over heated blade.

S

sharperedge

Member
I just heat treated my knife and it came out soft. I quenched in 130 degree canola oil. It was non magenetic but I think it got to hot. Is there Any way to save it
 
What steel did you use?I do realise that some water quenching steels could be hardened in light oils but it just do not work out sometimes.A rule of thumb for mystery steels is to cut 3 small pieces oil quench one second water 3rd aircool mark wich is wich and bang it with a hammer the one that shatters is your way of quenching.

If it is a known steel and was overheated you will be able to see it as overheating causes very distinct surface patterns as a result of the chemistry that will take place.If it was not too bad you could just normalise the steel again and have another go but if the carbon leeching was severe it will not be able to return to a workable state.

Also just as a footnote some steels have a so called soak time and if not adhered to one of two things could happen:

a) Too long and the steel will decarburize
b) Too little time the steel will not harden properly.

HTH.

Regards:
Shaun

Sent from my HUAWEI Y520-U22 using Tapatalk
 
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I used a old farriers rasp so I'm thinking 1095 or w2. I just got over my fear of water quenching and tried that and now the file skates over every thing but edge
 
Sounds about right as long as the file just barely bites if you edge quench be carefull as the blade will sori.

Regards:
Shaun

Sent from my HUAWEI Y520-U22 using Tapatalk
 
The upwards curvature of shallow hardening steels that is water and sometimes light oil quenched as is seen in katanas.the quenched part of the steel cools faster than the part above the quenchant and then causes a curvature due to faster contaction of the part cooling down as I understand it.

Regards:
Shaun

Sent from my HUAWEI Y520-U22 using Tapatalk
 
I did a full quench so it didn't do that but it did warp. I'm going to do one tempering cycle and try to straighten it. Then temper again
 
There is every possibility that your ferrier's rasp is a case hardened piece of junk. Yes, even if it's an old one and even if it says 'Simmonds' or 'Nicholson'.

Some ferrier's rasps were made out of good quality steel. Many are made out of case hardened junk steel.

If it hardened properly, you'd have a hard time cutting it with a file at all before tempering.
 
You might be right it did harden but not like I think it should of. I'm going to finish it and see how it performs. Next knife I make will be out of known metal.
 
Known metal is always the best way to go mate it seems like a big layout at first but the fact is that it is not.If you take into account the time spent along with fuel when forging,the peace of mind and also the satisfaction given by a sturdily made piece then the pro's will no doubt outweigh the cons.

Regards:
Shaun

Sent from my HUAWEI Y520-U22 using Tapatalk
 
J. Doyle said:
There is every possibility that your ferrier's rasp is a case hardened piece of junk. Yes, even if it's an old one and even if it says 'Simmonds' or 'Nicholson'.

Some ferrier's rasps were made out of good quality steel. Many are made out of case hardened junk steel.

If it hardened properly, you'd have a hard time cutting it with a file at all before tempering.
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John, Actually the case hardened junk steel was good steel for a rasp but made a lousy knife blade. I've been fooled a number of times with files and rasp because they were case hardened. If nothing else when using junk steel just heat the steel up to cherry and quench it in water. Hit it with a hammer and if it breaks like a piece of glass try it for a blade.
 
Raymond Richard said:
John, Actually the case hardened junk steel was good steel for a rasp but made a lousy knife blade. I've been fooled a number of times with files and rasp because they were case hardened. If nothing else when using junk steel just heat the steel up to cherry and quench it in water. Hit it with a hammer and if it breaks like a piece of glass try it for a blade.
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Good call Ray. yeah, that's probably a much better way to say it than what I typed. :D
 
J. Doyle said:
Good call Ray. yeah, that's probably a much better way to say it than what I typed. :D
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I thought you did fine with what you said.

Wayne Goddard and I were good friends for a number of years and at least once a year he would give me the junk steel he was wanting to get ride of. He'd always tell me he had a pile for me to take home after the OKCA Show. I got a great deal of old saw steel from him free of charge. I always enjoyed messing with the heat treat but found out most carbon steel hardens at or around 1500 degrees and the temper around 400 degrees give or take a few degrees. Pretty easy to adjust.

Wayne worked at a saw shop before he went full time knife. Got a few blades from there but he said most the time he would come home from work and a lumber mill saw blade would be resting against his garage door.
 
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