Which practices minimize hydrogen-induced cracking in welding?

• A. Increase hydrogen content in electrode coating and keep interpass temperatures high.
• B. Use dry hydrogen-free electrodes, preheat, maintain proper interpass temps, store filler metals properly, and bake if required.
• C. Use wet electrodes, skip preheat to speed up, store filler metals in a humid area, and avoid baking.
• D. Apply rapid cooling after welding to trap hydrogen and relieve stresses.

Answer: (B)

Hydrogen-induced cracking happens when hydrogen from moisture or moisture-containing materials gets into the weld and, if the metal cools too quickly or stays too hard, hydrogen can’t diffuse out, forming cracks. The best way to prevent this is to minimize hydrogen sources and give hydrogen a chance to escape during heating and cooling.

Using dry, low-hydrogen electrodes is crucial because their coating releases far less hydrogen into the weld puddle. Keeping the electrode in a dry, controlled environment and baking it if required ensures any absorbed moisture is removed before welding.

Preheating the joint raises the metal temperature before welding starts, which slows hydrogen diffusion into the steel during solidification and gives trapped hydrogen a better chance to diffuse out as the weld cools. Maintaining proper interpass temperatures keeps the weld zone from becoming excessively hard and helps hydrogen diffuse between passes rather than being locked in by a rapid, brittle microstructure.

Storing filler metals properly keeps them dry, so they don’t contribute moisture-derived hydrogen to the weld. Baking filler metals when specified further removes any absorbed moisture, reducing hydrogen availability during welding.

Choices that rely on wet electrodes, skipping preheat, letting moisture stay in filler metals, or cooling the weld rapidly all increase hydrogen introduction or trap it in the metal, which raises the risk of hydrogen-induced cracking.