What is Alloy Self-Protection?

In short – the thermal oxides formed after Minimox® treatment have:

1. Better surface chemistry

410 stainless steel.  Recommended maximum service temperature for continuous exposure in air = 620°C (1150°F). Partially treated sample below was heated to 850°C for 30 hours.

Better surface chemistry

Untreated and oxidized 410 stainless.  Thermal oxide is thick, flaking Fe2O3. Minimox-treated and oxidized 410 stainless.  Thermal oxide is thin, adherent Cr2O3 + Cr-Mn-O spinel, even though there is no Cr or Mn in the solution.

2. Better surface structure – no flaking or protrusions

Nickel trio part 1 Nickel trio part 2 Nickel trio part 3

Minimox-treated and oxidized (100x)

Untreated and oxidized (100x) Untreated (1000x). Exposed microvoids for corrosion nucleation

Ni 600 alloy; 1000°C, 500 hours in air

  • The composition of the protective layer is primarily a function of the alloy, not the coating material. For example, the protective layer that forms on aluminum alloys is different from the protective layer that forms on stainless steels. 
  • The temperature of oxidation is set by the alloy, not by any Minimox solution requirements.