Carbide size will increase as carbide volume increases in general for two reasons :
-carbides form where carbides are (they pile on each other)
-in large amounts they intersect and form large "macro" carbides where a bunch of the form so close together you can end up with a chain of 5-10 carbides
This is S60V, note how the clumping is so severe in the P/M steel there are chunks of carbide bigger than the individual carbides in ATS-34 :
S60V is the one on top, ATS-34 is the one on the bottom. That dramatic difference in size of the individual carbides is due to the P/M process which basically takes a bunch of very small ingots of steel and forces them into one large ingot under very high pressure. As the carbides that form in an ingot during the initial melt are proportional to the size of the ingot, the very small ingots (the powder) of the P/M process force very small carbides which thus have to be well distributed. This is of course dependent as well on alloy as for example the carbides are still much smaller in 13C26 than in S60V even though 13C26 is an ingot steel simply because the total carbide volume is smaller in 13C26.
Thank you, I see the difference in the distribution. So the white are the carbides, and the rest is the matrix bonding all things together? Or are the color variations different carbides?
