Jump to content
Sign in to follow this  
Jan Ysselstein

Blade straightening after quench before tempering

Recommended Posts

Normally I straighten blades after tempering...I just read an instruction by a blade smith suggesting the blade is easy to straighten just after a differential quench to about 450 F ( quench oil temperature  at 450 F and a clayed spine and back of the blade...W-2, 203- E damascus . Doe anyone here use that type of a process?)

 

 

Share this post


Link to post
Share on other sites

Claying the spine will allow the formation of pearlite on the back of the blade which will be easier to straighten but the edge will still form martensite so you will have to straighten the blade before the conversion descends to near the Mf point.  It can be done but you timing has to be right.

Doug

Share this post


Link to post
Share on other sites

It can be done on any blade when it is between Ms start and Ms finish.  Quench past 900 degrees F fast enough to beat the nose of the TTT curve and then you have until it gets to around 450 F to tweak it.  There is no time limit, just temperature.

Share this post


Link to post
Share on other sites

this is why I have a large vice with aluminum plates set up right next to the quench tank

Share this post


Link to post
Share on other sites

Aluminium plates seems like a good idea to me because, according to what I have read, if the blade cools too slowly from MS start to finish it may auto temper the martensite and you end up with poor hardness. Is that right Alan?

Share this post


Link to post
Share on other sites

Thanks for the rep

lies guys...I like the idea of quenching quickly past the nose..my tendency to fumble makes me want to stay with tempering.

Share this post


Link to post
Share on other sites

When quenching long blades I clamp them between two heavy pieces of square tubing, this seems to press out any small warps.

on a 6mm thick blade I seem to have enough time to fumble with the clamps, I haven´t broken a blade yet with this method.

Share this post


Link to post
Share on other sites
2 hours ago, Joël Mercier said:

if the blade cools too slowly from MS start to finish it may auto temper the martensite and you end up with poor hardness. Is that right Alan?

I'm not Alan, but yes, you can indeed auto-temper, but your martensite generally isn't starting to form much above your final temper temperature, and you aren't staying that hot too long anyway.  But it is possible you won't see peak hardnesses.  B)

And generally Ms= martensite start, Mf = Martensite finish, and M90 is 90% completion.  So what we are really shooting for is straightening between the nose of the curve and Ms.  

  • Thanks 1

Share this post


Link to post
Share on other sites

What Jerrod said! :P

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...