Low or high frequency induction hardening of 4140 1

[macquari]

Hello all I am trying to find out the best method for induction hardening 4140.
The material is thru hardened 30hrc of 76mm to 100plus diam.Required surface hardness is 52to 55hrc to a depth of 7mm/14mm diam.
We have 2 induction hardeners 1 is a low frequency up to 100mm diam and the second is high frequency which can do larger diams.My question is which is the best to achieve this spec without over hardening the surface? both require pre-heatig passes to achieve the required depth, note I am only the button pusher and have not had any technical training for this process but would appreciate any help and advice.

 

[arunmrao]

Higher the frequency lower is the depth of penetration,lesser is the depth of hardening.

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[macquari]

Thanks arunmrao I read redpickers reply to a previous post on rehardening a spline which made me realise we were getting different results from the 2 machines.Now we have to work out whether we change(if possible) the larger computurised machine to low frequency or increase the size capacity of the older machine which only has 2 heat settings and is controlled by speed selection and quench flow.We have had several technicians in setting up the new machine but I have not heard them mention this difference before,that's not saying they have not told anyone else as we work shifts.
Cheers macquari

 

[arunmrao]

if you can talk to some representative of Inductotherm,they will be glad to provide a detailed reply.

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[macquari]

Thanks again arunmrao
I searched google last night which was a lot easier once you put me on the right track and found some good info,tho I don't know the machine's outputs etc.
Will give the boss Inductotherm info and he can take it from there they have an associate company in Australia.
Cheers macquari.

 

[dbooker630]

You will probably require 3kHz frequency and 200 kW power. It does not sound like there is enough capacity if you have to preheat the blanks. Inductoheat will want to know your existing make and manufacturer, specifications, coil design, material and heat treat spec, before they are able to provide you with some valuable direction. They are very good to work with here in the US.

 

[macquari]

I had a look at the machine today their is no manufacturer id and the heat settings, frequencies etc are programmed through a computer by the technician who set it up,There are 2 gauges one for power input% and the other for volts and kilowatts, we set up following written instructions but have no idea of the machines capabilities so I'll have to leave it up to the boss if he wants to find out more.
Thanks again for the advice.

 

[arunmrao]

Secondary voltage,frequency,power drawn,amperes can provide a meaningful reply from any manufacturer. If you can talk to any technical support team with these details you can get a good response irrespective of the manufacturer.

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[arunmrao]

ASM is conducting a seminar "Induction Heating Technology and Application 2008" May 15-16,2008 at Monterrey Mexico.

Speakers are from Inductoheat,Pillar, Ajax Tocco Magnathermic, Radyne etc.

Perhaps you can get your issues resolved here and also learn more about induction heating.

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[macquari]

Thanks for the info again arunmrao and taking the time to reply. The people on this site are always a great help I only wish I could return some, I'll write all this down and when the technician comes in again I'll ask him a few questions and see if it all adds up, in the mean time will check out some info on google.The seminar sounds good but being in Australia I won't be going there.I have looked at the Ajax Toco web site previously when I was looking for info on rehardening damaged crankshaft journals.