Hydrogen Trap Density
Hydrogen trap density is the number of defects in the metal that can store hydrogen. A high density slows down hydrogen diffusion and reduces risks like hot cracking.
Physikalisch-chemischer Wirkmechanismus
Hydrogen trap density refers to the number of specific lattice defects, dislocations, or precipitates per unit volume in a metal. These defects can bind hydrogen atoms reversibly or irreversibly. This affects the diffusion rate of hydrogen in the material.
Metallurgical Relevance & Welding Risks
A high hydrogen trap density can slow down hydrogen diffusion, leading to fewer hot cracks. However, too high a density can also lead to increased hydrogen pressure in the material, which under certain circumstances can cause hydrogen blisters or other defects.
Werkstattpraxis & Handlungsanweisungen
To optimize hydrogen trap density and minimize risks, it is important to carefully select the metal and welding process. Under heavy loads or high temperatures, additional control of hydrogen content should be performed. Recommended values for hydrogen trap density vary by material, but generally they should be chosen to slow hydrogen diffusion without being so high as to promote hydrogen blisters.