The Magnetic Pull Of Cast Iron Pans: Unlocking Their Secret Powers

Cast iron pans are magnetic, making them a great option for induction cooking. Induction cooktops use magnetic fields to heat the pan, so the cookware must contain ferrous, conductive metals. Cast iron is a type of iron-carbon alloy that inherits the magnetism of iron due to its high iron content. Therefore, cast iron pans are attracted to magnets and can be used on induction stovetops.

Induction cooktops

However, there are a few things to keep in mind when considering induction cooktops. Firstly, they might require you to replace your cookware, as they only work with certain types of metal. Secondly, cooking with induction feels very different from cooking with gas, and some people prefer the immediate visual feedback of a gas flame. Induction cooktops can also be more expensive than conventional electric models, and they may emit unfamiliar buzzing or humming sounds, especially at higher settings.

Cast iron's composition

Cast iron is an alloy of iron and carbon, with carbon content ranging from 1.7% to 4.5%. It also contains small amounts of silicon, sulphur, manganese, and phosphorus. The presence of carbon in cast iron can be in two forms: free carbon or graphite, and combined carbon or cementite.

The amount of carbon and silicon content in cast iron is adjusted to the desired levels, which can be anywhere from 2% to 3.5% and 1% to 3%, respectively. The combination of high carbon content and the presence of silicon gives cast iron its excellent castability.

Cast iron tends to be brittle, except for malleable cast irons. It has a relatively low melting point, good fluidity, castability, excellent machinability, resistance to deformation, and wear resistance.

There are several types of cast iron, including:

• Grey cast iron, which is the most common type and is characterised by its graphitic microstructure, giving it a grey appearance when fractured. It has less tensile strength and shock resistance than steel but comparable compressive strength.
• White cast iron, which has a lower silicon content and faster cooling rate, causing carbon to precipitate out as cementite rather than graphite. This results in a brittle material with high hardness and abrasion resistance.
• Malleable cast iron, which starts as white cast iron and is then heat-treated to convert the carbon in iron carbide into graphite and ferrite. This process results in a more ductile material with properties similar to mild steel.
• Ductile or nodular cast iron, which contains magnesium, causing the graphite to form in a spheroid shape. This type of cast iron is impact-resistant and deforms on impact rather than shattering.
• Compacted graphite iron, which has a graphite structure and properties that are a blend of grey and white cast iron. It has higher tensile strength and improved ductility compared to grey iron.

The mechanical properties of cast iron, such as hardness, toughness, ductility, elasticity, and tensile strength, determine its suitability for different applications.

Magnetism in metals

Cast iron pans are magnetic, and this property makes them ideal for use on induction cookers. Induction cookers use magnetic fields to generate heat, so cookware must be made of ferrous metals to be compatible with this type of stove. Cast iron pans are a great option for induction cooking as they are naturally magnetic and efficiently conduct heat.

There are three elemental metals that exhibit magnetism: iron, cobalt, and nickel. These elements are essential components of all magnetic materials. Compounds and alloys containing these elements can also be magnetic, such as many types of stainless steel. Metals that can be magnetized are described as "ferromagnetic". While some ferromagnetic metals are naturally magnetic, others need to be magnetized to become magnets. The process of magnetization involves realigning the crystalline structure of the atoms within the metal so that they all face the same direction.

Magnets have a wide range of applications, from temporary mounting and data storage to electric guitar pickups and Maglev trains. They can also be used to generate electricity when used with a conductive wire. The development of modern high-strength magnets in the 20th century has led to their widespread use in various everyday devices, from wristwatches and iPads to hybrid vehicle motors.

Cast iron's versatility

Cast iron is a highly versatile material with a range of applications, from cookware to industrial machinery. Its durability, strength, and heat retention properties make it a popular choice for a variety of uses.

Cookware

Cast iron cookware is renowned for its versatility in the kitchen. It can be used on various heat sources, including stovetops, ovens, grills, and even open flames like campfires. This makes it ideal for a wide range of cooking techniques, from searing and browning meats to slow-cooking, baking, and frying. Cast iron's excellent heat distribution and retention properties ensure even cooking and help maintain the desired temperature. Its durability and longevity make it a long-lasting and chemical-free option.

Induction Cooktops

Cast iron is an excellent choice for induction cooking. Induction cooktops use magnetic fields to generate heat, and cast iron, being ferrous, is naturally magnetic and conductive. This makes cast iron skillets and pans ideal for use on induction stovetops, as they can efficiently transfer heat and provide even heating.

Industrial Applications

White cast iron, in particular, is valued for its exceptional hardness, wear resistance, and strength. These properties make it ideal for applications in industries such as mining, cement production, and machinery. White cast iron is used in components that require outstanding durability, such as crusher hammers, excavator teeth, pump impellers, and grinding balls. Its ability to withstand harsh conditions, high-impact forces, and abrasive materials makes it a reliable choice in demanding industrial settings.

Cast iron care

Cast iron pans are a great option for induction cooking as they are made of ferrous metal, which is magnetic. They are also incredibly durable and can last for generations. Here are some tips for cast iron care:

Cleaning

Cast iron pans are more resilient than you might think. You can wash them with a small amount of soap and warm water, and scrub vigorously with the rougher side of a sponge to remove stuck-on food. Avoid using steel wool or metal scrubbers, as these can damage the pan's surface. If there is stubborn residue, you can use a nylon scrubbing brush or a pan scraper, and then rinse the pan under warm water. Make sure to dry the pan promptly and thoroughly with a lint-free cloth or paper towel.

Seasoning

The "seasoning" on a cast iron pan is what makes it non-stick. This is achieved by baking multiple layers of oil into the skillet, creating a rust-resistant and non-stick surface. To season your pan, wash it with hot soapy water, dry it completely, and then rub a very light layer of cooking oil or seasoning spray onto its surface. Use a paper towel to wipe away any excess oil. Place the pan in the oven upside down on the top rack at 450-500 degrees F for one hour. Allow it to cool, and repeat the process as necessary until you achieve the desired finish.

Daily Upkeep

Always make sure your cast iron pan is bone dry before stacking or hanging it for storage. Rust is the enemy of your well-earned seasoning! Slip a single paper towel into the skillet to wick away any moisture and protect the pan's surface. Clean your pan while it is still warm, using warm (not hot) water and a gentle brush or plastic pan scraper to remove stuck-on food. Dry the pan and coat it with a thin layer of oil, ensuring that the oil doesn't pool anywhere.

Cooking Tips

Cast iron pans are great for cooking a variety of dishes, including eggs, tomatoes, and fish. When using your pan, be mindful of using gentle utensils like wood, silicone, and rubber to avoid damaging the seasoning. Avoid storing food in the pan, as this can be bad for both the pan and the food. Always clean the pan right away and avoid soaking it.

Frequently asked questions