One of my sauce pans has “bubbled” on the bottom. I can only assume some type of “separation” took place. It still works and I use it on a regular basis. I didn’t pay a lot for it and don’t expect it to last my lifetime. I’ll replace it one day.
I mean. Anything can happen just like stainless steel-aluminum cookware can separate too, but I always thought of these are extremely rare (but real) incidents. It is like any Amazon reviews, there are always about 2-5% of the reviews indicate bad experience with the products. An All-Clad pan wrapped for them for example.
Likely some contaminant between the sheetstock, that prevented consistent bonding.
Yes, but you’ve already ID’d the relative thinness of the lid’s copper layer. I believe this cover deformed the way it did because the 0.2mm SS layer was more resistant to deformation than the 1mm soft copper. It would likely be the other way around if the ratio was 2.3:0.2, but the same result overall.
Mac Kohler has posted photos of delam bimetal pans. It is a very rare occurrence. The photos I’ve seen almost always show the failures at the inside shoulder, FWIW.