Heat tint
Heat tint is a thin oxide layer on the material surface that forms at high temperature and in the presence of oxygen. It can impair the corrosion protection of corrosion-resistant steels.
Physical-Chemical Mechanism of Action
Heat tint forms through the reaction of oxygen with the material in the weld zone. This process is accelerated when high temperatures and oxygen are present.
Metallurgical Relevance & Risks in Welding
Heat tint can impair the corrosion protection of corrosion-resistant steels. It can also lead to increased sensitization and cracking if not properly removed.
Workshop Practice & Instructions
To avoid or minimize heat tint, the following measures should be taken:
• Use a suitable shielding gas atmosphere (e.g., argon) during welding.
• Cool the material quickly and evenly after welding to prevent the growth of the heat tint layer.
• Remove heat tint by polishing or chemical cleaning after welding.