Mete or Kevin??

[McAhron]

When austempering and marquenching,at what point do you fix any warpage?Im using salts.

 

[JCaswell]

Well, I'm not Mete or Kevin, but I correct minor warpage in marquenching just after the low-temp dunk (and before the piece cools to room temp. I suppose that the workpiece will be around 500F or so). It's pretty malleable at this point. Sometimes you can feel it stiffening up as you work on it, but there's usually plenty of time to tweak a little.

This is usually only on swords, though. (Very few instances of warpage with knives usually)

 

[mete]

With either you will be quenching into your low temperature salt at about 500 F. Marquenching -At this temperature the steel will be straightened easily as you're dealing with mostly austenite. If you take too long to straighten the temperature will drop and there will be more martensite and more difficult to straighten but you will have a reasonable time to work. With the austempering you want bainite but if you drop below the Ms you start to get martensite and end up with a mixed structure....If you've been having warping problems try to find out why and eliminate it at the source instead of correcting during the quench .

 

[McAhron]

Thanks guys for the responses.Im devoting a lot of time into making swords.I very very rarely get warpage on knives but was concerned with longer blades.