Hydrogen diffusion barrier
A hydrogen diffusion barrier is a coating or filler composition that blocks hydrogen in steel and reduces cracking.
Physical-Chemical Mechanism of Action
Hydrogen diffusion barriers work by creating a barrier layer that blocks the entry of hydrogen into the metal. This often happens through chemical reactions or by arranging special materials that prevent hydrogen absorption.
Metallurgical Relevance & Welding Risks
Hydrogen diffusion barriers are especially important in high-carbon steels because they are prone to hydrogen cracking. Without a diffusion barrier, hydrogen can diffuse into the metal during welding and cause cracks. This leads to shorter service life and reduced mechanical properties of the material.
Workshop Practice & Action Steps
To use hydrogen diffusion barriers effectively, coatings or additives must be applied correctly. This can be done with special welding methods like gas-shielded welding (TIG, MIG). The temperature and time of the welding process, as well as the selection of suitable coating materials, are critical. Common hydrogen diffusion barriers include silicon or titanium coatings.