question about mystery steel

[fatalhubris]

I have a peace of steel that I got off a coast guard cutter’s deck a couple summers ago. We were installing some new boat launches aka davits. Question is would this make a good knife? Or am I just tilting at windmills here? It’s about 6x2 ½ and probably a little over 1/4th inch thick. I'm wondering if it will take any kind of temper because its mystery steel in other words I haven’t a clue what the metallurgical make up is. Other than it’s got a bit of rust on it. Guess ill try and see what I get even if it ends up in the bucket o junk…

Hubris

 

[Stacy E. Apelt - Bladesmith]

Let's step back and look at this question.....
You have a piece of metal that you don't know what it is.
We have never seen it.
You want someone to tell you if it is good?

Carnack the Great doesn't do knife steel.

OK, I got that out of my system...Just having a bit of fun.
There is no way to know if it will make a knife, but a good guess is ,NO.
It was not used in a function requiring hardness. A davit, and most all deck hardware is made for either strength or corrosion resistance. Most likely it is structural steel of .10 to .30 % carbon. If you want to do a spark test, you might get some inkling (provided you know how to read the sparks) of the carbon content. You can always quench it and see if it will harden. The real problem is that, even if there is enough carbon to harden the steel, you still won't know what it is or how to do the HT right. Use it for guards and such and make the blade out of a known steel.
Stacy