I’ve used the All-Clad Emerilware line for years (7), I love my cookware. I’ve slowly been supplementing the basic set with a few choice vanity pieces here and there. I think it’s a great set for aspiring cook and so I gave my sister and her husband an identical set as a wedding present.
Something strange happened though, I stopped by to see her at work one day and she told me this bizarre story of how one of her pans had melted, the bottom plate fell off and the liquid metal damaged her floor.
This made no sense to me. If it were a gas range, I suppose, if the pot had boiled dry it would be possible for this to occur. However, it was a standard (non-inductive) smooth top electric range. These have thermostat (there’s a more accurate term for this, but I don’t know it offhand) that shut the burners on and off as they reach the appropriate temperature. Even at the highest setting, this is nowhere near the melting point of the aluminum core (1220F if you need to know) of the stainless steel set. So what happened?
My husband who is an electrical engineer in the steel industry, finally figured out a potential reason for this freak occurrence. I’ll share his reason and then translate it from engineer1 to English.
The basic premise of electric range operation is to pass current through a resistive conductor thereby transforming electrical energy to heat energy. Another effect produced by this is a rapidly expanding and collapsing magnetic field. This is the source of the magnetic lines of flux, which interact with the non-ferrous metal layer in the pan through the Lorenz effect, to produce Eddy Currents (Note: You may be thinking that Hysteresis losses would play a big part in this, but you’d be wrong). It may be this centralized inductive build up of heat due to the excessive eddy currents in the aluminium layer that is causing temperaturess to exceed 1220 degrees fahrenheit and the eventual catostrophic failure of the cooking vessel.
Aluminum is a nonferrous metal, meaning it cannot interact with magnets, but it can conduct a current, this current can create a magnetic field and sometimes the electric current in the burner can create a magnetic field. And once in a while these magnetic fields can interact. Have you seen the newer ranges that use magnetic induction to heat pots while the surface of the range stays cool? This freak accident happened due to the same principle, only it happened in an uncontrolled way causing the temperature to surpass the melting point of the aluminum.
*If you’ve been with me through the edits, just hang tight, I’ll get it right one of these times. I can see it in my head, it’s just refusing to come out in a semi-articulate manner.*
Thankfully no one was hurt. As this is just a freak, unintended interaction between the burner and the core of the pan, I don’t know that it could have been prevented.
I use these pots and pans every day, but I am a little more careful about letting the kids wander underfoot in the kitchen.
1 Why yes, we are fun at parties, why do you ask?