.....

The problem with many comparisons is what is being said isn't really what you think is being said. For example :

Maraging steel alloys are twice as hard as stainless steel and 35% stronger than the hardest titanium alloy.
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The comment about the hardness of Ti is about right, as Ti doesn't get much beyond ~45 RC. However the stainless comment seems a bit odd for it implies that Ti is harder than "stainless steel". More on that below.

... is two times harder than stainless steel and 85% harder than pure titanium.
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For a lot of people, the comment "pure titanium" would mean the best. In reality, alloys are much better materials.

The above is from :

http://clubmaker-online.com/mw.html

As Maraging steels are coming on strong in the golf industry right now.

If you say stainless steel on Bladeforums people will think you are talking about something like ATS-34, however in the industry stainless steel means something very different and are alloys that are very much softer than cutlery grades. To get specific, the stainless steels in the above are at ~25 RC, the Maraging steels are 52-56 RC.

Maraging steels are very much stronger than regular steels with a similar low carbon content, they get this way by age hardening, its the same way that the cobalt alloys develop their hardness. However cutlery steels are not low carbon, low alloy steels, and maraging steels don't compare well to the high alloy cutlery steels.

-Cliff
 
When I used to fence, Maraging foils were considered to be the best and were priced accordingly. Haven't fenced in many years. Miss it.
 
Strength does not necessarily equate with good cutting ability and good blade, a good blade is allways strong though. Ed Fowler might be best qualified to explain that further.

TLM
 
When I first heard of maraging steels, I asked myself the same question. I remember hearing someone had tried it, but that was years ago. The plot I have is for a 250 grade, aged at several different temperatures and plotted on the same graph. The maximum is about 53-54 HRc. The 350 or 400( :eek: ) grade may be able to go higher. I dont have any data in front of me. There is a relationship between tensile strength and hardness, but when comparing different alloys it is a general relationship, and may not be specific enough for comparison. Having said that, I'm going to anyway:D . At 315,000 psi, A2 has a hardness of approx. 60 HRc (reference Mission Knives website for their A2 models). Since the data I have on hand says a hardness of 53-54 for the 250,000 psi grade maraging steel, I would speculate (emphasis, I have no actual data) that the 350 or 400 grades could reach 60 or a little above. If I am correct, I think one of the advantages of the maraging steels is the greater ductility at these extraordinary strength levels. One of the disadvantages, and I would assume the reason there has not been a lot of experimentation, is the relatively long (compared to conventional steel) aging times. For the 250 grade above, the maximum hardness came after aging for over 100 hours at 800 F. There would have to be a big jump in performance to justify the power cost. Then again, we knife nuts can be talked into buying just about anything.:D :D
 
Whew! That was a long one.
I'll have to go along w/ Cliff (although lately, it seems the opposite is very popular) w/ respect to having to read into and decipher anything an advertisement has to say about a new wonder material. I had to mention it. It's one of my personal annoyances.
 
Hmm... this should probably be put asked in the Shop Talk forum. I'd be interested in hearing it from a knifemaker who's tried it.
As for why they're used for fencing blades... they are stronger (from my experience) and they also break cleanly instead of splintering into sharp edges. I'm not sure WHY it does that, but thats the main reason its used for modern sport fencing.
 
BlackRazor :

High strength would make a blade much more resistant to general damage and bending, and I do believe that, for any given size, the maraging steels represent the strongest alloys available.
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I did some searching around and while the strengths are high, they were not in excess of the high alloy cutlery steels. For example CPM-10V is has a tensile strength of about 375 kpsi, at 63 RC.

So, for a knife that will be "abused" it might be worth the tradeoff in hardness for the massive gains in toughness?
Click to expand...

Toughness is of course very different from strength, regarding resistance to fracture from impacts or ductility. The ductilities on Matweb for the maraging steels don't show outstanding ductility. Does anyone have any information on the impact toughness, ductilty and tensile strengths of the maraging steels which show them as superior to the traditional cutlery steels?


-Cliff
 
Toughness can of course be defined as tested on impact, but for practical uses almost as good is the ratio between ultimate and yield stresses, the larger the better and I think that at a given yield stress maraging steels have an edge over others (with a possible exception of bainite). If one does not need high edge keeping, maraging steels are an option.

TLM
 
Looking forward, please, excuse me for my bad English.
Also, i prefer use metric system.
Maraging steels - is one of the my main interest and i have some information about them (mainly, about Russian steels and alloys).
If you are interesting in higest hardness, you may archive one using follow steels:

Up to HRc 60 on 18% Ni, 10% Co, 4% Mo, 1.8% Ti steel (close relative to Vascomax C350 and similar steels). Using cold deformation and low temperature of aging (440-460C) you can get more, than HRc 60.

Up to HRc 63-64 on 12-13% Ni, 15-16% Co, 10-12% Mo, 0.8% Ti steel (close relative to Maraging 400 grade). Using cold deformation and low temperature of aging (440-460C) you can get HRc 65.

Up to HRc 65-66 on 8% Ni, 18% Co, 14% Mo, may be 0.8% Ti steel (close relative to Maraging 450 grade). Russian EK3 alloy, developed in in 70's, may get up to HRc 68.

And, finally, some W-Mo-Co alloys can show hardness up to HRc 70, but they have to low plasticity and impact toughness for knifemaking.

In Russia developed stainless maraging steel EP853, (11% Cr. 10% Ni, 2% Ti)/ It can be hardened up to HRc 59-60 (may be, 61).

On these days i must get 2 samples of blades, made from custom maraging steel. Estimated properties: HRc 64-65, tensile strength around of 3000 MPa, elongation approx 4%, area reduction approx 20%, impact toughness approx 0.35 MJ/m^2. First results will appear on next week.
 
Yes I would like to see that......I remember when I started my career in the '60s that maraging steels were of great interest .My thesis in school involved making a Fe/Mn maraging steel. I hadn't had any dealings with it in recent years and other than the fencing foils I knew little of it's applications today . I did a computer search and was shocked at seeing mostly websites about maraging steels in golf clubs !!! I can tell you that the originaters of maraging steels weren't thinking about golf when they developed the alloys !!
 
Alan-B said:
Looking forward, please, excuse me for my bad English.
Also, i prefer use metric system.
Maraging steels - is one of the my main interest and i have some information about them (mainly, about Russian steels and alloys).
If you are interesting in higest hardness, you may archive one using follow steels:

Up to HRc 60 on 18% Ni, 10% Co, 4% Mo, 1.8% Ti steel (close relative to Vascomax C350 and similar steels). Using cold deformation and low temperature of aging (440-460C) you can get more, than HRc 60.

Up to HRc 63-64 on 12-13% Ni, 15-16% Co, 10-12% Mo, 0.8% Ti steel (close relative to Maraging 400 grade). Using cold deformation and low temperature of aging (440-460C) you can get HRc 65.

Up to HRc 65-66 on 8% Ni, 18% Co, 14% Mo, may be 0.8% Ti steel (close relative to Maraging 450 grade). Russian EK3 alloy, developed in in 70's, may get up to HRc 68.

And, finally, some W-Mo-Co alloys can show hardness up to HRc 70, but they have to low plasticity and impact toughness for knifemaking.

In Russia developed stainless maraging steel EP853, (11% Cr. 10% Ni, 2% Ti)/ It can be hardened up to HRc 59-60 (may be, 61).

On these days i must get 2 samples of blades, made from custom maraging steel. Estimated properties: HRc 64-65, tensile strength around of 3000 MPa, elongation approx 4%, area reduction approx 20%, impact toughness approx 0.35 MJ/m^2. First results will appear on next week.
Click to expand...

That was useful info. I'll look forward to your future posting. Thanks.
 
Sorry for late post - I got 2 blades only yesterday: one medium size drop-point and one small classic poukko.
These blades are made from custom maraging steel (Fe-Ni-Co-Mo-Ti system). Steel produced from pure row materials via VIM process to small ingot. Next, material has been forged to 6x35 mm strip, than fast cool down (instead of quenching). Both blades were grinded from that strip before aging. Grindability is suitable for draft, and, not good for finish operations.
First look:
Tested hardness - HRc 64-65. Relatively good toughness and impact resistance (only preliminary “home” test results, exact values will come later). Corrosion resistance – medium, compatible to A2 steel. After aging steel may be grinded (approximately, like M2 steel) and polished to “mirror” (better, than 52100).
First unexpected moment – relatively big optimal angle of sharpening (1/2 approx 30°). Fine abrasives provide better results and may posses get relatively (but, not extremely) sharp cutting edge. This weekend will try use water stones. This weekend will test edge pretension and edge hold ability.
 
bring out the big wallet for those steels.. with all that Ni and Co it will be very expensive. good powder high speed steel can reach 5500MPa+ (66-67hrc somewhere) its also very expensive and has lots of Co, Mo, V, and sometimes W. dont know the toughness of those. i suppose the Ni in these marageing steels is what makes them tough (and the lack of carbon)
 
The maraging steels do not have iron/carbon martensite but have iron/nickel martensite which doesn't have the brittleness .
 
This weekend we plan test those blades to egge hold ability and edge retention. For comparison we have few knifes from:
D2
440C
154CM
M2 and M4
S30V
S60
1095
52100
Unfortunately, we haven't any knifes from high speed powder steels.
Main test for edge hold ability - cutting of 1" manila rope until blade can smootly cut newspaper. Main problem of modern steels - they can hold relatively sharp, fully enought for everyday using, cutting edge very long time, but, they loose razor sharpness during 10-25 cutting cycles (for stainles steels). Main reason for that - degradationof cutting edge via carbides microcheaping. High quality low alloyed carbon steels, such as 52100 can cut rope 50-100 times.
Maraging steens haven't "big", uncogerent, reiforsing phases, such as typical carbides, and, they must hold razor sharp edge very well (for example, EP853 (11% Cr, 10%Ni, 2%Mo, 2%Ti) steel used for sharp medical instruments, including microinstruments). Maraging steel get high strengh and hardness in process of "aging" - one of the kinds of precipitation hardening. Typical intermetallides, such as Ni3Ti, Fe2Mo, (Fe, Ni,Co)6Mo7 have a small dimensions (50-200A), and they are uniformly distributed in matrix.
 
Alan ,please permit me to put that into proper english. 'Carbides microchipping' not microcheaping.'Noncoherent reinforcing phase' not uncogerent reinforsing.' intermetallics [intermetallic compounds] not intermetallides....Aging is the formation of intermetallic compounds .They do the best strengthening when small and coherent and uniformly distributed.Carbides from tempering iron/carbon martensite can also be coherent in the early stages.These intermetallics are now sometimes called 'nano dispersoids' !! In the late '60s the maraging steels were 200, 250, and 300. Obviously they are a bit stonger today !
 
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