General welding questions that dont fit in TIG, MIG, Stick, or Certification etc.
Farmwelding
- Farmwelding
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Joined:Thu Mar 10, 2016 11:37 pm
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Location:Wisconsin
We just did liquid nitrogen day at school and I asked my shop teacher who was running the show if I could weld something real hot and then dunk it. He thought it would be cool but was wary due to safety. So what would something like liquid nitrogen do the the strength of a weld. Dunking welds in water makes them weaker/makes them break differently but how extreme would the damage to weld integrity be at like -300 degrees? Or would the weld just kind of snap or break off?
A student now but really want to weld everyday. Want to learn everything about everything. Want to become a knower of all and master of none.
Instagram: @farmwelding
Nick
Instagram: @farmwelding
Nick
- Otto Nobedder
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Joined:Thu Jan 06, 2011 11:40 pm
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Location:Near New Orleans
It's not the temperature difference so much as heat transfer rate. Liquid Nitrogen transfers heat slower than water because the lower vapor pressure forms a skin of vapor over the hot spots. Ever see the guy on "Outrageous Acts of Science" dump the bucket of LN2 on his head? That's why it didn't hurt him. The vapor still transfers heat, and you will quench the weld, but what you proposed to the teacher is no more dangerous than putting a room-temperature part in LN2.
I regularly "cold-shock" stainless steel welds in LN2 for the abrupt temperature change to prove the weld won't crack, and I also put hardened carbon steel in LN2 when installing bearing races in semi-trailer hubs.
I've never actually put a fresh glowing weldment in LN2, but it would be interesting. Low-carbon steels will not harden much at all, just as quenching in water. I rarely weld harder steels.
Steve
I regularly "cold-shock" stainless steel welds in LN2 for the abrupt temperature change to prove the weld won't crack, and I also put hardened carbon steel in LN2 when installing bearing races in semi-trailer hubs.
I've never actually put a fresh glowing weldment in LN2, but it would be interesting. Low-carbon steels will not harden much at all, just as quenching in water. I rarely weld harder steels.
Steve
exnailpounder
- exnailpounder
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Joined:Thu Dec 25, 2014 9:25 am
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Location:near Chicago
I use LN2 to make frozen margaritas...you guys are way overthinking this shitOtto Nobedder wrote:It's not the temperature difference so much as heat transfer rate. Liquid Nitrogen transfers heat slower than water because the lower vapor pressure forms a skin of vapor over the hot spots. Ever see the guy on "Outrageous Acts of Science" dump the bucket of LN2 on his head? That's why it didn't hurt him. The vapor still transfers heat, and you will quench the weld, but what you proposed to the teacher is no more dangerous than putting a room-temperature part in LN2.
I regularly "cold-shock" stainless steel welds in LN2 for the abrupt temperature change to prove the weld won't crack, and I also put hardened carbon steel in LN2 when installing bearing races in semi-trailer hubs.
I've never actually put a fresh glowing weldment in LN2, but it would be interesting. Low-carbon steels will not harden much at all, just as quenching in water. I rarely weld harder steels.
Steve
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