Will heating destroy case hardening
Will heating destroy case hardening
(OP)
So have a gear thats a interference fit on a shaft. (by 0.08mm)
Both gear and shaft are some sort of nickel - chromium steel simular to en36a (but not necessarily so, detected composition by XRF and found closest match).
There case hardened, but not through hardened. (cutting a old gear is soft inside) But do not know the process used to harden. (suspect carburised, but its a mass produced item from a motorcycle gear box so who knows)
What to try and shrink fit assembly instead of press, But to expand the gear over the shaft would have to heat gear to a calculated 360C. Will this damage the case hardening of the gear? and any ideas as to what max temperture could be used used.





RE: Will heating destroy case hardening
I would limit the heat to less than 200 deg C to avoid softening the case.
http://www.interlloy.com.au/our-products/case-hard...
RE: Will heating destroy case hardening
RE: Will heating destroy case hardening
RE: Will heating destroy case hardening
I don't think slip fittings going to fly, after all.
Heating to 200C will expand by +.04mm
Freezing with dry ice -78C contract by -.02mm
Not enough need at least .09mm difference to be desirable easy slip on.
Could freeze with liquid nitrogen at -195C will contract maybe -.05mm,
so heat and freeze potentially works, BUT would have to buy nitrogen, not worth the expense, can just press it on... (Dang! need a bigger press!)
RE: Will heating destroy case hardening
RE: Will heating destroy case hardening