Mar quench and Austemp material

[grizzled gizzard]

I'm just wondering how many of you use these methods, and how. Where do you get the different temp salts?

Another salt question I'm having trouble with is that on high alloy (CPM type) steel, I have heard that my Evenheat may not get hot enough, and I'm wondering if I can get some really high temp salt to heat the blade before quenching.

I'm sorry if I'm way off base, I'm just a noob.

It seems like I've searched my fool head off trying to find the best oils and salts, and have come up with pitifully few answers.

Any help is deeply appreciated.

Thanks a bunch.

 

[mete]

You can get high temperature salts but I don't think the equipment and salts are for newbies .They can be dangerous.
Low temperature salts are available also and safer than running oil near the flash point . Austempering gets you bainite which really offers no benefits over martensite. For marquench a simple shape such as a blade doesn't really need it .If you use a good commercial quench it is designed to quickly go past the pearlite nose then slower through through the rest of the temperature range -exactly what you need.

 

[silver_pilate]

I haven't run into a steel that my Evenheat (22.5" 220V) won't work with. I have heat treated a whole bunch of CPM154 with no trouble (1925-1950F). Something like CPM10V or CPM90V might push the upper limits, but you should be able to hit 2000-2100F without trouble in your Evenheat.

To touch on the salt questions...I considered building a PID controlled salt tank a while back, but ruled it out. It's just too much danger and maintenance for what I do. Salt at 1500-2000F will erupt violently when it comes into contact with moisture. Splattering substances at that temperature will melt or light most things on fire including you. Not to mention, they may increase rust in your shop if not well maintained/stored.

--nathan

 

[grizzled gizzard]

Thank you very much, gentlemen.

I thought I had read some things on marquenching and austempering that sounded advanced, but do-able, and the results sounded... well, too good to be true, almost.

I take it that not many use these methods.

Please don't consider that as a man new to making knives that I haven't been taking it very very seriously. I am only interested in making the very best knives possible.

 

[silver_pilate]

Biggest things if you want to do salt tanks is to thoroughly research it and do it right. If you are going to skimp on anything, make sure it's not your salt setup. I'm not trying to discourage you from doing it, as salts can yield awesome, scale-free results with near absolute temperature control in both critical temp and quench temp. Just think about what you need and what you're willing to do. Many great makers use salts with great success. Many others just use an oven and quenching oils. Many use both .

--nathan

 

[Matthew Gregory]

Excerpted from Kevin Cashen's great thread All About Salt Baths:

TIP- Never, NEVER, NEVER, look directly into the top of a high temp tube or put your face over it for ANY reason, I have a little hand held mirror for that and beg you to do the same. I would look down the barrel of my 16gauge before I would put my face over that tube.

Why am I such a scaremonger when talking about these units?

This is just one reason. This is a blast/burn pattern left on a ceiling 14 feet above the floor when a 1500F NaCl shotgun with 5” diameter bore decides to go off. My hair and my clothing were on fire and my shop would have been if I had more wooden structure. All I had done was check a direct reading on some test pieces with a thermocouple that had a bad spot in the inconel sheathing, minutes later I was outside my shop, shaking, well burnt and assessing how much I would like to see my children grow up! This is just one incident among many I could share that occurred when I let my guard down for a second around these devices. Those who say they are not to be totally respected have been VERY lucky and are just getting by until their time comes. Please respect them and listen to any warnings people give.