1095 hardening problems, rough day as a newbie

[Devin D]

Worked on a couple blades today and lets say it didn't go so well.  Made a 5 inch blade and a kukri ish style blade ) probably 16 inches long)  out of 1095.  Managed to crack the big one during hardening and slightly warp the smaller one.....and singe my beard when forge went out and reignited shooting a perfectly timed flame out.   Not entirely sure where I went wrong with the process.  

Started with the long blade.  Heated just above non magnetic, and quenched in canola oil....didn't seem to pass the file test.  Put through a normalizing run and let it cool for a couple hours.  Then did little knife in water.  Didn't notice slight warp.  So did the big one.  Got an almost perfect half circle crack and warp.   Not sure where I went really wrong.  Really frustrated with crack and even more with forge problems.  The burners keep getting hot and like blows itself out or ignites in burner tube.  

[Doug Crawford]

Water quenching is always risky even if everything else is done right. 1095 needs to get in the quench pretty fast. Did you preheat your oil? I've noticed that makes a pretty big difference. 

[Brian Dougherty]

Others can give you better advice on the burner tube, better than I.

About the quenching:

I bet your long blade hardened in the canola oil.  There was probably a decarb layer after the quench that was soft.  I have been fooled by this before as it can take a few strokes with a file to get through it before the file starts to skate.

Quenching 1095 in water is very risky at best.  I do it sometimes in brine with a thin clay coating, but it isn't something I would recommend for a first time.

The warp in the small can probably be fixed in the tempering oven by clamping it to a straight bar with shims in place to "Over straighten" it a bit.

Keep plugging along.  Three steps forward, two steps back

[Mason Simonet]

Another thing to add is to make sure you heat it a good bit over non magnetic. I usually get it to a bright orange, maybe a little over, And that's in night time darkness.

[Alan Longmire]

14 minutes ago, Mason Simonet said:

Another thing to add is to make sure you heat it a good bit over non magnetic. I usually get it to a bright orange, maybe a little over, And that's in night time darkness.

Actually, 1095 doesn't need to go too much over nonmagnetic.  That'll just give you grain growth.  About 50 degrees hotter is all you need, and then as fast as possible into hot canola.

[Mason Simonet]

Ahh, ok. I work with 1080 but thought 1095 was the same process.

[Jerrod Miller]

16 minutes ago, Mason Simonet said:

Ahh, ok. I work with 1080 but thought 1095 was the same process.

1095 needs to be slightly hotter than 1080, and 1080 only needs to be just above non-magnetic (as it goes into the quench, so a touch hotter if it takes a while to get from forge to quench tank).  

[Brian Dougherty]

1 hour ago, Alan Longmire said:

... and then as fast as possible into hot canola.

This is an important point.  With 1095, you literally only have a couple of seconds to get from the transition temperature to below 800 degrees F.  Don't dilly-dally when going from the forge to the oil.

[Alan Longmire]

52 minutes ago, Brian Dougherty said:

This is an important point.  With 1095, you literally only have a couple of seconds to get from the transition temperature to below 800 degrees F.  Don't dilly-dally when going from the forge to the oil.

Less than one second, actually.  That's why some people overheat it, so it will stay above the transformation point during the time it takes to get to the quench.  That is poor practice, however. 

[Vern Wimmer]

Ah, 1095. My first blade to be forged from real "store bought steel", instead of something re-purposed, was going to be a beauty and show what I could do. Trying to forge it to "perfect" probably didn't help much but when it came to the quench I was sure I was headed for fame, after all, they said it was a "water quenching" steel.......... No more being overly cautious with mystery steels and using "sissy" oil.......I didn't just hear the "ting" ,I was using long pliers, I felt it. An organic, holistic learning experience.

[Devin D]

Thanks for the info guys.   I just realized this time I didn't preheat the canola oil.  I did clean off the blade in am area before the file test, but the file still left marks on the blade.(not deep ones)  Unless that is normal..

[Alan Longmire]

That is normal for a few strokes if you have a bit of decarburization from an oxidizing forge atmosphere.  Once you get past that it should skate.  Unless the cold oil was too slow to harden it fully, of course.  The oil needs to be about 130 degrees F, just hot enough you don't want to leave your finger in it.

[Joël Mercier]

I realized I tend to get a little excited when the time comes to quench. So I make a list of things to do and NOT do before I begin . This way I won't forget to heat oil. Also won't put my knife in till the forge reached the right temp. Will also not forget to put a piece of wood inside the pipe to burn oxygen....etc

[Gary Mulkey]

Devin,

For  once I'm  going to stick my neck out and disagree with the  advice that you've been given here.  Firstly, 1095 is not a steel for beginners.  It  is  far too finicky on the heat treat.  You  have but .4 seconds to get it from 1475 to  below  the  pearlite nose and you won't  do  that  with canola  oil, heated to  120 or not.  If you really want to  stay with 1095, buy some  Park's 50.  Otherwise go to a more  forgiving steel  like 1084 or  5160 which will quench just fine in canola  oil.  Whatever steel that you  decide on using, try to  stay with it until you know it inside &  out.  If you  switch steels constantly, you will never know why one of  your  blades doesn't perform  like your  others and it's  because they  all  H/T differently.  [Make at least 50  blades of the  same steel before  going on  to  other steels.]

[Vern Wimmer]

1 hour ago, Joël Mercier said:

I realized I tend to get a little excited when the time comes to quench. So I make a list of things to do and NOT do before I begin . This way I won't forget to heat oil. Also won't put my knife in till the forge reached the right temp. Will also not forget to put a piece of wood inside the pipe to burn oxygen....etc

I have to constantly tell myself."Get  tempering oven up to heat BEFORE even getting forge to heat. Admire your your handiwork AFTER the first temper."

[Joël Mercier]

80crv2 seems relatively forgiving and also superior to 1084 for almost the same price. The vanadium helps slow grain growth and the steel overall receives a lot of praise from the community. They say it's basically 5160 toughness with 1084 hardness. My first knife is 1084 but my next ones will certainly be 80crv2.

[Jerrod Miller]

1 hour ago, Gary Mulkey said:

Devin,

For  once I'm  going to stick my neck out and disagree with the  advice that you've been given here.  Firstly, 1095 is not a steel for beginners.  It  is  far too finicky on the heat treat.  You  have but .4 seconds to get it from 1475 to  below  the  pearlite nose and you won't  do  that  with canola  oil, heated to  120 or not.  If you really want to  stay with 1095, buy some  Park's 50.  Otherwise go to a more  forgiving steel  like 1084 or  5160 which will quench just fine in canola  oil.  Whatever steel that you  decide on using, try to  stay with it until you know it inside &  out.  If you  switch steels constantly, you will never know why one of  your  blades doesn't perform  like your  others and it's  because they  all  H/T differently.  [Make at least 50  blades of the  same steel before  going on  to  other steels.]

Gary is right that this is not a beginner's steel (I still can't figure out why so many people are so fond of it, there are steels that will perform just as well that are way easier to HT).  I thought I'd pull out the good old ASM Heat Treater's Guide and take a look at the Isothermal (TTT) diagram for 1095.  There are 2 listed (sorry, I really don't feel like scanning them in at the moment).  The first one lists a composition of 0.89C and 0.29Mn.  Austenitized at 1625 *F, you have just under 1 second to beat the nose and about 3 seconds until 50% conversion.  The second chart lists a modified chemistry of 1.13C and 0.30Mn.  Austenitized at 1670 *F, you have just under 1 second to reach the 50% conversion line (the nose is in the "negative time" region, aka not possible).  The book also recommends quenching from 1475 *F (note the discrepancies in suggestion and charts given).  It says you can get full hardness in oil for rounds under 0.19" from that range.  Sadly, I don't have my book of just TTT diagrams with me at the moment for more reference.  

[GEzell]

From my experience, along with what the experts have written, 1095 can be oil hardened in thinner sections but you can expect the autohamon effect... I get a a little autohamon quenching 1095 in parks#50, and a lot in warmed canola.

From my experiments, agitation during the quench is extremely important with shallow hardening steels.  Plunge it into the oil, and use a slicing motion, waving the blade back and forth but NOT side to side until the blade has cooled to black.  Pull it out, check for warps and quickly straighten as needed, then back into the oil until it's cool enough to handle... Then wipe clean and into the tempering oven.

[Devin D]

On 9/29/2017 at 6:44 PM, GEzell said:

From my experience, along with what the experts have written, 1095 can be oil hardened in thinner sections but you can expect the autohamon effect... I get a a little autohamon quenching 1095 in parks#50, and a lot in warmed canola.

From my experiments, agitation during the quench is extremely important with shallow hardening steels.  Plunge it into the oil, and use a slicing motion, waving the blade back and forth but NOT side to side until the blade has cooled to black.  Pull it out, check for warps and quickly straighten as needed, then back into the oil until it's cool enough to handle... Then wipe clean and into the tempering oven.

How do you go about quickly straightening it without cracking it?  Doesnt the steel become very hard but brittle before the tempering part of the process?

[Devin D]

Thanks for all the replies guys.  I have a long ways to go lol.  Not that I didn't expect that, but wasting materials that are somewhat expensive considering shipping is always a bummer.

[Vern Wimmer]

1 hour ago, Devin D said:

How do you go about quickly straightening it without cracking it?  Doesnt the steel become very hard but brittle before the tempering part of the process?

Immediately after the blade is pulled from the quenchant (generall as soon as it loses color and goes gray/black) there is a small window of time when the blade is still pliable and can be straighten in th hands. It is a very short time but if one is prepared it can be enough. 

[GEzell]

You have a window between approximately 800° and 450° where the blade has missed the pearlite nose but hasn't started turning into martensite yet... That is, the blade is still soft.  During this time you can fix any warps by hand, with heavy gloves of course.  Once it drops below 400-450° martensite (hardened steel) begins to form and it starts becoming brittle.

[Devin D]

On 10/1/2017 at 11:01 PM, Vern Wimmer said:

Immediately after the blade is pulled from the quenchant (generall as soon as it loses color and goes gray/black) there is a small window of time when the blade is still pliable and can be straighten in th hands. It is a very short time but if one is prepared it can be enough. 

Would some sort of plates in a vice work?

[Zeb Camper]

Yes, check out the vise mounted thingies near the bottom of this post 

you can make much simpler ones, but you get the idea. 

[Devin D]

Would two flat plates the size of the knife work or do you need it setup so as to over correct ?