I am just starting to make some 30degree squares. I will be making a set of four so that I can generate both the 90degree and the 30degree angles accurately. It would be nice to harden the cast iron (but not essential).
Can flame hardening be done in such a way that the affected depth is only a few thou and the distortion is minimal, or should I forget the idea? I don't fancy scraping a thou of chilled iron off about 150 square inches of area!
Mark Rand RTFM
Chilled Iron is done at the casting stage, and involved forced cooling of certain areas to get a tougher/harder skin than usual.
I didn't think you could flame harden cast iron once machined, but I would stand to be corrected on that.
Kind regards,
Peter
Peter Forbes Prepair Ltd Luton, UK email: snipped-for-privacy@easynet.co.uk home: snipped-for-privacy@easynet.co.uk
The ways on lathe beds are / were flame hardened after machining. A shaped oxy-acetylene flame is moved down the way at a speed that heats the outer skin which is then chilled by conduction with the body of the casting. This leaves a characteristic patina on the surface which is now hard.
I suspect that nowadays it is perhaps done with an induction process, again moving down the way and followed by a water jet to cool it.
Andrew Mawson Bromley, Kent, UK
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.