mild steel cracking?

[Pieter-Paul Derks 210]

Hello everyone,

 

This weekend (and a few before) I have been forging an axe for myself.

This axe was forged with the punch and drift method and the edge is file steel forge welded in a split

Overall I am very pleased with this axe as there are no weld flaws and the eye is well shaped and symmetrical.( the eye could be a bit bigger but I dare not make the side walls any thinner.)

As is custom when all is going according to plan, a problem soon showed up on my otherwise fine axe.

 

There is some sort of cracking where I fullered the transition between eye and body.

 

Normally I see this when the steel is burned, or when carbon steel is forged too cold.

However the axe body should be soft steel and I know fairly certain it never got hot enough to burn mild steel, else the edge had been burned up by then.

 

Any of the smiths on this forum know what may have caused this so I can avoid it for the future?

 

The two options I can think of are: either the mild steel is bad quality, (it was a scrapyard find, so it could be anything), or when fullering and drifting the eye, the steel got too cold and got damaged by my mighty hammerblows. 

[Alan Longmire 2,741]

My guess would be your mighty hammer blows at too low a heat, in combination with that little cold shut visible in that last pic.   Could also be crappy steel, of course.  Nice looking head, otherwise!

[Vern Wimmer 472]

I would go with,

"Circumstances beyond the control of the 'smith"

[Alan Longmire 2,741]

Was just trying to figure this out with another smith.  My new guess is you really drove the fuller in hard, which caused a sharp-edged bulge to form on the sides. A little too much heat on those thin flanges while trying to drive them back in flat, then fullering again, could account for it.  Thin edges do not upset well anyway, and it would explain the cold shut.  Maybe we need a new section called "Forging forensics: determining just exactly what you did without all the information to go by..."

[Joshua States 1,722]

Should be able to weld that back together no?

[Alan Longmire 2,741]

In my experience, once you get those little cracks they're permanent.  Welding doesn't seem to work on them.

[Jeroen Zuiderwijk 231]

In my experience, mild steel is very susceptible to cracking when working it too cold. One thing I learned was never to straighten a blade before putting it back into the forge f.e.

[Pieter-Paul Derks 210]

Forging forensics, I like that term 

I think you and your friend are on the right track Alan.

When fullering the sides bulged out considerably and I forged them flat and refullered them a few times.

The big fuller I used draws out a lot of heat, so it seems plausible  that the flanges got too cold and cracked.

I am not too worried about fixing the cracks, as the axe is for myself and is plenty thick enough to not break in use I believe.

Thanks for the help, constructive thinking like this is why this forum is the best 

[Vern Wimmer 472]

It looks to me like you have plenty of material there. I'd consider "going with the flow of the material" and doing some resizing/reshaping so I could grind out the small cracks in the mouse hole then if they reappeared I'd know they were a latent problem.

[Martin Brandt 3]

Last of all are you certain that was mild steel, (Spark tested), for lack of a more certain pedigree.  If more carbon than mild it would be even more prone to cracking if forged tool cool. just my 2 cents worth.  In either case it looks like forging too cool.