Thermal Stress – severe overheating or sudden changes in temperature. Material Stress – Stress tolerance levels must be adhered to when using cast iron. If the material is used incorrectly, exceeding its capability, this will place too much stress on the cast iron, causing it to crack or break apart.
We know that in a cast iron it has some amount of carbon. Because of this added carbon which makes the material more stronger, harder. But this comes with a major disadvantage of brittleness, because of which they tend to crack. Cast iron skillets are stable at high temperature.
Cast iron famously seasons itself with cooking because the oils bake onto the pan. But over-enthusiastic scrubbing, acidic foods, or excessive heat can break down that seasoning. It's a good idea to reseason your skillet a couple of times a year or any time you notice the surface of your pan drying up or rusting.
Stick/MMA:
Stick is arguably the best and most popular process when it comes to crack repair of common cast irons, especially where users have limited equipment and/or experience. Cast iron rods/electrodes are readily available in small qtys (or 'handy packs') which is ideal for one-off jobs.
Black Residue
There can be residue from the seasoning that may come off your seasoned cookware. The residue is not harmful in any way and will decrease as the cookware is used over time.
Eggs fall into the category of sticky foods that are not ideal for cast iron skillets that haven't built up their seasoning yet. While cast iron can become non-stick with sufficient use over time, a newer skillet will almost certainly cause your eggs to stick to its porous surface.
The more you use a rusted pan, the more iron you'll consume in your food. It's best to avoid cooking with a rusty cast iron pan. If it's reached the point of corrosion or deep rust, throw it away rather than risk your and your family's health.
You should only need to fully re-season your cast-iron cookware one to two times a year, but you may also want to give it some extra seasoning love anytime you cook something that requires a heavy-duty cleaning.
If a crack appears in your cast iron pan, it's time to ditch it.
The disadvantages of cast iron
One of the main drawbacks of cast iron pans is their weight. Cast iron is significantly heavier than other types of cookware, which can make handling and maneuvering them more challenging, especially for individuals with physical limitations.
Caring for Cast Iron
With soap if it needs it. Scrubbing with the rougher side of a sponge if it needs that to remove food particles. Don't use steel wool, and do dry it completely. Then, put another tiny bit of oil in and rub it all over, wipe it away, and put it over a burner for a few minutes.
But, unlike cast iron, carbon steel pans are perfect for cooking eggs, omelets and crepes, as well as fish, which is notorious for sticking. The smoother surface plus the seasoning are what makes carbon steel so slippery. And because it's lighter, you can easily use it for sautéeing.
Common cooking oils like olive oil will gradually produce seasoning, but won't be as effective as grapeseed oil. Canola, other vegetable oils, and shortening are a little better.
Two words: heat & oil.
The most common reason food sticks to cast iron is because the pan is simply too hot. Because cast iron retains heat much better than other types of cookware, you generally don't need to use as high of a heat setting as you normally would with stainless steel or aluminum cookware.
Cast iron is a big hunk of iron, after all. Too much exposure to water will cause it to rust. You can still salvage a rusted pan by scrubbing and re-seasoning it, but it's more of a pain than just wiping the skillet dry every time you use it.
Cast iron is harder, more brittle, and less malleable than wrought iron. It cannot be bent, stretched, or hammered into shape, since its weak tensile strength means that it will fracture before it bends or distorts. It does, however, feature good compression strength.
Cast iron shines when it comes to high-heat cooking, like searing steaks or charring vegetables, but it goes beyond that—you can use cast iron to sauté, bake bread, or even or make a table-worthy dessert.
Cooking with a cast iron pan that has a little bit of surface rust on it isn't likely to hurt you. If your pan is seriously rusty or has visible rust flakes, you shouldn't cook with it until the rust is removed and the pan is washed and re-seasoned.
The Lodge 10.25-Inch Pre-Seasoned Cast Iron Skillet has proven time and time again to be the best overall cast iron due to its unrivaled consistent heating at a stellar price.
Over-cleaning your cast iron pan is unnecessary and will only stand to damage your seasoning.