Successful welding of HSLA steels requires careful control of hydrogen, so what should be done?

• A. Increase welding speed
• B. Use filler metals that produce a low hydrogen deposit
• C. Ignore hydrogen content
• D. Use high hydrogen deposit fillers

Answer: (B)

Hydrogen in the weld can cause cracking in HSLA steels, especially in the weld metal and heat-affected zone when there’s tensile stress. The most direct way to prevent that is to choose filler metals that produce a low hydrogen deposit, which keeps the hydrogen content in the weld metal, and thus the driving force for hydrogen cracking, as low as possible. Low-hydrogen consumables (and keeping moisture out of the weld consumables) are designed to minimize hydrogen pickup during welding. While heat input management (like preheating) can help reduce hydrogen diffusion, the key action here is selecting a filler metal that yields a low hydrogen deposit. Using fillers that introduce more hydrogen or overlooking hydrogen content increases the risk of cracking.