stonewalldiesel

Alpine, by heating any alloy to red hot will change its properties, and will effect the results. As the cryo process is an extension of the heat treating process you would probably have changed the rockwell hd of the part. It would become very brittle. think of this, if you have a part let's say you heat it red hot and cool it muliple times, each time you do this depending on the situation and alloy you are increasing the hardness each time until you reach a point where the part is like a piece of glass and it will shatter and fail. The same goes if you submurge a thick cross section piece of alloy(room temp.) in liquid nitrogen -320F that part will fracture or expold as the extremes that you have introduced it to are beyond the molecular makeup.

Haulin_in_Dixie

Yes and Liquid Natural Gas, dripping on a steel part will crack it. Also a four inch stream of LNG hitting a rock in the desert will make little rocks out of it Now how did I know that Interesting stuff cryogenics.

AlpineRAM

Thanks stonewall, I was thinking about the turbine wheel in some applications. (gassers) - basically their turbines do suffer from being heated up during wot and being cooled by off throttle during shifts and braking. I think that maybe we're gonna give it a try, hoping that we can increase the lifespan of the turbines a little.
What do you think?

AlpineRAM

stonewalldiesel

Hey Alpine, Well for what its worth I would say yes give it a go . Kind Regards Rey

ramguy

John H;
I was mearly passing along what I was told by the gentleman that runs the cyogenic process.
The heatreat process was preformed after my blades under went the cryo process.
Like someone on here said you've got try it.
The city of Wichita tried it on their mowers. They had one of three blades on each mower deck treated and had 1/3 the resarpening of the regular blades. the less you have to sharpen the longer they last.
ramguy

stonewalldiesel

As mentioned in earlier threads heat tempering of the material is necessary to complete the process.

shortround

In my younger days, as a squid, we would catch rats, which were always around the piers, and dip them in liquid nitrogen from the optics shop. After a couple of seconds, we would pull them out and toss them out the door into the parking lot. They would shatter like a light bulb, then they would thaw.

easilyentertainedShortround out

wannadiesel

The other fun thing to do with liquid nitrogen is to put a little bit in the bottom of a soda bottle, screw the cap on, and walk away. It's best to leave it near somebody who's already jumpy.

stonewalldiesel

Yeah Guys, there's lots of things you can do with liquid Nitrogen but don't ever get it on your body parts. Take a baloon full of air and submerse it in LN2 it will shrivel up to nothing, let it warm up and it'll resume its full shape again.

John H

Ramguy, the process only works by helping to complete the transformation process (from austenite to martensite - I was trying to keep away from the technical stuff, but someone else used it first) that occurs during quenching. You still have to temper the part to get the final properties. If the part fully transforms from the quench (which it does for most low to medium carbon and low alloy steels) or the part doesn't transform at all (like the aluminum alloys or stainless steel, or plastic or other things not metallic) then the cryogenic heat treatment is a waste of time. In the case of mower blades, they usually contain a higher amount of carbon, and when they transform they leave various amounts of retained austenite. This makes them softer. In some of the other high alloys, it gives them a tendency to distort during service (when the austenite finally does transform, since there is a 13% volume change when it does) or even sometimes crack.

John H

fireram

WOW, Great info on this,

Thanks Stonewall..

I will let my friend know that it can actually decrease his stopping efficiency, and should take this into consideration, As a volunteer fireman he has a very heavy right foot when the pager goes off !!!!!!!!