Adding carbon to RR spikes

[Rog]

I have a theroretical question. Would forging in coke or charcoal, or case hardening an almost finished blade (then annealing) before finishing, bring the carbon up enough in a rail road spike to allow it to be hardened like other high carbon steels? Didn't iron blades pull in enough carbon (while being forged) to become steel during the iron age?

[Doug Lester]

In theory, iron does absorb carbon during forging in a high carbon fuel. Unfortunantly, it also loses carbon at the same time and, especially at higher temperatures, the rate of absorbsion is far less than the rate of loss. This is due to a chemical reaction between the carbon disolved in the iron and free oxygen or carbon dioxide present in the fire. That's why gas forges are tuned to run rich and produce carbon monoxide so as to reduce the oxidation of the carbon within the steel.

Now it is possible to incase the spike in a sealed vessle with a carbon sorce and heat it at high temperatures below the melting point for probably several days for something that thick and cause the spike to absorb more carbon throughout. That was basically how steel was produced before The Bessemer (sp) method was developed.

As far as case hardneing the steel, the problem with that is you would probably grind away the area of increased carbon during final shaping with files or on the grinder.

Then you will have the problem with the copper level in the alloy used to make railroad spikes. It would still decrease the hardness and wear resistance even though you increased the hardness and wear risistance by adding more carbon. Meaning that even if you increased the carbon content from 35 to 65 points of carbon, for example, you would still be better off getting some 1065. Even though the railroad spike with the increase carbon would deffinantly make a better knife than it would without the added carbon it would still be inferior to a bar of 1065. That's without considering the investment of time, effort, and money.

Doug

[Rog]

Thanks for the info. Been reading about alot of people useing the spikes, but complaine about the softness. So, why bother if they can't be improved?

[SBuzek]

Because they look cool but are strickly a novelty item.
Stan

[Rog]

Easy to find,and easy to learn on. Cool.

[WBE]

Look for RR spikes with HC on the head. If quenched in brine, they will get hard enough to make a good letter opener. Seriously though, they will get hard enough to cut light duty and short term.

[Rog]

I've never used them, but it looks like alot of people do, now I know why. Say, would they harden enought to make a fire stater, or would you have to case harden them like a frizzen? How about a throwing knife, or a patch knife? I have a few, might start play'n around a little. A color case hardened patch knife sounds cool.

[GHEzell]

I think the next one I make will have a w2 cutting edge san-maied in....

[larry franklin]

every thing i have read on r&r spikes puts them in around 1040/45 with the hc on the top.
wbe said it quench in brine and they do ok.

[Doug Lester]

Larry, that's rather high for high carbon railroad spikes. Someone posted specs for railroad spikes somewhere and I think they called for more like 30-35 points of carbon. That will still put them in the range of hardening with a brine quench and then a single temper cycle of 350 degrees just to relieve stress.

Doug

[WBE]

Yes. Doug is right. 30/35 carbon, and I didn't really say OK, but light duty, which I mean as very light duty. You might skin a rabbit with it before a touch up. I wouldn't bother with a temper. I seriously doubt there would be brittleness, even brine quenched.