Re: [CAD_CAM_EDM_DRO] cast iron

Jay, do you know of a source for programable controllers and high
temperature heating elements we could incorporate into home built electric
heating/melting furnaces?

I'd love to build a somewhat larger heat treating furnance and I know of
others who'd like to do this as well. In fact, I just got a post at
HomeFoundry about a guy that wants to build an elcectric furnace for
controlling temperatures on salt baths.

Smoke

>I set up heat treat furnaces for foundries. The heat profile for cast iron

can differ greatly depending on the type of cast iron,

>its thickness and geometry. The important factors are the ramp up, soak and

ramp down. Usually the temperature can ramp up rapidly

>to 600F. The ramp up is then tightly controlled at not more than a 200

degree F rise per hour until the soak temperature is reached

>. For some castings this could be 1050F or as high as 1650F, This

temperature is held for a soak cycle of two hours per inch of

>casting thickness. The casting is then slowly cooled in the ramp down cycle

at a rate of not less than 200 degrees F per hour, to

>600F. Often a fully loaded HT furnace will naturally ramp down if it is

shut down and bottled up at the end of the soak cycle.

>
>Aging castings is no where as effective as heat treating. Some castings

have an extremely tough skin that can take an edge right off

>a cutting bit. Aging won't help, but heat treating can make it cut like

butter.

>
>Hope this helps.
>
>Jay Hayes
>