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Heat treating for Extreme Cold


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I shared an excerpt from John Rowland's Cache Lake Country with Robert Burns via PM, as I thought it was relevant to a thread he started a while ago about steel and cold temperatures. I thought I'd share it here to get wider input. The temperatures in question are extreme, as it gets down to about -25 to -40 C in that region--I'm pretty sure Cache Lake is Larder Lake (or somewhere near it), which has ties to Rowland's Cobalt mine days. Here's what Rowland's recommends to keep an axe from chipping.

 

 

"Your axe is your most valuable tool in the woods. In cold weather you have to be careful of it, for in temperatures far below zero metal gets so brittle it may chip. Once in a while you find an axe with such a high temper that it is as brittle as a stick of candy. The only cure for that is to heat the head to a dull red and then plunge it into a can of oil. I've seen the Chief use bear grease, but any heavy oil will serve. That treatment softens the metal and prevents chipping in low temperatures."

pg. 57 John J. Rowland's Cache Lake Country

It seems pretty obvious that "dull red" either means below critical, or the steel is low hardening and would normally be water quenched, but what would be happening metallurgically? What would be gained from quenching the steel rather than air cooling? Is this a legitimate method of preventing chipping/heat treatment?

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At face value of what you've quoted, I'd be inclined to see it as fiction writing, but the best way to get a true answer is to give it a try.

While you don't have the cold, you can certainly see what the result of a triple normalizing as outlined by Alan and then heating to dull red and oil quench.

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To me it sounds like a real rough description of "slack" quenching, quenching just under critical temp so you end up with a mixed structure instead of all martensite. Should make for a tough blade, although I suspect you'd also get poor edge retention and a "ragged" type of sharp edge.

 

It seems kind of a crude, homebrewed solution to a too-hard temper...although, with a working axe used daily, I suppose I'd rather have one that I have to sharpen frequently, than one with a big ol' chip out of the edge. I can't say as I've ever seen cold-embrittlement problems in a blade; it may be that it doesn't get cold enough here for such things.

My hand-forged knives and tools at Etsy.com: http://www.etsy.com/shop/oldschooltools

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Gerald, I'm inclined to think Rowlands is at least passing on knowledge he thought was valuable even if he may not have understood it or it was bad advice. If Farley "Hardly Knowit" Mowat, the great Canadian liar, had written the book, I wouldn't give the comment a second thought, but Rowland's advice has kept my snowshoes working and my .22 rifle from freezing up.

 

Orien, I like your thought that it's like a slack quench. I hadn't thought of that. I don't know for 100% certain that I've ever seen cold embrittlement either, but thinking about it, metal does seem to break more often in winter. My winter tent's zipper pull tabs didn't last too long at -15. I may have to suck it up and drive north in January to see what really happens at -35. Makes my bones ache just thinking about it.

Edited by Tyler Miller
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How old is the book? It is possible that this information is from a time when steel had more impurities (like sulfur) that made it more brittle in the cold. It sounds like a temper to extreme temperatures, which would leave the steel rather soft but maybe not as soft as a full anneal.

Having watched government for some time, it has become obvious that our government is no longer for the people. If the current trend continues, it won't be long untill armed rebellion is required.

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Question: At what temperature does steel lose it's temper? Dull red would be about 1200 degrees. Below A1 but well above what is normally used to temper.
Bear Grease would have been a very slow quench, not much chance of hardening unless the axe was made out of O1 and I wouldn't think O1 was used for axes.

If this was ever done, I'm more inclined to think the temper was gone and only the carbon content gave the axe any use.



Second question: How does one know that an axe has a high temper?





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I'd be willing to agree with you, Gerald, on your first point, that the axes lose their hardness entirely but I was hoping there was more to it than that. But I'd imagine the way these guys got to know the temper of their axes was use and getting "stuck" with a bad axe. These guys were in sled/snowmobile-only terrain and a long night requires a lot of firewood. As I said, though, it may be a bad technique.

 

The book was written between 1945 and 1947.

Edited by Tyler Miller
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I'd call it sort of a slack quench too. I'd also say it's a silly thing to do, but outdoorsmen have always had silly superstitions about how things actually work. I have heard of axes chipping in extreme cold, but never seen it either. Nor do I care to!

 

Down here the old timers used to say to burn the handle remains out of an axe eye when replacing a broken handle, and to oil quench from low red afterwards to "preserve the temper." That statement and the statement in your book tell me that once more some yahoo has confused hardening and tempering, thereby making a good tool less so, but still functional.

 

Then again, for most people on the street even now hardening and tempering steel is a kind of magic unknown to mere mortals, much less actually working steel hot. That's why you will never see an accurate description of smithing in any book not written by a smith, and never ever in a film.

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I have and do use an axe at temps that low on a regular basis here in Central Alaska. I've never had an axe blade chip on me. Lowest temp I went outside to cut wood was -50f. I won't be doing that again any time soon. But not because I'm worried about my axe chipping. Its just too durn uncomfortable. On the other hand a friend down the street a couple of years ago had an axel brake on him when he was gathering firewood. And it was in the -40s f that day.

Bryan

 

Virtuite et Armis (Virtue at Arms)

 

http://kbryanforge.wordpress.com/

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Alan Longmire, on 22 Oct 2013 - 15:32, said:

That's why you will never see an accurate description of smithing in any book not written by a smith, and never ever in a film.

A-ha! There is a description of fire welding in one of the Phillip Pullman Dark Materials trilogy. It's being done by a polar bear, which isn't super realistic, and at a sparkling heat, which isn't what I would do, but it is otherwise accurate. He credits a smith somewhere for telling him how it is done. Do I win a prize?
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A-ha! There is a description of fire welding in one of the Phillip Pullman Dark Materials trilogy. It's being done by a polar bear, which isn't super realistic, and at a sparkling heat, which isn't what I would do, but it is otherwise accurate. He credits a smith somewhere for telling him how it is done. Do I win a prize?

 

You would, were that not the subtle knife that cuts the boundaries between dimensions, which is where it loses all credibility. ;) Having watched certain smiths (Larry Harley coughcough ahem) perform sparkly-hot welds an armored polar bear doing it does not faze me. :lol:

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Especially when he's real big and not known for having an even temper :P I wonder what was in those rocks he used to protect the weld.

 

Doug

HELP...I'm a twenty year old trapped in the body of an old man!!!

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