Internal oxidation
Subsurface oxidation is unwanted oxidation of metal alloys below the surface during annealing or hardening. It can lead to damage and loss of strength.
Physicochemical Mechanism of Action
Skin oxidation happens when metal alloys come into contact with oxygen while they are hot. This can be from air or moisture. The oxidation forms a thin layer on the surface and below it.
Metallurgical Relevance & Welding Risks
Skin oxidation can damage the workpiece structure, causing loss of strength and toughness. It can also lead to corrosion and other metallic problems that reduce the metal's service life.
Workshop Practice & Procedures
To prevent skin oxidation, clean metal parts thoroughly before hardening. Use protective agents like shielding gases or coatings. Keep the environment dry and clean. During hardening, stick to the exact temperature and time to avoid oxidation.