7CR17MoV, it's 440A modified which contains more elements vanadium, the benefits of Vanadium (V) • Increases strength, wear resistance, and increases toughness the recommended hardness about 55/57 HRC.
9Cr13MoVCo, 9Cr14MoV. Chinese made steels that are similar to 440 but with a higher carbon, cobalt and vanadium content to add more strength to the blade. Uses include high end barber scissors, hunting knives etc.
Carbon Steel Vs Stainless Steel Knives:
Carbon steel is a popular choice for rough use knives. Carbon steel tends to be much tougher and much more durable, and easier to sharpen than stainless steel. They lack the chromium content of stainless steel, making them susceptible to corrosion. Thus proper care such as never let sit in water or store without coating with a thin layer of oil.
Carbon steels have less carbon than typical stainless steels do, but it is the main alloy element. They are more homogeneous than stainless and other high alloy steels, having carbide only in very small inclusions in the iron. The bulk material is harder than stainless, allowing them to hold a sharper and more acute edge without bending over in contact with hard materials. But they dull by abrasion quicker because they lack hard inclusions to take the friction. This also makes them quicker to sharpen. Carbon steel is well known to take a sharper edge than stainless.
Stainless steel generally has a higher chromium content than Carbon Steel and thus makes it more resistant to rust, staining and corrosion. This also keeps the knife looking new and aesthetically appealing to the majority of the population longer. Stainless Steel is generally not as hard as Carbon steel and it makes them more durable (less susceptible to edge chipping) These knives do not get as sharp as Carbon Steel nor does the edge last as long.
As with everything in life there is no one perfect solution. So which steel is best for you? The answer to that question depends on what features are really important to you and what negatives you are willing to deal with