Hydrogen-Induced Cracking Threshold Stress
Hydrogen-induced cracking threshold stress is the maximum mechanical tensile stress that can be tolerated in a material before hydrogen causes cold cracking. Exceeding this stress leads to cracks in the material.
How it works physically and chemically
Hydrogen-induced cracking threshold stress describes the maximum mechanical tensile stress at which hydrogen stays diffusible in the material without causing cold cracks. If you exceed that stress, hydrogen concentrates at the crack faces and leads to cold cracks.
Why it matters in welding and the risks
Under high mechanical loads and high hydrogen content, you can hit that threshold stress, which causes cold cracks in the material. That can seriously shorten component life and turn it into a safety hazard.
Shop practice and what to do
To avoid hitting the hydrogen-induced cracking threshold stress, steer clear of high mechanical loads during welding. You can do that by carefully picking the welding process and keeping an eye on hydrogen content with regular checks.