Cold temperatures induce blade chipping?

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Frisky

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Dec 1, 2010
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A YouTuber told me he likes the softer steel (HRC55-56) of Marttiini knives because they don't chip in cold weather as easily as harder blades. I told him I don't believe cold weather has an impact on blade performance, and edge geometry is more what he should be concerned about when it comes to chipping. So, can cold conditions (let's say well below zero) increase chipping?

Joe
 
I think it depends more on the HT quality and edge geometry. I used a 710-2 Benchmade in temps ranging from 5-15°F almost exclusively last winter for backpacking. No issues. And its run around 60.5-61hrc. Its not a brittle steel, but its not exactly 3V, either.
 
Frisky said:
So, can cold conditions (let's say well below zero) increase chipping?
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Fracture toughness of a steel is definitely decreased at cold temperatures. How much this affects chipping strength I don't really know.

The Titanic suffered significant steel fracturing, in very cold water. Samples of the hull plating have been tested and shown to have poor fracture toughness, and the cold water would have made that even worse.
 
Personal opinion only...I doubt it would affect your blade.
If you got it down to liquid nitrogen temperature, approx. minus 320 deg F, then I'd believe it. It could become brittle in that case.
However, tempering (or removing the temper) of a blade requires hundred of degrees in the other direction.
 
To avoid the splattering of your steel blade when dropped on the sidewalk at minus 40 F/C, just get a Titanium knife.
 
The temperatures that make a human uncomfortable do not make your steel knife uncomfortable. For almost all cases, the temperatures of your environment are not going to affect steel performance.
 
Watch you some "Ice Road Truckers". On that show, they experience NUMEROUS metal failures in the cold weather. Battery boxes have broke, frames have cracked & broke on the tractors & the trailers, rims, wheel studs, etc...etc. This is in temps from 0* F to -60* F. Prob not unless you are batoning or throwing or prying with it would it fail. Extreme cold does strange things to metal & alloys sometimes.
 
RevDevil said:
Metals can and do experience an increase in brittleness when exposed to prolonged cold temperatures.
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This is correct. This is why this trend of increasing rockwell hardness in blade steel seems a bit silly.
 
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I don't have a lot of experience using my knives in extreme cold but wouldn't keeping the knife close to the body when not in use keep the steel from getting too cold and minimize the risk of chipping? I know that's what folks do with camera batteries to minimize the power loss in them in extremely cold temperatures.
 
Thanks for the responses. Seems like there's no consensus though. I told the guy cryo treatments might be around minus 300 F. and I assume smoothes out the structure of steel. I'm not sure. I have noticed cutting into frozen materials is difficult and I suppose could chip a hard blade. Anyway, it is interesting. Here in MN, people ride their bicycles all winter and I've never seen or heard of frame or fork damage on steel-framed bikes, in spite of temps going well below zero. I have had both glass and plastic components break on my car in hot/cold extremes.

Joe
 
I recall reading a letter of testimony once written to Walter Brend about one of his knives (in a catalog or magazine) from a Marine who taught winter survival who told Brend that his Brend knife was the only one that hadn't chipped, cracked or broke among the other instructors knives after a few weeks.

I think it absolutely affects the blade steel, but only in prolonged BITTER cold, and hard use would it become a serious concern for most of us (and realistically most of us aren't going to be out there-even when I was winter hiking alot-I was seldom out more than overnight in temps around 0F-15F.)
 
I googled it and found this, but it's only on carbon steel:

"Exposure to low environment temperatures such as outside cold does not cause any sudden change to the nature of carbon steel. In fact, because of the carbon element, steel can resist cold better than other materials. However, at a certain point below freezing, the metal can completely freeze over. When that point occurs depends on how much carbon is in the steel. For practical purposes the steel will not freeze over in most normal weather conditions."

Brittle Effect in Cold
Carbon steel does lose its flexibility when exposed to cold, however. This condition, while the steel remains hard, causes it to be brittle and susceptible to cracking. U.S. Liberty ship crews found this problem out the hard way as hulls strained by cargo began to split up at the seams when travelingthrough cold Atlantic waters in World War II. So did the ill-fated Titanic. As a result, carbon steel needs to be mixed with other metals to retain flexibility at colder temperatures. Unmixed steel will reach a brittle point at less than -30 degrees Celsius. Many areas on the Earth reach colder temperatures.



Read more: http://www.ehow.com/info_8672716_lowtemperature-effects-carbon-steel.html#ixzz2e0TKM1Yd
 
I have almost destroyed the edge of my Gransfors axe this winter. I was just chopping 5 inch thick pine and blade gain rolled and chipped.
 
So EDCing my BK9 in Kansas winters for various jobs won't cause the blade to be negatively affected?
 
I don't even know why this is a debate. Practically all materials become more brittle in lower temperatures. How much and whether it is a concern at all depends on a plethora of other factors, such as steel type, heat treat, geometry, the user, and the intended use...

For metals like steel, there is a transition from ductile to brittle within a relatively short temperature variation. It is not a linear curve.

ductilebrittlegraph.png


If you feel up for some research, you could probably find academic papers in regards to the ductile-brittle transition temperature for various steels. They would probably be for annealed steels though.
 
Concat said:
I don't even know why this is a debate. Practically all materials become more brittle in lower temperatures. How much and whether it is a concern at all depends on a plethora of other factors, such as steel type, heat treat, geometry, the user, and the intended use...

For metals like steel, there is a transition from ductile to brittle within a relatively short temperature variation. It is not a linear curve.

ductilebrittlegraph.png


If you feel up for some research, you could probably find academic papers in regards to the ductile-brittle transition temperature for various steels. They would probably be for annealed steels though.
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The problem with this graph is there are no numbers. The temperatures and impact energies that apply to a human using a knife are not in the realm of concern.
 
The graph was just a visual to aid in understanding the ductile-brittle transition temperature.

And I can assure you that some steels do become brittle in temperatures encountered in the great outdoors... especially older steels. In modern steels the temperatures are likely very low, like -50C or lower still. But again, this is for annealed steel.

For the vast majority of users it isn't a concern. But people do live in areas that experience bitter conditions, so there is portion of the population that might want to research it further before settling on a knife. Imagine you're in the arctic and you need to sharpen your knife with a diamond rod. I could easily see someone chipping their knife under those circumstances.

Anyway, here's another chart with numbers. A36 steel of course isn't used for making blades, save for maybe some homemade stuff, but it does illustrate that the transition temperature can be high enough for steel to be of (SOME) concern for certain demographics. It's plainly obvious that there is a dramatic decrease in ductility.

Felkins-9801.fig.7.lg.gif
 
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Would definitely be interesting to see the same knife tested for edge retention and toughness in cold and hot environments.
 
dogstar said:
This is correct. This is why this trend of increasing rockwell hardness in blade steel seems a bit silly.
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Silly? You do realise not everywhere on Earth has the same climate right?
Where I live it rarely gets below 30. I'd trade off chipping resistance to a higher RC every time.
 
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