Tag Archives: welding preheat

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5 Methods to Determine Preheat Temperature

Preheat is used when a base material, due to its chemical composition, thickness or level or restraint, is susceptible to cold cracking (hydrogen induced cracking).  Knowing what temperature to preheat your base metal is sometimes a complicated matter.  You may hear people say “preheat to 300F to be safe.”  The reality is that 300F may […]

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Steps to determine if welding preheat can be eliminated?

Testing the effects of preheat in small parts and assuming it will be the same on large sections is a mistake.

As discussed in our previous article, and many times in the last 50 or so, preheat is necessary in steel welding to control the cooling rate.  More specifically, preheat is used to slow the cooling rate down in order to prevent excessive hardness in the heat affected zone (HAZ) which  can lead to cracking.   Before […]