1095 - No soak

[BChou-E29]

I've often seen makers who claim they simply bring 1095 to critical temp. and quench with no soak. However, after reading one of Kevin Cashen's posts about 1095 HT, he said that the soak was essential to proper HT. If this is true, why do so many makers choose to ignore this step? Also, what are the consequences of skipping the soak and going straight to quench after reaching critical? Thanks guys

 

[mete]

If you want full performance from the blade it must be HTed correctly. Read that sticky on hypereutectoid steels and do it right !
Shortcuts in HT will will give you blades short on properties !

 

[Kevin R. Cashen]

All a knife really has to do in order to be viewed as a success is cut things softer than itself, really not that tall of an order if you consider that even if your as quenched hardness manages a feeble 55 HRC it will still be much harder than most of the things it will encounter. Add to this the fact that most have no idea what that HRC is since they feel a quick skate of a file tells them everything they need to know.

You may be distilling the hypereutectoid sticky down a little too much. The real key to a steel with more than .80% carbon is to control the temperature, it is much more critical than a steel that is at or below .8% carbon. But yet we still need proper solution, so the most effective route is to lower the austenitizing temperature and hold it there longer to accomplish our goals. A look through any proper HT specs such as "The Heat Treater's Guide" will reveal that the recommendation for 1084 is around 25F degrees higher than 1095. With 1084 all you have to work with is around .8% carbon so you have the freedom to heat for different times at other temperatures, but with 1095 you have extra carbon that you have to keep a leash on in order to keep it out of mischief.

As to why so many makers feel they do just fine while ignoring these issues, your guess is as good as mine. But I would point out the number of makers who have tried 1095 and have taken a dislike to it or prefer to stick with 1084 after encountering issues they couldn't work out. Issues that are easily worked around if you understand the principles described above.

 

[Tai Goo]

I’ve never heard anyone say specifically that 1095 doesn’t need any soak time,… but have heard the quenching process described as bringing it up to critical and quenching it. It is true that the blade is heated to above non magnetic and quenched. So, I figure it’s just a communication and linguistic shortcut rather than an actual shortcut in heat treating,... and maybe some false assumptions about other smiths heat treating based on very few words.

A quick file skate test really won’t tell you everything you need to know about a blade, but neither will any other single test. However, I think we should be aware that a quick file skate test is not the same thing as serious hardness testing using files. To describe hardness testing using files as simply, “it skated a file” may also often be just a shortcut in verbal communication.

 

[Tai Goo]

That being said,… I personally think that there are many cases where smiths do heat 1095 and other even more complex critical alloys to critical, with no soak time and go straight to the quench. This could be for several reasons which involve countless variables, such as equipment, methods for judging temperatures, understanding of the materials and circumstances in general. Also, depending on what the immediate goals are or intent is,… idealistically optimizing the steel may or may not be as important, practical or as necessary as simply getting the blades cut softer materials in the manner in which they were intended, such as Kevin already mentioned.


… just a thought.