Blacksmith's Welding quiz

[chipper]

I was forging a hawk this weekend with some unknown steel. I spark tested the steel and it had very little spark which lead me to believe it was lo carb. I planned to add a section of circular saw blade as the tip. I marked off what I thought would be a good sized head, found the middle and started heating. I bent the material in half and started throwing the charcoal to it, bringing it up to heat. It heated just like normal, applied borax and tried to weld. I did this three times, each time I was carefull to see the running butter but not hot enough for a sparkler. On that 3 time, the metal in the top layer broke apart into chunks the size of 1" squares. Not once did I over heat the metal.
Any suggestions what when wrong?

Regards
Loyd Shindelbower
Loveland Colorado

 

[LRB]

Loyd, is there any chance this steel was cast?

 

[ameling]

A lot of the recent generic iron/steel is re-melt stuff mixed together from melted scrap. The good mills try to do a good job to thoroughly mix up that scrap - to blend all the mystery steels together. But sometimes that mixing isn't as thorough as it should be. I have a friend who found a complete ball-bearing inside a piece of re-bar he was trying to cut to length. It never got completely melted and mixed/blended in.

So the lower end generic "welding shop" new steel can be something of a forge-welding mystery or lottery. Most of it will forge-weld fairly easily, but some of it will break/crack/crumble instead. You just never quite know what other metal alloys are mixed in. And spark testing mostly just shows you the carbon content.

So I suspect there were some weird other metal alloys blended into that bar of steel. But hard to really tell.

Just my humble thoughts to share. Take them as such.

Mikey - yee ol' grumpy German blacksmith out in the Hinterlands

p.s. Curious note: Some of the best forge-welding iron/steel is coming out of China. They are still making some iron from new ore instead of just re-melted scrap. I've got one stick of 3/4 angle iron marked Canada that I only use to weld up those Scandinavian laminated knife blades. It welds like a dream - and I learned the process from a Norwegian knife maker who loved that batch of iron also.

 

[chipper]

The stuff wasn't cast, so I suspect it was junk. I'm going to buy some more stuff and keep at it. I actually learned quite alot from this mess so I guess it wasn't a complete loss.
What I learned....
I could never quite keep the two side of the hawk together during the weld until I tied both sides together with a piece of wire.
So, now I bend, grind the weld surface, bend into shape, place the high carbon steel in place and wire the whole thing together tightly. When it comes up to temp, I add the flux continue to heat and then hammer weld with a pretty small hammer.

Thanks for the help so far fellas.

Regards
Loyd Shindelbower
Loveland Colorado