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Understanding Hydrogen Induced Cold Cracking in Welds

Karsten Madsen | Apr 26, 2017

https://www.linkedin.com/pulse/understanding-hydrogen-induced-cold-cracking-welds-karsten-madsen

"Like others, I probably contributed to some weld cracking earlier in my career through ignorance about the effects of hydrogen on some metals. Problem #1 … working as a young Welder, there was usually a stash of 7018 electrodes somewhere handy saving a trip to the holding oven. Problem #2 … I'm showing my age in saying that at that time, microwave ovens had not yet showed up in cafeterias to warm up meals. No problems though as electrode ovens did a good job of heating up leftover mac 'n cheese or a can of baked beans for a warm dinner.

Adding to our ignorance, the welding rods used in both of these circumstances seemed none the worse for the wear making welds that appeared to be acceptable. So the loosely applied rules about keeping the electrodes only in dry holding ovens and used within 4 hours did not seem to justify compliance. Moisture absorbed by SMAW electrode flux coating is only one source of hydrogen entering a weld deposit. It can also exist in FCAW wires, SAW flux or come from high ambient humidity or lubricants used in other manufacturing processes. Moisture of course is hydrogen and oxygen while oils and greases are usually hydrocarbons.

My intent here is to explain in understandable terms why it is so important to control weld exposure to hydrogen for those higher strength steels that are susceptible to hydrogen induced cold cracking (HICC). I’m not a Metallurgist and I may be taking some liberties in the following explanation, but to me at least hearing the effects of HICC first hand and my analogies to explain this phenomenon seem to make sense."

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