The simplest steel on the list is CruForgeV, a steel designed by Crucible specifically for those who forge. Steels for forging have a different set of requirements than tool steels or air hardening steels. They obviously need to be easy to forge, and respond well to thermal cycles with typically short hold times and often variation in temperature due to the limitations in equipment and doing things by eye. While Japanese bladesmiths have enjoyed alloys designed for them, such as the White and Blue steels, Americans have typically stuck with simple carbon steels (ie 10XX series), alloy steels (15N20, 52100), and simple tool steels (O1, L6), which were designed for other purposes, though of course can make quite good knives.
These steels offer some range of properties, such as the ability of O1 to be oil hardened, removing the need for aggressive water or brine quenching. However, they are typically in the category of medium to high toughness and low wear resistance, because of the small volume of small carbides. They are loved by users for their ease in sharpening and easily polished, hair-popping edges due to these small carbides, but are somewhat limited in terms of corrosion resistance and wear resistance.
Japanese bladesmiths have the option of the Blue steels which have alloy additions, particularly Tungsten, to increase wear resistance, and also have the ability of purchasing stainless-clad steel for improved corrosion resistance, at least away from the edge. CruForge V offers some similar characteristics. Crucible made a small but significant Vanadium addition which thermodynamic software predicts will lead to approximately 1% vanadium carbide along with another 1-3% cementite (iron carbide) which leads to a modest increase in wear resistance while still retaining the properties forgers like, including ease of forging, good toughness, and ease in sharpening. Vanadium carbide is the hardest of all the typical steel carbides, and therefore has the greatest improvement in wear resistance for a given amount; however, this can also lead to a decrease in sharpening, particularly because vanadium carbide is harder than most sharpening stones. With a relatively small amount of 1% by volume in the heat treated steel, the amount is small enough that ease of sharpening is maintained. This small amount of vanadium carbide also means that the carbide size is still exceptionally small like other carbon and alloy steels, so its carbide size is much smaller than the typically higher-alloyed PM tool steels.
In the end, CruForge V has a good combination of moderately low wear resistance, good toughness, and good ease of sharpening. It should have a better balance of toughness and wear resistance than the Blue steels, because it has somewhat lower overall carbide volume (higher toughness), but replaces some of those carbides with the very hard vanadium carbide (improved wear resistance). This makes it a good alternative to Blue steels for American bladesmiths. With Dad's ability to clad CruForgeV, improved corrosion resistance or toughness of the overall blade can also be achieved, depending on the chosen clad material.
