Soaking 5160

[JTknives]

how long does 5160 need to soak at temp. i did some searching a got lots of diffrent ideas. some saying no need to soak and soaking it will inlarge grain size to it need to soak for 30min with a 24hr sit time between quenches. thanks.

 

[A C Richards]

JT,
In order to get the carbon into solution it should soak about 5 minutes. If you keep it at the proper temp you do not need to worry about grain growth. Waiting 24hrs between has not been proven to be beneficial. If it is done correctly one quench works (I feel better) than multiple. The more you heat and quench the more chances you have for to mess it up.

Chuck

 

[mete]

Chuck is right. The soak times increase with increasing carbon content and with increasing carbide formers especially W,V,Mo.

 

[JTknives]

what causes steel to desolve carbon slowley. i switched from O1 and that seamed to not need any soak time, does it disolve carbon faster. just trying to understand steel and its properties.

 

[A C Richards]

You have tungsten, and vanadium in O1 plus a higher Carbon content. All of these prevent the carbon going into solution. Thus requiring longer soak times. I would recommend checking out Kevin Cashins website sometime. Great info on HT and explaining steels and uses. Mete is also a wealth of knowledge, check out some of his posts. 5160 is a great steel and is very forgiving. You should get great results using it.

Chuck

 

[A C Richards]

I miss read your post, You may have had good results but not the best. In order to get the most out of your steel it must be heat treated properly. The best information can be found at steel sites and those that practice sound metalurgy.


Chuck

 

[JTknives]

what is his website address

 

[JTknives]

ok soaking for 5 min made all the diffrance. thank you so much.

 

[Kevin R. Cashen]

O-1 requires a soak just as 5160 does, but for different reasons, or perhaps the same reason but from different directions. Before we go any farther however, let me say that yes you will skate a file just fine with both of these steels after no soak at all, and if that is all one is looking for than you could stop reading now. However if you want true maximum hardness and proper carbon distribution you will need to soak. O1 will need to soak in order to move carbon around that is hindered in its movement by the alloying elements. 5160 will need to soak in order to over come a bit of this with chromium but also to distribute the carbon evenly through the ferrite grains. 5160 having .6% carbon at best will have around .2% proeutectoid ferrite to "carburize" for lack of a better simplistic word, and that is if the chromium isn't locking ANY of it up.

It is difficult to say however exactly how long you need to soak and that is why you will seldom see such times listed. You see it is highly dependant on what has been done to the steel prior. If you have already hardened the steel your soak can be no time at all since the carbon is already there and it will go into austenite solution almost instantly. If the blade was air cooled quickly and you have fine pearlite the soak time will be on the order of seconds, while with coarse pearlite it will be longer. if the steel is spheroidized as it was from the mill you will want to go for at least as long as coarse pearlite and probably then some. I prefer at least 5 minutes after the steel has reached temperature, and will increase this depending on alloying.

One good bit of news is that going longer is just fine regardless, if you have control over temperature there is nothhing to worry about. The nonsense that soak times cause grain growth needs to go away but unfortunately there are too many ingnorant people perpetuating that myth among bladesmiths. If they got large grains from taking longer in heating then they didn't have any control over their heat, it is that simple. I could drag up the old 5 hour O1 soak time thread but I think the point has been beaten to death on this forum. If you have control over your temperatures, soak as long as you need to make good austenite and be happy with no worries.

 

[Sam Salvati]

Also, Kevin don't forget soak times in a non oxidysing atmosphere also along with temperature control and there are no problems.

 

[Kevin R. Cashen]

Decarb is a whole other issue, but you can grind decarb away, carbon lean martensite you are stuck with.

 

[Sam Salvati]

Decarb is a whole other issue, but you can grind decarb away, carbon lean martensite you are stuck with.

Ahhh ok I see. This solves a bunch of problems, I think more than ever it is time for Salts........

 

[A C Richards]

This is were I like to send people who think steel is magic.....http://www.cashenblades.com/hype.html
From here you can get to the rest of Kevin's site.

Chuck

 

[Bruce Evans]

I always have a dumb answer for this.....

Take all the heat treat methods that every body gives you Then go to the smithy with your steel of choice and start experimenting...When you find a recipe that gives you the best possiable edge you can get then stick with it....

No 2 smiths will do everything exactly alike as no 2 smiths will have the same exact equipment set up Yes they may have the same forge but they may have things set up differently....you will have variables in every smithy that can range from ambiunt air temp ( the lowest temp your quench can reach) to lighting-humidity-etc-etc....You can get a different result between summer and winter quenches unless you forge and quench in a totally controlled atmosphere year round.....

Experimentation is a must to get your best blade...

Bruce

 

[mete]

One of the soak variables is the strength of the carbon/metal bond . The weakest is iron , then Cr and on the other end W,Mo,V.The stronger the bond the longer the soak....If you want fine spheroidized anneal , start with martensite and temper at 1200 F - this is subcritical anneal.