Stainless steel alloy effects, information from me (Trond) Victorinox collected and researched
for my old page + new knowledge gathered. Information from Victorinox emails, Victorinox Manuals and discussions:
The Hardening process starts
with high temperature in protective gas atmosphere. This process is what affects the chemical composition that the martensitic stainless steel composition have. The component Carbon 0, 3 %-1, 0 % determines hardness and influence the sharpness. Increased carbon
content reduces corrosion resistance. Less Carbon gives better rust resistance but edge holding abilities become less. It is the Chromium component that makes the alloy or steel stainless by having content with at least 12 %. For a note I can tell that in
martensitic stainless steel today Nitrogen N is used sometimes to replace carbon and this also helps for corrosion resistance. The Chromium in the alloy creates a passive surface layer of Chromium oxide that protects the steel from corrosion. If a stainless steel got a high Carbon content the Molybdenum can improve the corrosion resistance caused by the high carbon content. High Chromium content provides better corrosion resistance but reduces
the hardness while molybdenum makes it harder. Nickel chromium steels are extremely resistant to corrosion, rust and acids but easily bent and with a very low edge holding ability.
Ok, about the note above with Nitrogen and Carbon
The use of Nitrogen can partially replace Carbon and help for the corrosion resistance as well.
I found an
article in a magazine some ago mentioning that steel producers reduce the Nickel content in steel to increase the wear resistance of the edge and reduce brittleness. I am not sure how this is to be intrepid. Victorinox mention in their manual about nickel
chromium steel. Well the amount of nickel in the 1.4110 steel as example I cannot find specs that show any amount of nickel so it must be low? It is very interesting. The thing with the steel used by Victorinox is the very high corrosion resistance. It
only requires basic maintenance with hand warm water and some oil for the friction parts. I use some soap on SAKs when I want to clean them well. I rinse very much after that, wipe of and use some oil. During use some mention the greyish substance that can
form during use and it is most likely because the SAK is brand new and during this time that can be days or weeks this may happen. It is therefore smart to just clean it after it’s been used on substances, foods and for outdoors tasks. I am always very
interested in things like this. Some oils can dissolve dirt and things that can cause this color. It is in my opinion not rust because it is removed by basic cleaning. It is so that stainless steels in permanent dampness, salty environments, humidity and from
aggressive substances can rust, corrode and get discolorations.
From what i know so far and from
people i have discussed with say the oils that can be used for SAKs are:
The Victorinox multi-tool oil ( the best and food safe )
Medicinal grade white oil (mineral oil) ( one of the best and food safe to a degree)
WD-40 ( very well for cleaning, oil and mainteance but got scent )
Ballistol ( very well for cleaning, oil and mainteance but got scent )
Vegetable oils (many use this, i never use this and
it is not well against ageing)
Avoid oils that harden becasue these will damage the SAKs, damage aluminum and cause failure for the
It is smart after you have cleaned the SAKs to let them dry out well before
oil. Some oils dissolve substances and dirt on the surface of materials and it is not to worry about. Stainless steel reacts to oxygen and develops a chromium oxide film, aluminum reacts to oxygen and develops a passive oxide film that prevents further changes
to the surface, if anodized the surface by a chemical or certain anodizing processes creates a thicker and harder film. This protects the aluminum from further changes. Aluminum protects itself by naturally create in contact with oxygen this film too but not
as secure as an anodized surface. Brass reacts with air and creates patina and this patina can dissolve by oils and not to worry about. Brass can also react differently to humidity, chemicals and air. Friction between metals and construction can cause color
on the surface and oils and easily removed by cleaning.