The chemical reaction between atmosphere and metal

(1) The chemical reaction between atmosphere and steel

1. Oxidation

2Fe+O2→2FeO

Fe+H2O→FeO+H2

FeC+CO2→Fe+2CO

2. Restore

FeO+H2→Fe+H2O FeO+CO→Fe+O2

3. Carburizing

2CO→[C]+CO2

CH4→[C]+2H2

Fe+[C]→FeC

4. Nitriding

2NH3→2[N]+3H2

Fe+[N]→FeN

(2) The effect of various atmospheres on metals

Nitrogen: will react with Cr, CO, Al.Ti at ≥1000℃

Hydrogen: can reduce copper, nickel, iron and tungsten. When the water content in hydrogen reaches 0.2-0.3%, it will decarburize steel

Water: When ≥800℃, it will oxidize and decarburize iron and steel without reacting with copper

Carbon monoxide: its reducibility is similar to hydrogen, which can carburize steel

(3). The influence of various atmospheres on resistor components

Nickel chromium wire, iron chromium aluminum: sulfur-containing atmosphere is harmful to resistance wire