HELP! broken knife

[DANA HOLMAN]

Well guys, i was in the garage cleaning up a blade and noticed i had a little bend in the blade, i don't know if this happened in the heat treatment or when i stamped the blade, so i was trying to take it out and put in the vice and pulled 3-4 times and it just snapped, this blade was done as the same as all the rest, heat treated to nonmagnitic and tempered for 2-2hr, @ 400 degrees, now the inside of the steel looks good to me, nice gray color and creamy looking, like the ones that Karl and lin have put on the tread, so can anyone tell me why this happened
 
 
thanks for any help
Dana  

[Lin Rhea]

Dana,
       I will be out for a while and wont be able to help, but this part of your post is not clear:
   

heat treated to nonmagnitic  

I'm not picking on words, but please clarify this first. Also, what steel is it? Lin

[DANA HOLMAN]

Lin
this is 01 steel, i have always heated the blades to nonmagnetic and let it soak for about 20 min. then guence it in oil, then in the oven for 2-2 hr. tempering cycles,, this knife is about 3 1/2 inch blade 7 1/2 oal, and i had it in the vice about halfway trying to take the bend out of it, i just don't understand why it just snapped, with very little bend in the blade,
thanks dana

[kbaknife]

Need a little more info Dana.
How are you bringing it up to heat and how are you holding it there for 20 minutes?
Was this blade forged, and from what dimension steel?
Do you use reducing heats during your forging process? (Start forging with your highest heat and progressively reduce your heat throughout the forging process)
What were your post-forging steps taken?
What quenching oil do you use and at what temp?
Yor grain appears to be at least acceptable.
If, during the forging process, you let that steel get too cold and continued to forge, you may have induced a fracture that didn't communicate with you until it was too late.
Lots and lots of factors.

[DANA HOLMAN]

Karl
this is 01 steel that i bought from Jantz's so no forging, i'm still useing the one brick forge system with two propane torches, i heat up the forge and then insert the blade and bring it up to non-magnetic (temp. is really unknow) after it reaches non-magnetic, i let it set for 20 min., then in the veg oil @ about 120-140 degrees
, then in the oven for 2 hr.@ 400 degrees and let cool over night then the next day 2 hr.@ 400 degrees, i know that i'm not useing the right oil, but it's all i have for right now.
i'm thinking that i should had anealed it to take the bend out verses trying to bend it on the vice
thanks for any help
dana

[kbaknife]

My biggest concern is what the temp is for those 20 minutes that it is sitting in the one brick forge.
In such a small environment, the heat may be extremely high in localized areas. You may be getting irregular conversions throughout the blade's length.
First thing I would do with flat stock that will go through minimal treatment is to thermal cycle at least twice up to about 1500 or a little more, and then once again to just above non-magnetic and let cool to room temp before any stock removal is attempted.
Paying special attention to having the temp VERY equal throughout the blade each time.
On that last cycle, you might heat it up to non-mag and quicjly bury it in an insulating environment to allow for a little slower cooling.
Grind.
Thermal cycle once or twice again prior to hardening.
Shorten your soak time if you are stubborn about using O1. Because youreally don't have very precise control of your temp in a one brick forge.
Or switch to 1080-1084. ON those steels, you simply get them up to non-mag and quench and can end up with a nice knife.
Or do some 5160 and acetelyne austenizing just on the cutting edge.
Accomplishing what you want from a knife using O1 and a one brick forge is like going to Vegas.
No telling what you'll come home with.

[DANA HOLMAN]

Karl
thanks, i bought some 1095, will i get the same thing? i would like to know how everyone else knows how hot their forges get?(that do not have a klin) i do have a forge being made for me right now, and will soon be useing it,
dana

[kbaknife]

Now, this is just me, but if I had a larger forge being made, in which I could heat up the ENTIRE blade and not have hot spots, and in which I could have more control, I would not use my one brick forge ever again and I would wait until my new forge was in my shop before heat treating any more knives.  
But, that's just speaking for myself.
To answer your second question, that's where it REALLY PAYS to go to hammer-ins and seminars or other experienced knifemakers' shops to get some hands-on instruction.
When iron goes non-magnetic, (and it's the IRON in the steel that's going non-magnetic), the temp is somewhere around 1418 degrees.
That's too low to get a fully dissolved solution of austenite, which is necessary to create martensite with the proper quench.
Watch the colors that exist at the moment your steel goes non-magnetic by checking repeatedly as it comes up in temp.
Do this in a dark room.
Go back in the oven, all the while continually pulling the blade out and dipping the tip in your quenchant for brief periods of time to keep it from getting over-heated and so it "waits" for the remainder  of the blade to catch up.
When the ENTIRE blade has made it to the next color change above the one at non-magnetic, go ahead and quench.
This is for the really simple stuff like 1080-84-70.
You really want to watch 1095 that you don't over-heat it.
It's a little finicky.
But, of course, that's just the quenching part.
First you really need to set up the steel TO BE QUENCHED.
That's where pinning the grain size comes in and is something you learn while doing hands-on stuff with other makers, etc.
I diddled around for about 5 years, stumbling and bumbling my way through basic knife making and burning steel and not getting things hard, etc.
I really had no one in my immediate neighborhood to work with on a regular basis until I met a guy about 40 miles from where I lived.
It only took me a few visits before I realized I needed some serious help.
So, I went to the ABS school.
I went to get hands-on instruction.
I started going to hammer-ins and seminars, and still go - often!
Really changed the way I did things and made my much-desired progress so much easier.
Get your new forge. Find out some of the other things you need and get them.
You have an obvious desire to make great knives, and there is NO DOUBT that you will.
I found it a LOT more expensive and aggrevating to continue doing things the way I was rather than going to learn the correct way.
Sometimes it's easy to go ahead and play with knife making - but it's obvious you don't want to play.
Dive in and start reading some of the really in-depth stuff.
It'll all start making more and more sense as time goes by.
I'd be glad to email some links to you to read.

[DANA HOLMAN]

Thank you Karl
you are always a big help to us new guys, i hope this help others,as it has helped me. As you can tell i'm not afraid to ask questions. and if you don't mind i take all the web links you want to send
thanks again
dana

[kbaknife]

I'm going to take this opportunity to make a point here.
You asked the question in your previous post, "I bought some 1095, will I get the same thing?", and I didn't answer it.
Truth is, I have no idea.
It doesn't matter what steel you are using - it only matters what you do with it.
IF! you did the same thing with the 1095, then, yes, you probably would end up with the same result.
I hope everyone following this thread will indulge me on this one:
The success of ending up with a quality blade BEGINS in the forge, through the forging process, controlling the forging temperatures,on through the thermal cycling/normalizing/grain refinement steps, sub-critical annealing steps, post grinding steps, stress relief steps, austenising/hardening/quenching steps and the proper tempering steps.
That's a lot, and it is all called "Heat treating".
When a person says he "heat treated a blade", those are the steps taken.
Now, I've been through this before - at length - but too many times we have seen asked what temps to "temper" at and for how long.
Tempering is TOTALLY relevant to the success of grain refinement and full transformation from austenite to martensite.
Without those steps completely successful, tempering is almost irrelevant.
Consider that the steels we most commonly use in forging are - O1, 1070-80-84, 1095, 5160, 52100, W1, W2, L6, etc.
From the lowest to the highest austenizing temperatures, we only go from about 1450 - 1525. That's only a 75 degree window of ALL the steels we commonly use in forging! that's only a 5% difference.
So, you had better have some kind of an idea where your temps are and at least an elementary method of controlling them.
The difference in the austenizing methods of the steels I mentioned above is the amount of alloy, which will dictate HOW LONG to remain at the correct austenizing temps, and then having the correct quench oil to drop that temp to below about 900 degrees in the proper amount of time.
Look at it this way, you can austenize both W1 and 5160 at almost the same time and temp, but if you use the same oil on them both, only one will make a successful transformation into martensite.
W1 needs to get below 900 degress in about 1-2 seconds.
5160 can take about 7-8 seconds.
The oil that is designed to slooooooooooowly bring 5160 down, will NOT be fast enough for W1.
I guess my point is to not jump around from this type of steel to that type of steel hoping for success if you don't ALSO apply the correct heat treating process for that steel.
Without that, you're simply continuing processes that won't work for ANY steel!
It's not the steel - it's control of the process.
But first, if you TRULY want to succeed, get informed of what the processes are, and get equipped to exercise them.
For example, O1 does best when held at 1500 degrees for a good 20 minutes. The only way to do that is with a digitally controlled heat treating oven.
Oh, you could get it somewhat hard with a torch or maybe a charcoal forge and quench in transmission fluid, but you'd really only succeed in getting the fine edge properly hard, and truth is, that might be fine for some.
I'd say there's a bunch of people on this forum that want more than that.
Whew!

[TxMoon]

LIGHT BULB JUST BLEW UP~!!!! I Get it Thanks Karl I have heard this and heard this now I get what your saying...