragon Forge & Clay. It was intended as a hammer for my striker.

"@" tagging removed. 

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I have watched a highly skilled hammersmith who uses 1045 and regularly quenches his hammers in water... with no adverse results.  He never just tossed them into the water though!  He would dip them and then pull them out.  Basically lowering the speed of his quench by his technique.  Water tends to be a very uneven coolant when the work is not carefully agitated.  This may have some bearing on your problems.  Personally I prefer oil quench for most purposes including hammers.  Severe cracking seems to suggest fairly serious stresses and maybe a combination of factors at work.  I suggest slowing down your whole process and being attentive to each step.  

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In regards to uneven heating in a gas forge. I rotate my stock in the forge to ensure there is an even soak,especially when working larger tool steel.

 

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Same thing in a solid fuel forge.  I even have a crank count I use when going for a billet weld. (or I chant that Monks chant from "MP&tHoly Grail")

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Alright guys,

I successfully hardened 2 hammers I forged again. I followed the charts for material thicknes and heating time that I found and it worked just fine. I assume it was a thing of getting used to the different heating rate in my gas forge.

The picture shows a hammer I made for my striker, He was in need of a good hammer at work for setting up machines ;)

 

Thanks again for your support!

hammer.PNG

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Good Morning Tim,

1045 is very forgiving Steel. I have made many Hammers with 1045, no cracking. Don't do any sudden quenching, until you start the Heat Treat. Hardening requires a sudden quench to lock the molecules in a Hardened state. Start your Temper as soon after as possible. I have seen Hammers crack after hardening and not Tempered (one sat in a drawer for a year. It cracked because of the internal tension from Hardening).

Neil

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On 2/13/2019 at 2:27 PM, Cast and Forge said:
  1.  
  2. Picture 4-5 is a rounding hammer that showed the same kind of crack as the first hammer. I heared no sound of cracking. I cracked it completely open to examine the grain and the crack itself. After this hammer cracked I assumed that I forged the steel too cold when drifting the eye. 

I just came across this thread. Do you notice the heat tint on the lower fracture of the hammer in pictures 4-5?  It cracked almost all the way through (the non-tinted portion wasn't cracked yet) either while it was still hot and exposed to oxygen, or else it was heated after cracking. I think you may be correct about when it cracked. 

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