modern stainlesses have higher carbon content why not tough as "high carbon" steels

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HepatitisJ

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Dec 3, 2010
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just looking at compositions of a bunch of steels. if elmax has 1.7% carbon an o1 has .9% why r carbon steels considered tougher?
 
I'm not a metallurgist but the addition of chromium must compromise the ability of the steel atoms to slip as the steel yields.
 
As far as I know, it has to do with all the other stuff added into a stainless steel. I don't think it's so simple as to say "more carbon=stronger". To the best of my very limited knowledge, a carbon based steel has far fewer ingredients in the recipe.
 
Higher carbon content will increases hardenbility while reduces impact toughness of steel.
The more alloy contain = more carbide form, alloy carbide will increases brittleness of steel .
 
Just a picky correction. Greater carbon increases hardness and hardenability. Hardenability is increased MUCH more effectively with other alloying elements. Hardenability is a measure of how quickly the steel has to be cooled to fully harden. Water < oil < air quench steels in order of least to greatest hardenability.

To the original question, too much Cr in the steel decreases toughness in a couple of ways. First, the above statement is right on, in that Cr forms carbides and higher carbide volume decreases toughness. Not all the Cr forms carbides. Some stays dissolved in the iron matrix. The Cr atoms strain the Fe lattice and, if there is too much, can decrease toughness. This is not unique to Cr, but thats what we are talking about here. Also, higher carbon in general decreases toughness. Comparing 0.9% to 1.7% is a little lopsided.

Note that these things are not hard and fast rules, but general guidelines. I think its safe to say 420 stainless is tougher than 1095, given the same hardness and other factors. Many exceptions exist.
 
To expand a bit on the above posts, modern stainless steels have been able to avoid many of the problems associated with high amounts of alloys like chromium by using particle or powder metallurgy. This helps prevent big clumps of carbides (bad; brittle, chippy edges) and promotes a very consistent, even structure within the steel itself (good; tough, better edge-holding).

So we now have true stainless steels that rival, (and in some cases surpass, depending on HT) plain carbon steels in toughness, while having excellent corrosion-resistance and wear-resistance. :thumbup:
 
awesome info guys. thanks. So in your opinions how would elmax perform against 52100 or 1095 for lateral stresses such as prying?
 
james terrio said:
To expand a bit on the above posts, modern stainless steels have been able to avoid many of the problems associated with high amounts of alloys like chromium by using particle or powder metallurgy. This helps prevent big clumps of carbides (bad; brittle, chippy edges) and promotes a very consistent, even structure within the steel itself (good; tough, better edge-holding).

So we now have true stainless steels that rival, (and in some cases surpass, depending on HT) plain carbon steels in toughness, while having excellent corrosion-resistance and wear-resistance. :thumbup:
Click to expand...

^This. :)
 
HepatitisJ said:
awesome info guys. thanks. So in your opinions how would elmax perform against 52100 or 1095 for lateral stresses such as prying?
Click to expand...

In that application, I'd side with 1095 or 52100. However, geometry is so heavily influential in prying, unless you have knives the exact same shape, you'd likely not notice the differences unless you bent or broke them.
 
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