Hardness: The ability of a material to resist permanent deformation. Specifically: resistance to scraping and abrasion.
Scratch hardness: Compare the hardness of different materials. The use of softer materials to draw harder materials will not make traces, or there will be no obvious traces; On the contrary, there can be obvious scratches. Example: the same material stainless steel wire ball and stainless steel products brush each other. Although the same material, but the two processing processes are different. The steel ball is processed through severe cold deformation and has a higher hardness. So with the steel ball repeatedly scrubbed, stainless steel surface will appear scratches.
Solution: scrub stainless steel products with softer materials or use anti-scratch(high hardness) stainless steel products.
Reasons for stainless steel rust resistance: The rust resistance of stainless steel is mainly due to the formation of chrome-rich oxide film(passivation film) on the surface of steel.
The chrome-rich oxide film(passivation film) on the surface of stainless steel forms extremely fast. When a stainless steel metal product is scratched, a new passivation film is quickly formed in the air for rust-free repair, but stainless steel with scratches. The surface corrosion resistance decreases(defect factor rather than material factor).
Stainless steel materials that meet the National food safety standards GB 4806.9-2016 "Metal Materials and Products for Food Contact" will not affect health due to scratches on the surface of stainless steel. This standard carries out the heavy metal ion dissolution experiment of stainless steel in a harsh corrosive environment. Compared with the corrosion resistance caused by the scratches, it is not enough to cause heavy metal ion migration.
Long-acting antimicrobial properties of antimicrobial stainless steel: The antimicrobial principle of alloyed antimicrobial stainless steel is to sterilize with trace copper ions that are uniformly dispersed and continuously released by the antibacterial phase containing copper in the matrix, and their antimicrobial effects will not disappear.
Because chlorine is used in tap water for disinfection, the water contains chloride ions, leaving some calcium ions, magnesium ions, potassium ions, and some sulfates and other trace minerals when disinfecting. After the dishes are washed, they inevitably leave water beads. When the dishes are sterilized by the high temperature disinfection cabinet, the water droplets on the dishes in the high temperature process evaporate and retain metal ions to form a "salt bar", which leaves water stains.