Carbide / Hardening / Casting

[Veselin Kolev]

I've got a few questions about metallurgy.

1. How hot do you need to heat steel to harden it? It melts at 1370 C, so I’m gonna guess about 1000. But could you use a welding torch set on a low flame to harden it a little? Like some sort of home-made hardened steel. Would there be any way to harden steel parts without having it professionally done?

2. Carbide is made by heating Si02 (sand) and carbon together at about 3000 C. Carbide is only a little heavier than aluminum. My question is, if you had that kind of heating capabilities, what would be the problem with making your own carbide and casting your robot frame? It would be interesting to have a robot made of carbide. By the way, is carbide restricted on the robots? I’m not 100% sure.

3. Does anyone know how hot a normal metal-working furnace gets? I’ve heard of one team that cast their gearboxes using sand-casting. It would be interesting to look into if my team can afford doing it.

I know it’s a little far fetched, but imagine it. You melt together sand and carbon, making liquid carbide. Pour it into castings, making bars. Use those bars to make your robot frame. Also, if you could harden your transmission gears and parts, like shifting dogs, your gearboxes would live longer. Just some wild ideas…

Good luck to all teams, ‘cause kickoff is in 13 hours!!!

[Adam Y.]

I know it’s a little far fetched, but imagine it. You melt together sand and carbon, making liquid carbide. Pour it into castings, making bars. Use those bars to make your robot frame. Also, if you could harden your transmission gears and parts, like shifting dogs, your gearboxes would live longer. Just some wild ideas…

http://www.mini-lathe.com/Anodizing/...g_aluminum.htm

[jrgrim12]

Hardening Steel:
How you harden steel depends on what kind of steel you have. If you want to harden the steel yourself then you would probably want to use o-1. O-1 is an oil hardening steel. Don't use any oil use something like this (http://library.cbest.chevron.com/lub...5?OpenDocument)
Some oils have low flash points and can bust into flames, or explode. But if you have the right oil then you heat the steel up with a torch until it starts to turn red. The brighter the red/orange the harder the steel will become. Once you have it heated then you quickly dunk it into the oil and quench it. It's a cheap and dirty way to do it. Remember usually the harder you make the steel the more brittle it will become.

I would suggest picking up a Machinery's handbook. It has a lot of useful information in it.

[Al Skierkiewicz]

I doubt that Carbide would fit into the allowed matierials list. Although it was one of the hardest matierials it is also very brittle and ungiving. It is not the choice for a robot frame that is going to get beat about and it is extremely hard to machine. Hardened matierials are not needed under normal robot building, although they are useful in bearing surfaces and guides.

[157#1Driver]

Hate to break it to ya, but if you even could make a frame out of carbide, it probably would shatter the first hit you took, plus it weights a crap ton more than steel does. I know cause I use carbide cutting tools at work and it they flex anymore than .002 of an inch, they shatter.