Heat treatment of frames after welding.

[Neilios]

Can anyone shed any light on this for me, I have a CRF450 frame which is 6061 T6 which is being modified to fit a diferent engine.

This conversion means the frame is cut and extended and welded should the frame be heat treated to restore its strength. If so does anyone know where would do such an operation in the Newcastle area.

Many thanks.

 

[wyn]

I'm certain the CR frames are a 7xxx series alloy.

From everything i have read and heard about fitting CR 500 engines into aluminium frames no one has heat treated the frames afterwards.

Similar sort of thing in this thread.

 

[Blackjack]

Only thing I've ever seen about heat treating Honda Frames was a tech sheet about repairing CBR frames.

Basically that said to anneal it before you tried straightening it, and to leave it seven days to air harden.

 

[hotrodder]

I'm not 100% sure what alloys Honda used but have heard more references to 7xxx series than 6xxx. Heat treatment is totally different for each alloy!

From what Blackjack has said about Honda's repair procedure i'm guessing that a 7xxx series is more likely (or that it's designed for the T4 condition if a 6xxx series) and so natural aging (the 'leave it for a week' bit) will be your best bet. Returning a 6xxx series alloy to T6 isn't really practical as it requires both a solution heat treatment (cook and quench= distortion issues) and artificial aging

Blackjack,
Can you elaborate on annealing? Was a temperature/time specified or just the typical 'backyard' heat and cool (using soot/soap as a temp indicator)?

 

[Blackjack]

Blackjack,
Can you elaborate on annealing? Was a temperature/time specified or just the typical 'backyard' heat and cool (using soot/soap as a temp indicator)?

It did say temps and times.

But what it boiled down to was the same as the typical heat and cool cycle.

Ours clearly not being "backyard" as we are dead posh and use matchsticks for temp guides.

 

[hotrodder]

Fair enough, was just curious as textbooks give different temps for different alloys- might have been able to narrow the alloy with a bit of searching.

 

[Blackjack]

I would be suprised if it was that simple.

A typical bike frame will have cast, extruded, machined, and pressed components welded together.

Wouldn't amaze me to learn that the extrusion for the main beam was a different alloy from the extrusion for the lower rails...

 

[hotrodder]

Good point

 

[rodofgod]

Hi all!

http://www.alcoa.com/adip/catalog/pdf/Extruded_Alloy_6061.pdf

Regards