Most people have no idea what is used in making a knife. "Steel!" they say. This is a short blog which goes over the key ingredients and why (or why not) you add these ingredients. There are many more but these are the elements most commonly used for steel used in knife making.
1. Iron (Fe)
When knives were first made knives were made with Iron and even today it remains the main ingredient. Most knives in modern days are made with ~80% iron with are elements thrown into the broth to make the "Perfect knife." We fiddle with components like Carbon (C), Chromium (Cr), Cobalt (Co), Molybdenum (Mo), Nickel (Ni), Vanadium (V), and many more (all add one lever and reduce another). As we learn over time there is no such thing as a perfect knife - just the best knife for certain use.
2. Carbon (C)
Carbon is the 4th most abundant ingredient on planet earth. It is an ingredient that can be compacted and released and the core of the debate regarding climate change. When you are carbon to your blade you are putting carbon away and saving the world for another day ;) (you'd need a lot of knives to house daily carbon releases).
Pros - On more serious notes carbon is primarily used to make knives (your steel) harder. The more carbon, the harder the edge. It's the main ingredient that hardens the blade in the process. Classic western knives (wusthof, victorinox etc) will have around ) 0.5%. Japanese knives will have carbon as high as 3%. There is no correct answer. The more carbon you had the harder it becomes BUT the more carbon you add the more likely your knife is to dent or break and the more likely it is to rust. There is nothing perfect - it's a balancing act.
3. Chromium (Cr)
If we making a "Stainless steel" (there is no such thing) and avoid rusting of our blade we need to add Chromium.Depending on where you are on planet earth (it changes by countries) you legally need 11-12%+ chromium to meet the amount that allows you to call your steel "Stainless." To be clear there is no steel that is stainless. Add enough acid and stainless steel will rust. The question is "How stainless is this steel"? If you want it to be more stainless add more chromium BUT the hardness of the steel will go down. There is no perfect answer - it's a balancing act.
That's enough for most but if you want to know about a few more spices (elements) that are often added to steel keep reading.
4. Nickel (N)
Nickel is cool :) Like all elements it has pros and cons.
Nickel is the 5th most abundant element on planet earth. When using in knife making, Nickel does not rust and can improve a knives defence of corrosion. It's shiny and for Damascus finishes can improve the contrast in layers. It has high ductility helping blade shaping easier. That said it can reduce hardness when over imposed. Nickel can also shield magnetic fields (AKA your knife doesn't stick to wall magents very well anymore). It's
There is no perfect amount - it's a balancing act.
5. Molybendum (Mo)
A carbide former, prevents brittleness, and maintains the steel's strength at high temperatures. It can also improve machinability and resistance to corrosion. It is not a core ingredient (like iron, carbon and chromium but can be used to assist). If overused the knife becomes brittle and breakable.
There is nothing perfect - it's a balancing act.
6. Vanadium (V)
Vanadium is added to improve hardening of the steel whilst improving wear resistance. It is added to the existing brew and does not do this alone.
*(If you wish to know more let me know and I'll write a bit more another day :))