50 HRC..... 465 custom vs 440c
50 HRC..... 465 custom vs 440c
(OP)
There are two kinds of heat hardenable steels,those that have carbon so carbides are created,like 440c and then the PH martensite steels like 17-4 or custom 465.
The carbide steels like 440c can have higher peak hardness than hardest PH steels like custom 465,but what if I heat threated and aged both steels to be 50 HRC?
They way I see it is this,at 50 HRC the 465 us significantly more corrosion resistant and tougher than 440c,the yield strenght is about the same,why would I then choose 440c or other similiar carbide steel at 50 HRC over custom 465?
Is the HRC rating missleading? Will the carbide steel at same HRC rating have improved scratch,abrasion or wear resistance?
Another comparison would be 10-2-3 Beta titanium hardened to 48 HRC vs some Stellite alloy with similiar HRC rating.The titanium is worst when it comes to galling,and Stellite is best,but for abrassion and scratch,would there be difference if they have same HRC becose Stellite got carbides and beta titanium doesnt?
The carbide steels like 440c can have higher peak hardness than hardest PH steels like custom 465,but what if I heat threated and aged both steels to be 50 HRC?
They way I see it is this,at 50 HRC the 465 us significantly more corrosion resistant and tougher than 440c,the yield strenght is about the same,why would I then choose 440c or other similiar carbide steel at 50 HRC over custom 465?
Is the HRC rating missleading? Will the carbide steel at same HRC rating have improved scratch,abrasion or wear resistance?
Another comparison would be 10-2-3 Beta titanium hardened to 48 HRC vs some Stellite alloy with similiar HRC rating.The titanium is worst when it comes to galling,and Stellite is best,but for abrassion and scratch,would there be difference if they have same HRC becose Stellite got carbides and beta titanium doesnt?





RE: 50 HRC..... 465 custom vs 440c
If you need to make a cutting device (shear or razor blade) that has corrosion resistance use 440C.
If you need strength with usable impact and fatigue properties then use C465.
Abrasion resistance is a complex function of the martial causing wear, its velocity and angle of impact.
Ti will never stand up well in wear situations.
Co alloys (even those with no carbides) have incredible resistance to galling and cavitation, and most forms of surface contact wear.
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P.E. Metallurgy, Plymouth Tube
RE: 50 HRC..... 465 custom vs 440c
Why would one 50 HRC steel cut hair and resist abrasion any different than another steel that have 50 HRC but also have carbides?
I was thinking if the materials have same HRC,their abrasion resistance must be completly identical.Do carbide steels offer better abrasion resistance even if they are same rockwell C hardness than precipitation hardened steels without carbides?
RE: 50 HRC..... 465 custom vs 440c
RE: 50 HRC..... 465 custom vs 440c
RE: 50 HRC..... 465 custom vs 440c
RE: 50 HRC..... 465 custom vs 440c
back to the topic,if I have two steel plates,both measing same HRC value but one contain carbides,will they have different scratch and abrasion resistance? Like the examples above,stellite vs 10-2-3 titanium at 48 hrc.... or custom 465 vs 440c at 50 hrc,do carbide containing alloys have higher scratch resistance than non-carbide alloys even through they can measure same rockwell c value?
RE: 50 HRC..... 465 custom vs 440c
Yes.
You can do your own information search.
RE: 50 HRC..... 465 custom vs 440c
Thus, hardness cannot be considered to be a true measure of wear resistance.
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.
RE: 50 HRC..... 465 custom vs 440c
Wet or dry, what size is the abrasive, how hard is the abrasive, how fast is it moving, what is the angle of impingement
All of these matter a lot.
Superficial hardness can only be used when comparing similar material for wear resistance.
When you change alloy type it is meaningless.
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P.E. Metallurgy, Plymouth Tube
RE: 50 HRC..... 465 custom vs 440c
If I get 50HRC from carbides,is it superior type of hardness than if I get 50 HRC from martenistic heat threatment or cold working? Is there anything special about carbide containing steels or alloys that isnt revelead by HRC test? If I need part to be scratch resistant,why would I go with carbide steel if I can cold work or age another steel without carbides to the same 50 hrc,wouldnt it be roughly equaly scratch resistant?
The type of abrasion I mean is when you for example take piece of metal,like screw and drag it with certain pressure across polished plate.If one plate is 440C and other custom 465,and they are both aged and heat threated so they both measure 50 HRC,would there be any noticable difference in how they are scratched just becose 440C is 50hrc with carbides and 465 is 50 hrc without carbides?
RE: 50 HRC..... 465 custom vs 440c
And scratch resistance bears little relationship to general abrasion resistance.
I know of now such general relationship based on hardening mechanism.
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P.E. Metallurgy, Plymouth Tube
RE: 50 HRC..... 465 custom vs 440c
is generally yes when these different alloys are being used in the same application under the same conditions. It is easiest to explain this using high speed steels as the example, since these types of steel alloys are often used in applications where their excellent abrasion resistance and high attainable hardness are requirements.
The wear resistance of high-speed steels is strongly dependent on the amount, type, size, shape, and distribution of the alloy carbides that are present in the microstructure. The function that these carbides serve can be understood through the use of an analogy. Consider the appearance and function of a cobblestone road: The alloy carbides that appear in the tool steel microstructure serve a purpose that is comparable to the function of the wear-resistant cobblestones in the road — they provide a very hard contact surface area that is extremely resistant to abrasion and wear. And the mortar that holds the cobblestones together is much like the steel matrix that holds the carbides together in the alloy. Many different types of carbides can be formed, depending on the chemical composition of the alloy. Carbide types are normally identified in a basic sense by their chemical composition. For example, in the microstructure of vanadium carbide, there is a one-to-one ratio of vanadium atoms to carbon atoms, to form the carbide phase VC. This one-to-one ratio is usually expressed in a generalized way by the expression MC, where M represents the alloying element of interest (in this example, vanadium) and C represents carbon. Many other combinations are also possible. Cementite, the carbide typically found in plain carbon and low-alloy carbon steels, is an M3C-type carbide consisting of three atoms of iron and one atom of carbon to form Fe3C (the text editor will not permit me to make the 3 a subscript to Fe, but that is what it is supposed to be). Steels that contain appreciable amounts of manganese also form an M3C type of carbide, namely Mn3C. Manganese and iron have very similar atomic weights, and both of these carbides are typically found in combination. But more complex carbides are also represented using this terminology. The M3C carbide can be thought of as having a chemical formula of (Fe+X)3C, where X refers to different combinations of manganese as well as the four major alloying elements, Cr, V, W, and Mo. The precipitated metal carbides such as MC and M2C can attain very high hardness, and they contribute significantly to the wear resistance of high speed steels that are alloyed to contain large volume fractions of these particular carbides. Depending on the alloy composition, many of these steels usually contain more than one type of carbide. For example, in annealed M4 high-speed steel the carbides are a mixture of types MC, M23C6 and M6C. In practically any given high speed steel, the wear resistance depends on the hardness of the steel. Higher hardness, however achieved, is an aim when highly abrasive cutting conditions will be encountered. For the ultimate in wear resistance, carbon content can be increased simultaneously with vanadium content to form a greater volume percent of extremely hard vanadium carbides. Steels T15, M3 (class 2), M4, and M48 belong in this category, and all exhibit extremely high wear resistance.
Maui
RE: 50 HRC..... 465 custom vs 440c
RE: 50 HRC..... 465 custom vs 440c
A great explanation Maui.
"Even,if you are a minority of one, truth is the truth."
Mahatma Gandhi.
RE: 50 HRC..... 465 custom vs 440c
RE: 50 HRC..... 465 custom vs 440c
In this case the wear can attack the mortar and undercut the binding holing the stones in place.
This is why size, hardness, and angle of attack are so important.
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P.E. Metallurgy, Plymouth Tube
RE: 50 HRC..... 465 custom vs 440c
you say it is generaly true that carbide containing steels/alloys outperform other non-carbide steels/alloys at same HRC,you didnt explain why.You explained very good the carbide stuff,but not why,at same hrc,why would carbide containing steel outperform non-carbide steel.
You say the carbides are like hard cobbles and the steel matrix is like the mortat.I wonder,why even bother with carbides/cobbles,why not just use super hard mortar/steel matrix?
10-2-3 titanium can go up to 48 hrc
custom 465 goes to 50 hrc
tribaloy T-800 = 62 hrc
none of these have any carbides.I know the tool steels have higher HRC like 65 and in that range non-carbide steel is not an option,but in the lower hardness range,what is so special about carbides that I would take them over non-carbide alloy/steel if they measure exactly same in HRC test apart from other parameters that doesnt have anything to do with hardness like galling and corrosion resistance.
RE: 50 HRC..... 465 custom vs 440c
It is safe to say a higher hardness generally leads to a better wear resistance, when the materials belong to one family with similar microstructures.
RE: 50 HRC..... 465 custom vs 440c
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa....
RE: 50 HRC..... 465 custom vs 440c
The only thing that is clear is that if you have two alloys that share a general composition and hardening mechanism, then the harder one will probably have better wear resistance.
But across a range of media and environments there is no way to look at a group of alloys and predict abrasive wear resistance.
In some cases carbides help, in others intermetallic precipitates are plenty good.
The only generalities are that Al and Ti alloy have poor wear resistance at any hardness, and that Co based alloys always overachieve.
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P.E. Metallurgy, Plymouth Tube
RE: 50 HRC..... 465 custom vs 440c
RE: 50 HRC..... 465 custom vs 440c
Because the carbides can go up to really high hardness such as 2200HV for WC used in a metal (Ni) matrix with 40 HRC that outperforms quenched and tempered steel with 52 HRC (for example).
RE: 50 HRC..... 465 custom vs 440c
The binder allows for parts of useful size to be built. For small diameter wire you can make draw dies from diamond or single carbide pieces, but they have to held tightly in compression.
fapper, it has to do with slip planes and strain hardening, which go back to the HCP structure.
For example even Co alloys without carbides are very resistant to cavitation damage, even better than some very hard materials that will fail in fatigue or fracture.
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P.E. Metallurgy, Plymouth Tube
RE: 50 HRC..... 465 custom vs 440c
You asked,
Because the hardness of the steel matrix is generally limited to about 60 HRC for most of the higher carbon steel alloys. But the carbides themselves are much harder than this with values that can range from about 64 HRC for cememtite to 84 HRC for vanadium carbide. Carbides are very hard and wear resistant particles, but they are brittle. The steel matrix in which they are embedded is softer than the carbide particles, but is much more ductile. This is the reason why this combination is so effective in providing good wear resistance. The carbides are held in place by the steel matrix and they provide a hard and wear resistant surface to resist abrasion. The Rockwell C hardness that you would obtain by making a direct hardness measurement on a sample piece of one of these steel alloys represents an average hardness value of the carbides and the steel matrix. When you are referring to hardness readings in your previous posts it does not appear as though you understood this. Does this explanation make it clear?
Maui
RE: 50 HRC..... 465 custom vs 440c