Myths and facts about cast iron cookware. How safe is a cast iron skillet? Is cast iron cookware dangerous?

Cast iron cookware is reliable, time-tested and environmentally friendly.

Modern technologies often make our life and life more convenient and easier, but in pursuit of a simple solution to everyday problems, you should not neglect safety and forget about your health.

This is especially important in relation to objects that we are near and use on a daily basis. Among them, the first item is food and its preparation, which means the kitchen, kitchen furniture and utensils.

For example, modern non-stick cookware is made from a variety of materials using synthetic coatings that can emit harmful substances that go straight into our food.

But is the potential health risk offset by the ease of use and lack of sticking?! How to choose eco-friendly cookware?

When looking for sustainable cookware, contacting proven centuries-old manufacturing techniques. One such technology is the production of cookware from bare cast iron.

Any professional chef tells you that you need to fry only in a cast-iron pan, and for stewing and languishing cast iron cookware is one of the best options.

Cast iron owes such an attitude to itself on the part of professionals to its unsurpassed ability to accumulate and smoothly release heat.

Due to its porous structure, cast iron absorbs fats well, so protect your cast iron pan from corrosion and make its surface almost non-stick You can use simple vegetable oil. To do this, it is enough to rub a few drops of vegetable oil on the surface of the pan with a clean cloth and ignite it for 2 hours in the oven at 250-270 degrees. For serious European brands, the manufacturer undertakes such training.

Finally, another health benefit of bare cast iron utensils is that such utensils give away microscopic portions of iron to food, which is very important for the proper functioning of many systems in the human body.

True, supporters of extremes go further and believe that if your dishes are made of cast iron, this does not mean that you are protected from harmful impurities and unwanted elements. When choosing cast iron cookware, you should carefully study the market and choose a good manufacturer. Important points are the place where the ore was mined, the material used to make the mold for casting the product (traditionally it is a mixture of sand, ash and water) and the origin of the steel, which is added to the alloy with cast iron for strength and durability (ed. note: this cannot be verified by the average person).

To a greater extent, you can trust manufacturers who openly declare their careful attitude to environmental issues. As a rule, these are companies with a long history, which grew up on traditional local production, such as, for example, the Swedish company Skeppshult (ed. note: a very controversial statement).

Be careful in choosing things for your home and beware of low-quality products and fakes. Don't skimp on your health.

Cast iron cookware is back in our kitchens. About the advantages and disadvantages of heavy dishes, as well as the proper care of them.

Crockery is an important element of the kitchen. This applies not only to or glass plates, enameled containers and mugs, but also products intended for cooking. Pots and pans are made from different materials, and they all have their pros and cons. Most often, you can buy items made of stainless steel, ceramics, aluminum or glass, but cast iron utensils are still present in many families in Russia.

A few words about cast iron

Cast iron is an alloy of iron with carbon, silicon and phosphorus. Products from this material are cast at a temperature of 1400 degrees, most often they do not have seams, as they are produced in special forms, which are split after manufacturing. The cast billet is carefully cleaned and processed, and then the handles and other parts are fixed on the body.

Cast-iron utensils have been known since ancient times, approximately from the 4th-6th centuries. BC. It is impossible to indicate the specific area of ​​​​its appearance, since samples belonging to the same period were found in Europe, Africa, and Asia. In Russia, the first products appeared only in the 16th century. Previously, clay containers were used for cooking hot food, but later cast-iron objects replaced them due to their more advanced qualities.

Food cooked in a cast iron pan has good taste characteristics, and the dishes themselves are durable, durable and practical. Very often, such products were inherited and used by several generations, so even now you can find cast iron products in Russia.

Advantages and disadvantages of cast iron cookware

All items made of cast iron have a number of advantages:

• Cast iron cookware has a long service life. It is one of the most durable and practically does not deteriorate. Harm can be done to it only if the pan or pan is thrown from a great height onto the stone floor. Then it will most likely break. But dishes from other materials will not withstand such tests.
• If the surface of the products is carefully looked after, then the food in them will not burn. Before cooking, it is necessary to properly heat the dishes on the stove for several minutes. Then you don't have to worry about the food burning.
• Cast iron objects are not harmed by high or low temperatures, they do not deform and have good wear resistance.
• Dishes cooked in cast iron utensils have high taste, health benefits and do not have foreign smells and tastes.

In addition to the obvious advantages, cast iron cookware has a number of minor disadvantages:

• Items made of cast iron are quite heavy. Therefore, before you buy pans and pots, you should decide in advance on the set of dishes that you plan to cook in them. For example, it is better to buy a pan for pancakes from a different material, since cast iron will not just be constantly raised during the frying process.
• If the elementary rules for caring for such dishes are not followed, they may soon become rusty. This will happen if the surface is not wiped dry after washing. Rust is removed with a stiff brush, and then the product is calcined on fire with salt and lubricated with oil. Enameled cast iron cookware does not rust, but care must be taken to prevent chips from appearing on it.
• Some foods can damage the cast iron surface by oxidizing it, such as tomatoes or apples. Therefore, it is best to avoid cooking with these ingredients.
• Storing food in cast iron cookware is also not recommended, since the metal is able to absorb the smells of long-lying food, and the food may also darken. After cooking, it is better to transfer the leftovers of the dish to plastic or glass containers.

In addition to products made from ordinary cast iron, you can also buy items covered with enamel in the store. Enameled cast iron cookware is not prone to rust as long as it does not have surface defects in the form of chips, which, unfortunately, are not uncommon. After that, the uncoated area also becomes susceptible to corrosion. If the deformation has occurred on the inside of the pan or pan, then it is better to get rid of such a product, as it can be harmful to health. In addition, the enamel coating deprives cast iron cookware of non-stick properties.

What foods are best cooked in cast iron cookware?

Ideal for cooking in cast iron cookware are various meat products, fish, mushroom and vegetable side dishes and other dishes that require long-term simmering at a low temperature. Also, cast iron cookware is suitable for cooking soups, cereals and various sauces.

Thanks to the components included in the alloy, cooked food has excellent taste. Heating occurs evenly, due to which the dish is equally fried or boiled from all sides. The almost finished dish should be removed from the heat and let it brew a little. The low thermal conductivity of the material will not allow the pan or pan to cool too quickly, so the food served on the table will have the perfect taste, aroma and color.

Such products are suitable for any type of stoves, both for gas and for glass-ceramic or induction. They can even be used on an open fire. If you remove the handle, then the cast-iron pan can be placed in.

Choosing and caring for cast iron cookware

Before buying a cast iron product, you should look at the thickness of its walls and bottom, they should be at least 5-6 mm. Usually, lids are not included with such items, so in order to avoid problems later, it is better to select dishes of standard dimensions. The bottom of the pan and pan should be flat, tightly adjacent to the surface of the stove. Cast iron cookware, and especially its inner part, should not have bumps, potholes, roughness and other flaws.

Handles are subject to special requirements. Cast and too short should be avoided, it is necessary to pay attention to the reliability and strength of their fastening to the body. In Russia, it is customary to sell products with a protective surface coating, usually oil is used for this. Some items have an enamel layer.

Caring for cast iron cookware is not difficult, but it is necessary to follow some recommendations in order not to harm the product during operation and to keep its appearance longer. After purchasing the dishes, before the first use, they should be thoroughly washed under hot water using a soft sponge dipped in detergent. Then dry it properly or wipe it and ignite it on fire until the black color of the metal turns gray. After that, the dishes must be rinsed with cold water and again dried on fire.

In a heated pot or pan, you need to pour a thick layer of table salt and fry it for ten minutes until a characteristic shooting sound. After that, pour out the salt and rinse the dishes again in cold water. Again, put on fire, heat to a warm state and, then, generously grease with vegetable oil. After that, cast iron dishes are to be calcined in an oven preheated to 180 degrees. After three hours, the oil that has dried on the surface will create a protective film that will prevent food from burning, and, therefore, will not harm health.

It is better to wash cast iron products immediately after cooking, then the dirt will be easier to remove with plain water and a sponge. It is not worth using detergents and coarse brushes, so as not to damage the protective coating, which then will have to be restored in a rather laborious and time-consuming way.

Russian-made cast-iron cookware

In Russia, there are manufacturers of cast-iron cookware that have been operating for more than a dozen years. The range of their products is huge, and the quality is in no way inferior to European models. Numerous positive reviews are proof of this. The main items made of cast iron, which are produced at the factories of Russia, are:

• pans,
• cast iron,
• cauldrons,
• boilers,
• ducklings and goslings,
• pots, etc.

Everything you ever wanted to know about cast iron pans

The cast iron skillet is a versatile workhorse, but there are many mysterious myths surrounding it. Some people argue that getting a cast iron skillet is like having a puppy at home because it's hard to care for. Others say that it cannot be washed, but only wiped with a dry cloth ... Too many unfounded claims have gathered in the world of cast iron, it's time to dispel the myths and find out the truth.

Myth 1: Cast iron pans are difficult to care for.

Cast iron is a material that can rust, crumble and crack. You need to be gentle and careful, otherwise it will break into pieces.

Reality: Cast iron is as strong as nails! In almost every family there is an old, old cast-iron frying pan, which was inherited from the grandmother. Such a frying pan can be passed down from generation to generation and still remain in excellent condition. This material cannot be destroyed.

Storing cast iron pans is very easy: stack them one on top of the other and don't worry about scratching them. Can you do this with Teflon and not damage the surface? Obviously not.

Myth 2. Cast iron heats up very evenly.

Cast iron heats up for a long time, retains heat well, which means it heats up very evenly.

Reality: No, in fact, cast iron heats up very unevenly. Thermal conductivity is the ability of a material to transfer heat from one part to another, and for cast iron it is about 3-4 times lower than for aluminum. What does it mean? Put the pan on the fire and after a while it will heat up in those places that are located exactly above the flame, while the rest of the part will remain cooler. Aluminum heats up more evenly.

To heat a cast-iron skillet evenly, place it on the stove over low heat and let it heat for 10 minutes, during which you must turn it several times.

An important advantage of cast iron is not that it can heat up evenly, but that it has a high thermal emission. An incomprehensible word, but now everything will become clear to you. Ability of cast iron give away heat is about 9-10 times higher than that of aluminum. If you put your hand to a well-heated cast-iron pan, you will feel the heat even at a height of 10-15 cm. This means that when you fry something on cast iron, not only the part of the product that touches the surface is cooked, but also a significant part above her.

For comparison, put your hand near a heated aluminum pan - you have to almost press your palm to the surface to feel the heat. Cooking meat in such dishes will not work: it will remain raw inside.

Myth 3. A well-baked cast-iron pan is as non-stick as Teflon.

The harder you heat cast iron, the more non-stick it becomes. A perfectly seasoned cast iron pan becomes perfectly non-stick.

Reality: A cast iron skillet can be truly non-stick and will allow you to cook scrambled eggs or scrambled eggs. That's true, but let's be honest. The non-stick properties of cast iron are different from those of Teflon. You can't toss a cold egg into a cast-iron skillet, heat it slowly without oil, and then gracefully brush it onto a plate, as advertised.

By the way, in fairness, let's admit that most Teflon pans are also incapable of this trick.

So. Before you start cooking in a cast iron pan, heat it well, grease it with a thin layer of fat, and then the surface will really become non-stick - food will not stick.

Myth 4. Cast iron pans cannot be washed with detergent.

Detergents spoil the surface of the cast iron pan and food begins to stick to it, so you can only wash cast iron with warm water without adding any detergents.

Reality. In fact, the surface of a cast iron pan is covered not with a thin layer of fat, but with a thin layer of polymerized fat, and this is the key difference. In a calcined cast-iron pan (greased and well heated), the fat molecules break down and form a new substance - a durable polymer that fuses with the surface of the cast iron. The substance that gives a cast iron skillet its non-stick properties is no longer oil per se. Surface active dishwashing detergents cannot affect it or damage it in any way. You can safely wash the pan with dishwashing detergent and sponge as much as you want!

The only thing not to do is to soak the pan in the sink. Try to wash it as quickly as possible and wipe it dry immediately.

Myth 5. You can't use a metal spatula in a cast iron skillet.

The non-stick layer in cast iron pans is thin and easily damaged with a metal spatula. You can only use wood, plastic or silicone.

Reality: In fact, the non-stick layer of a cast iron skillet is very strong. This is not just a film glued to the surface, as is the case with Teflon, it is a substance chemically bonded to the metal, practically soldered into it. It is impossible to scrape off this layer with a metal spatula or fork. The fork is more likely to break than the pan to be scratched.

Probably, you sometimes noticed how black pieces break off from a cast-iron pan? This is not a frying pan that breaks into pieces, as many believe. These flakes of a mysterious black substance are nothing but charred pieces of food that have stuck to the surface and you have not bothered to wash them.

Myth 6. Sour foods cannot be cooked in cast iron cookware.

Acidic foods can react with metal, releasing the harmful substance and giving the food a metallic taste.

Reality: In a calcined cast-iron pan, food comes into contact only with a layer of polymerized fat, and not with the metal itself. So in an ideal world this shouldn't be a problem. But no one is perfect, and pans also have their drawbacks. No matter how well you roasted them, there could still be a chance that tiny spots of bare metal remained and they could actually react with the acidic ingredients.

For this reason, you should not use a cast iron skillet to cook sour foods such as tomato sauce.

How to heat a cast iron skillet

Cast iron becomes non-stick only when properly calcined. Also, new cast iron can rust easily. To solve both of these problems, coat the inside of a cast-iron skillet with a thin layer of fat and heat it well on the stovetop or in the oven. Any vegetable oil or even lard will do.

At high temperatures, fat molecules are destroyed, oxidized and polymerized, that is, they form larger molecules, mix with carbon and other substances. This dense and durable bond adheres to the surface of the cast iron and fills even the smallest cracks. The surface becomes non-stick, because it acquires hydrophobic properties - it begins to repel water from itself. When you put food in the pan, the hydrophobic surface prevents sticking.

The more you cook on it, the more new polymerized layers form on the surface, which means that over time the cast iron pan gets better and better.

So you've bought a new cast iron skillet. Most of them are sold already baked, however, this usually only protects against rust, not sticking. Wash the skillet well and wipe dry. Brush thoroughly with a thin layer of vegetable oil. Preheat the oven to 180°C - 250°C. Place the oiled pan in the preheated oven and leave for 20-30 minutes. Then carefully remove and leave to cool. Repeat the whole process 2-3 times: wash, dry, oil, warm.

If over time the food starts to stick to the surface again, wash the pan thoroughly with a stiff brush and detergent, wipe dry and re-bake with a thin layer of oil.

How to care for a cast iron skillet

What does it mean to care? No, you don’t need to give her flowers and take her to the movies, but even such a strong material as cast iron needs to be taken care of.

Wash your cast iron skillet thoroughly after each use. Scrape off any stuck-on pieces of food and wash the surface thoroughly with dishwashing detergent. Regular detergent and regular sponge. Nothing complicated.

Repeat baking from time to time. Wash the pan, and then put it on the stove at the highest heat. When the water in the pan has evaporated, pour in half a teaspoon of refined vegetable oil. Spread the oil all over the inside of the pan with a paper towel. Continue heating until the pan begins to smoke slightly, then turn off the heat and let cool.

Roast, bake and stew! The more you use your cast iron skillet, the better it gets.

Wipe dry. Water is the natural enemy of iron. After washing, wipe the cast iron pan dry, otherwise water drops will lead to the formation of rust spots. Before storing the pan in the cupboard, wipe it dry, heat it on the stove to evaporate all the remaining water and grease it with a thin layer of oil.

Did you like the recipe? Save the link so you don't lose it:

10 thoughts on “”

Good afternoon. After roasting with salt and oil, black spots appeared on the new pan. We did the process twice more. Surface of uneven coloration (more or less dark spots in some places). The food seems bitter. What's this? Marriage?

Cast iron cookware people have been using for a long time, from about the 4th-6th centuries BC. It is difficult to say in which country such dishes first appeared - both in North Africa (tajine), and in Central Asia (cauldron for pilaf), and in Europe (cast iron) they found ancient cast iron kitchen utensils, cast at about the same time. It is reasonable to assume that this utensil became widely used among those peoples who by that time had learned to smelt metal from ore.

Previously, hot food was cooked in clay dishes, gradually cast-iron products forced it out of everyday life, because. cast iron had much better qualities and characteristics than clay. In poor families, cast iron pots were highly valued not so much for the taste of the food cooked in them, but for their advantageous practicality, durability and good quality, which allowed such dishes to be inherited by several generations.

What is cooked in cast iron cookware

Any meat, vegetable, mushroom or fish dishes that need long-term heat treatment at low temperatures, all kinds of soups, sauces and cereals are best obtained in cast iron cookware. High taste qualities of dishes cooked in such dishes are obtained due to the special properties of the alloy from which cast iron is made. It consists of iron and carbon with the addition of phosphorus and silicon, which provide it with reduced thermal conductivity, due to which the heating of cast iron dishes occurs gradually and evenly over the entire surface of the walls, bottom and lid, this is its advantageous difference from similar dishes made of aluminum, steel or glass. Shortly before the end of cooking in a cast-iron dish, it should be removed from the heat and left to languish until cooked - low thermal conductivity does not allow the dishes to cool too quickly, so the dish "reaches" under the influence of low temperatures, which favorably affects the quality of the finished product.

This cookware can be used on any heating element up to an open flame, it is suitable for glass ceramics and induction, without previously removing wooden or bakelite handles, it can be safely put in the oven.

Advantages of cast iron cookware

All cast iron kitchen utensils - frying pans, ducklings, pots, cauldrons, braziers, stewpans, pots, woks - are superior in many qualities to dishes made of any other material, which makes them desirable in every kitchen:

• Cast iron cookware will last longer than any other, it is almost impossible to spoil it. The only possible option for damage is that it can crack from a blow or fall from a height onto a stone or other very durable surface, but dishes made of any materials will not withstand such tests;
• With proper care, the food in this dish does not burn, over the years it only gets better. Before starting cooking, cast iron cookware should be well heated on fire for at least 3-5 minutes to avoid burning food;
• Cast iron cookware is wear-resistant and perfectly resists deformation, keeps its shape at any temperature - from the lowest to the highest;
• The main advantage of this dish is the delicate and unique taste of the food cooked in it.

Minor cons

• It is known that cast iron is quite heavy, it is not easy to cook, for example, a pile of pancakes for a large family, constantly raising and lowering a heavy pancake pan;
• Cast iron products can rust. To avoid this, the washed dishes should be wiped dry or heated over a fire. But if this still happened, you need to carefully wipe the rusted place with a hard brush, and then repeat the procedure for preparing new cast-iron cookware for use (calcined with salt and greased with oil). Enameled cast iron cookware does not rust, but chips may form on it;
• Cast iron is afraid of an acidic environment, so you should avoid cooking, for example, dishes with tomatoes on it;
• It is not recommended to store cooked food in such dishes, because. cast iron strongly absorbs odors, after cooking, food should be transferred to a container, and the dishes should be washed immediately - it is easier to wash when it is hot.

Caring for cast iron cookware

Before the first use, the dishes must be washed with hot water and a sponge to wash off possible grease residues that manufacturers can use to treat them to prevent rust. Fry on fire until the color changes from black to gray, rinse under cold water, put on fire again, dry and cover with a thick layer of coarse table salt. Continue to fry for at least 10 minutes, until the salt begins to shoot characteristically, then pour it out, and wash the dishes thoroughly with cold water again. Heat again on fire, remove and still warm generously grease with vegetable oil, which will instantly fill the pores. Next, you need to calcine it in an oven preheated to 180 degrees upside down for about 3 hours - then the oil will dry and form a strong protective film on the entire surface.

It is recommended to wash cast iron cookware immediately after cooking, then it can be easily washed with a regular kitchen sponge and running hot water. It is very undesirable to use detergents - they wash off the protective fatty film, which will have to be restored in the laborious way described above to avoid burning food.

The owners of the patent RU 2340272:

SUBSTANCE: group of inventions relates to cast iron cookware and a method for its manufacture. Cast iron cookware is made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating of iron oxide Fe 3 O 4 is formed. SUBSTANCE: method for manufacturing cast-iron utensils includes casting gray cast iron, removing sprues and scuffs, peeling, grinding, sandblasting the casting and forming a protective coating of iron oxide Fe 3 O 4 on the casting by heating it and immersing it in oil. When casting gray cast iron, silicon is introduced into the mixture in an amount of at least 4.1% in proportion to the weight of cast iron cookware. After grinding, the graphitizing annealing of the casting is performed at least twice at a temperature of 680÷800°C for 0.5÷1.0 hour, followed by cooling in air until a gray tint is achieved. The technical result consists in ensuring the stability of the material properties, geometric parameters and shape of the dishes, as well as in increasing the adhesion strength of the oxide film to the metal. 2 n. and 1 z.p. f-ly.

SUBSTANCE: group of inventions relates to cast-iron kitchen utensils for cooking, baking and frying food products, as well as to methods for their manufacture.

The prior art cast iron cookware is made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating is formed in the form of an enamel layer /GOST 24303-80. Household utensils cast iron enamelled. General technical requirements, analogue/.

The prior art method of manufacturing cast-iron utensils, including casting gray iron into a mold to obtain a bowl-shaped casting, removing sprues, scuffing, roughing, grinding, sandblasting the casting and forming a protective coating on the casting in the form of an enamel layer / Handbook of iron casting. Under the editorship of Dr. tech. Sciences N.G. Girshovich. - 3rd ed., revised. and additional - L .: Mechanical engineering. Leningrad, department, 1978. - 758 p., p. 642-645, analogue /.

The formation of a protective coating on a casting includes the application of a primer and firing, as well as the application of enamel and firing.

Applying enamel and firing is repeated 3-5 times.

The disadvantage of such cast-iron cookware and the method of manufacturing this cast-iron cookware is the formation of defects on the enamel coating of cast-iron cookware in the form of bubbles, pricks, chips and cracks.

The first two defects are associated with gas formation during firing, the latter - with stresses that arise during the thermal processing of food in the above-mentioned cast-iron utensils, at the interface between cast-iron-enamel materials due to the difference in the expansion coefficients of cast iron and enamel.

In addition, with a significant degree of oxidation of the cast iron surface, a thick, easily detachable layer of scale is formed, as a result of which the adhesion of soil and enamel is reduced.

This reduces the strength of the enamel coating and the service life of cast iron cookware with a protective coating applied in this way.

Also known from the prior art is a cast-iron dish made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating is applied in the form of a layer of preservative lubricant, consisting of 50% paraffin and 50% medical vaseline. RST Ukrainian SSR 114-88. Black cast iron cookware. General technical conditions, clauses 1.2., 2.2.2., 2.3.1., 2.5.1., analog /.

The prior art also knows a method for manufacturing cast iron cookware, including casting gray iron into a mold to obtain a bowl-shaped casting, removing sprues, scuffing, peeling, grinding, sandblasting the casting and applying a protective coating to the casting in the form of a layer of conservation lubricant, consisting of 50% paraffin and 50% medical vaseline /PCT URSR 114-88. Black cast iron cookware. General technical conditions, clause 2.5.1., analog /.

The disadvantages of such cast-iron cookware and the method of manufacturing this cast-iron cookware are the low efficiency of the anti-corrosion resistance of the protective coating, made in the form of applied preservative lubricant, both during transportation and during operation of the cast-iron cookware.

As a result, the service life of cast iron cookware with a protective coating applied in this way is significantly reduced.

Also known from the prior art is the cast-iron cookware closest in purpose and number of common features, made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating of iron oxide Fe 3 O 4 /UA 56079 A is formed (SONKIN A.L. ), 15.04.2003, the closest analog prototype/.

The casting is made of gray cast iron containing silicon in the amount of 2.5-4.0%.

The prior art also knows the closest in purpose and number of common features to the method of manufacturing cast iron utensils, including casting gray cast iron into a mold to obtain a bowl-shaped casting, removing sprues, scuffing, peeling, grinding, sandblasting the casting and forming a protective oxide coating on the casting. iron Fe 3 O 4 by heating it and immersing it in oil /UA 56079 A (SONKIN A.L.), 15.04.2003, the closest analog prototype/.

When casting gray cast iron into a mold to obtain a bowl-shaped casting, silicon is introduced into the mixture in an amount of 2.5-4.0%.

When forming on the casting of a protective coating of iron oxide Fe 3 O 4 its heating is carried out to a temperature of 830-900°C.

The disadvantages of such cast iron cookware and the method of manufacturing this cast iron cookware is its low corrosion resistance in the preparation of food products containing organic acids, including citric, acetic and lactic acids.

This is explained by the fact that the mixture contains silicon in insufficient quantities (2.5-4.0%).

As a result, the low content of silicon in gray iron does not allow for a more stable content and reduces the activity of carbon, which leads to a high degree of oxidation of the iron and has a great influence on the composition of the oxide film (Fe 3 O 4 iron oxide) on the surface of the casting.

This does not allow achieving high adhesion strength of the oxide film to the metal and reduces the service life of cast iron cookware.

In addition, with the selected heating temperature regime of 830-900°C, the cast iron heats up excessively, becomes plastic and “floats”, distorting the original shape of the casting.

As a result, the geometric parameters and shape of the casting are violated, and the high quality of cast iron cookware obtained by this method is not achieved, which reduces its operational properties.

The technical problem to be solved by the invention is in cast iron utensils and a method for manufacturing cast iron utensils by making a casting from gray cast iron with a high silicon content to provide a more stable content of it to increase the activity of carbon and its complete transformation into graphite during heat treatment of the casting in optimal modes .

The technical result, which is achieved when solving the stated technical problem, is to ensure the stability of the material properties, geometric parameters and shape of the dishes, as well as to increase the adhesion strength of the oxide film to the metal, which increases the corrosion resistance to organic acids of the coating, service life, quality and operational properties of cast iron cookware.

The technical problem posed is solved, and the technical result is achieved by the fact that in a cast iron cookware made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating of iron oxide Fe 3 O 4 is formed, according to the invention, the casting is made of gray cast iron, containing silicon in an amount of not less than 4.1%.

An increased content of silicon (not less than 4.1%) in gray cast iron leads to a more stable content of it, due to which the activity of carbon in the process of manufacturing cast-iron utensils increases and the possibility of its complete transformation into graphite is achieved during the heat treatment of the casting in optimal heating modes.

This ensures obtaining stable properties of the material of the dishes and a dense oxide film of the coating with high protective properties.

The technical problem posed is solved, and the technical result is also achieved by the fact that in the method of manufacturing cast iron utensils, including casting gray cast iron into a mold to obtain a bowl-shaped casting, removing sprues and scuffs, peeling, grinding, sandblasting the casting and forming a protective coating on the casting from iron oxide Fe 3 O 4 by heating it and immersing it in oil, according to the invention, when casting gray iron into a mold to obtain a bowl-shaped casting, silicon is introduced into the mixture in an amount of at least 4.1%, and after grinding, at least , twice, graphitizing annealing of the casting at a temperature of 680-800°C for 0.5-1.0 hours, followed by cooling in air until a gray tint is achieved.

The introduction of silicon into the composition of the charge in an increased amount (at least 4.1%) leads to a more stable content of it in cast iron, due to which the activity of carbon in the process of manufacturing cast iron cookware increases and the possibility of its complete transformation into graphite is achieved during the heat treatment of the casting in the proposed optimal heating conditions.

And multi-stage annealing of the casting after grinding and before sandblasting at a temperature of 680-800 ° C for 0.5-1.0 hours, followed by cooling in air until a gray tint is achieved, ultimately ensures stable properties of the dish material and a dense oxide film with high protective properties during the formation of a protective coating, which improves the performance properties of cast iron cookware.

The selected temperature regime of graphitizing annealing 680-800°C of the casting was determined empirically and is optimal for obtaining the best conditions for complete graphitization of carbon, stabilizing the properties of the casting material, geometric parameters and shape of the dishes, as well as increasing the adhesion strength of the oxide film to the metal during the formation of a protective coating .

It has been experimentally established that the choice of the graphitizing annealing temperature of the casting below 680°C is not appropriate, since in this case the process of carbon graphitization slows down, as a result of which the stabilization of the properties of the casting material is not achieved and the adhesion strength of the oxide film to the metal decreases during the formation of a protective coating.

It has also been experimentally established that the choice of a graphitizing annealing temperature of the casting above 800 ° C is also not advisable, since in this case the cast iron heats up excessively, becomes plastic and “floats”, distorting the original shape of the casting, as a result of which the quality of the cast iron cookware decreases.

In addition, with the selected heating temperature regime of 680-800°C, the casting acquires a crimson tint, which allows additional visual control of the temperature regime of graphitizing annealing, which is an additional technical result.

The method of manufacturing cast iron cookware has other differences, which are used in some cases of its implementation to improve the technical result.

So, in the method of manufacturing cast iron cookware, according to the invention, when forming a protective coating of iron oxide Fe 3 O 4 on the casting, it is heated to a temperature of 680-800°C.

The selected temperature regime of heating 680-800°C of the casting was determined empirically and is optimal for obtaining the best ratio of corrosion resistance, stabilization of design geometric parameters and shape, service life and quality of cast iron cookware manufactured by this method.

At a casting heating temperature of more than 800 ° C, cast iron overheats, becomes ductile and “floats”, distorting the original shape of the casting, and the thickness of the oxide film layer increases excessively, as a result of which the corrosion resistance of the protective coating is also reduced, as well as the service life and quality of cast iron cookware .

When the selected temperature mode of heating is 680-800°C, the casting acquires a crimson tint, according to which the temperature mode of its heating is additionally visually controlled.

Thus, due to the production of a gray iron casting with a high silicon content, a more stable content of it is provided to increase the activity of carbon and its complete transformation into graphite during the heat treatment of the casting in the proposed optimal heating modes.

This makes it possible to ensure the stability of the material properties, geometric parameters and shape of the cookware, as well as to increase the adhesion strength of the oxide film to the metal, which increases the corrosion resistance to organic acids of the coating, the service life, quality and performance properties of cast iron cookware.

From the prior art, the applicant has not identified solutions that coincide with the totality of common and distinctive essential features of an improved cast iron cookware and an improved method for manufacturing cast iron cookware, on the basis of which it can be concluded that the claimed technical solutions of this group of inventions are not part of the state of the art and meet the invention criterion " novelty".

From the prior art, the applicant also did not find solutions that coincide with the distinctive essential features of the improved cast iron cookware and the improved method for manufacturing cast iron cookware.

Based on this, it can be concluded that the claimed technical solutions of this group of inventions are not obvious to a specialist, that is, they do not emerge from the prior art and meet the criterion of the invention "inventive step".

In an example of a specific implementation, the inventive cast-iron cookware is made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating of iron oxide Fe 3 O 4 is formed.

The casting is made of gray cast iron containing silicon in an amount of at least 4.1%.

The carbon in cast iron is in the form of graphite.

The metal base of cast iron is ferrite.

In an example of a specific implementation, the inventive method for manufacturing such cast iron cookware is carried out as follows.

For casting cast iron cookware, gray cast iron is used, the chemical composition of which includes iron, as well as in amounts permitted by health authorities, carbon, silicon, manganese, phosphorus and sulfur with a permissible content of chromium, nickel and copper.

First, a charge is prepared for melting gray cast iron, into which the necessary components are introduced to obtain cast iron with the required chemical composition.

Silicon is introduced into the composition of the mixture in an amount of at least 4.1%.

The amount of silicon is chosen in proportion to the mass of cast iron cookware.

For cast-iron utensils of small mass, such as pancake pans, silicon is introduced in an amount close to 4.1%.

The greater the mass of cast iron cookware, the greater the amount of silicon introduced into the charge to improve the filling of the mold with cast iron melt.

For example, for a pan, silicon is introduced in an amount close to 7.0%.

After the charge is melted, gray iron is cast into a mold to obtain a bowl-shaped casting.

In practice, gray cast iron is used for casting cast iron utensils with mainly the following chemical composition (in percent):

The presence of chromium up to 0.2%, nickel up to 0.3% and copper up to 0.5% is allowed.

Cup-shaped castings are used to make a variety of cast iron kitchen utensils, including:

frying pan round with one handle;

frying pan round with two handles;

frying pan crepe maker round with one handle;

frying pan stewpan round with one handle;

frying pan stewpan round with two handles;

frying pan with two handles;

saucepan with a lid;

other utensils.

Then the casting is subjected to mechanical processing, during which the removal of sprues, scratches, peeling and grinding of the surface are sequentially performed.

After grinding, the graphitizing annealing of the casting is performed at least twice at a temperature of 680-800°C for 0.5-1.0 hours, followed by cooling in air until a gray tint is achieved.

Such a temperature regime of graphitizing annealing of 680-800°C of the casting is optimal for obtaining the best conditions for complete graphitization of carbon, stabilizing the properties of the casting material, geometric parameters and shape of dishes, as well as increasing the adhesion strength of the oxide film to the metal when forming a protective coating of iron oxide Fe 3 O 4 .

When the temperature of the graphitizing annealing of the casting is less than 680°C, the carbon graphitization process slows down, as a result of which the stabilization of the properties of the casting material is not achieved and the adhesion strength of the oxide film to the metal decreases during the formation of a protective coating of iron oxide Fe 3 O 4 .

When the temperature of the graphitizing annealing of the casting is more than 800°C, the process is also not advisable, since in this case the cast iron heats up excessively, becomes plastic and “floats”, distorting the original shape of the casting, as a result of which the quality of the cast iron cookware decreases.

After that, the surface is sandblasted on a sandblasting machine and a protective coating of iron oxide Fe 3 O 4 is formed on the casting by heating it in a heating device and immersing it in oil.

When forming a protective coating of iron oxide Fe 3 O 4 on the casting, it is heated to a temperature of 680-800°C.

Such a temperature regime of heating 680-800°C cast iron is optimal for obtaining the best ratio of corrosion resistance, stabilization of design geometric parameters and shape, service life and quality of cast iron cookware manufactured by this method.

When the heating temperature of the casting is less than 680°C, the thickness of the oxide film layer decreases excessively, as a result of which the corrosion resistance of the protective coating decreases, as well as the service life and quality of cast iron cookware.

When the heating temperature of the casting is more than 800°C, the cast iron heats up excessively, becomes plastic and “floats”, distorting the original shape of the casting, and the thickness of the oxide film layer increases excessively, as a result of which the corrosion resistance of the protective coating decreases, as well as the service life and quality of the cast iron cookware.

With the selected temperature regime of heating 680-800°C gray cast iron, the casting acquires a crimson tint, according to which the temperature regime of its heating is additionally visually controlled.

The invention is illustrated by examples 1-5 of the implementation of the method for manufacturing cast iron cookware with different temperature conditions for heating the casting.

Cast-iron utensils were made - a crepe pan, made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating of iron oxide Fe 3 O 4 was formed.

The casting was made of gray cast iron containing silicon in the amount of 4.0%.

After grinding, the graphitizing annealing of the casting was performed once at a temperature of 670°C for 0.4 hours, followed by cooling in air until a gray tint was achieved.

When forming a protective coating of iron oxide Fe 3 O 4 on the casting, it was heated to a temperature of 670°C and immersed in oil.

At such a temperature of one-time graphitizing annealing of the casting for 0.4 hours, followed by cooling in air until a gray tint was achieved, the carbon graphitization process slowed down, as a result of which stabilization of the properties of the casting material was not achieved and the adhesion strength of the oxide film to the metal decreased during the formation of a protective coating from iron oxide Fe 3 O 4 .

However, the thickness of the oxide film layer decreased, as a result of which the corrosion resistance of the protective coating and the service life of cast iron cookware decreased.

Cast iron utensils were made - a frying pan with a small mass, made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating of iron oxide Fe 3 O 4 was formed.

The casting was made of gray cast iron containing silicon in the amount of 4.1%.

The method of manufacturing such cast-iron utensils included all the operations of the proposed method.

After grinding, the graphitizing annealing of the casting was performed twice at a temperature of 680°C for 0.5 hour, followed by cooling in air until a gray tint was achieved.

When forming a protective coating of iron oxide Fe 3 O 4 on the casting, it was heated to a temperature of 680°C and immersed in oil.

At this temperature of two-time graphitizing annealing of the casting for 0.5 hour, followed by cooling in air until a gray tint is achieved, the graphitization process of carbon is activated, as a result of which stabilization of the properties of the casting material is achieved and the adhesion strength of the oxide film to the metal increases during the formation of a protective oxide coating. iron Fe 3 O 4 .

With this mode of heating and immersion in oil, the initial geometric parameters and shape of the casting did not change and corresponded to its design values.

The strength of the protective coating, as well as the quality and performance properties of cast iron cookware obtained by this method, are satisfactory.

Cast iron utensils were made - a frying pan with an average weight, made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating of iron oxide Fe 3 O 4 was formed.

The casting was made of gray cast iron containing 5.5% silicon.

The method of manufacturing such cast-iron utensils included all the operations of the proposed method.

After grinding, the graphitizing annealing of the casting was performed twice at a temperature of 740°C for 0.75 hours, followed by cooling in air until a gray tint was achieved.

When forming a protective coating of iron oxide Fe 3 O 4 on the casting, it was heated to a temperature of 740°C and immersed in oil.

At this temperature of two-time graphitizing annealing of the casting for 0.75 hours, followed by cooling in air until a gray tint is reached, the carbon graphitization process is even more activated.

With this mode of heating and immersion in oil, the initial geometric parameters and shape of the casting did not change and corresponded to its design values.

The thickness of the oxide film layer increased, as a result of which the corrosion resistance of the protective coating and the service life of cast iron cookware increased.

The method of manufacturing such cast-iron utensils included all the operations of the proposed method.

After grinding, the graphitizing annealing of the casting was performed three times at a temperature of 800°C for 1.0 hour, followed by cooling in air until a gray tint was achieved.

At this temperature of the three-time graphitizing annealing of the casting for 1.0 hour, followed by cooling in air until a gray tint is reached, the carbon graphitization process is even more activated.

As a result, complete stabilization of the properties of the casting material was achieved and the strength of the adhesion of the oxide film to the metal increased during the formation of a protective coating of iron oxide Fe 3 O 4 .

With this mode of heating and immersion in oil, the initial geometric parameters and shape of the casting did not change and corresponded to its design values.

The thickness of the oxide film layer increased, as a result of which the corrosion resistance of the protective coating and the service life of cast iron cookware increased.

The strength of the protective coating, as well as the quality and performance properties of cast iron cookware obtained by this method, are good.

Cast iron utensils were made - a saucepan with an average weight, made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating of iron oxide Fe 3 O 4 was formed.

The casting was made of gray cast iron containing silicon in the amount of 7.0%.

The method of manufacturing such cast-iron utensils included all the operations of the proposed method.

After grinding, the graphitizing annealing of the casting was performed three times at a temperature of 810°C for 1.1 hours, followed by cooling in air until a gray tint was achieved.

Under this mode of graphitizing annealing, the cast iron heated up excessively, became ductile and “floated”, distorting the original shape of the casting, and the thickness of the oxide film layer increased excessively, as a result of which the corrosion resistance and service life of the protective coating decreased.

When forming a protective coating of iron oxide Fe 3 O 4 on the casting, it was heated to a temperature of 800°C and immersed in oil.

With this mode of heating and immersion in oil, the same processes occurred that were characteristic of the graphitizing annealing of the casting.

As a result, the initial geometric parameters and shape of the casting changed and did not correspond to its design values.

The strength of the protective coating, as well as the quality and performance properties of cast iron cookware obtained by this method, are unsatisfactory.

Examples 2, 3, 4 indicate that an increased silicon content (not less than 4.1%) in cast iron, as well as the declared modes of graphitizing annealing and casting heating, are optimal to ensure stabilization of material properties, geometric parameters and shape of dishes.

This makes it possible to increase the adhesion strength of the oxide film to metal, corrosion resistance to organic acids, service life, quality and performance properties of cast iron cookware.

Examples 1, 5 indicate that a reduced silicon content (less than 4.1%), as well as performing graphitizing annealing and heating of the casting outside the declared modes is not advisable, since this does not provide stabilization of the material properties, the geometric parameters and shape are distorted utensils.

This leads to a decrease in the adhesion strength of the oxide film to the metal, corrosion resistance to organic acids, service life, quality and performance properties of cast iron cookware.

The proposed cast iron utensils and the method for manufacturing cast iron utensils can be repeatedly implemented industrially at any enterprise for casting household cast iron utensils using standard equipment and traditional materials, which indicates that the claimed technical solutions of this group of inventions meet the invention criterion "industrial applicability".

1. Pig-iron cookware made in the form of a bowl-shaped casting made of gray cast iron, on the surface of which a protective coating of iron oxide Fe 3 O 4 is formed, characterized in that the casting is made of gray cast iron containing silicon in an amount of at least 4.1% proportional to the weight of the cast iron cookware.

2. A method for manufacturing cast iron utensils, including casting gray cast iron into a mold to obtain a bowl-shaped casting, removing gates and scuffs, peeling, grinding, sandblasting the casting and forming a protective coating of iron oxide Fe 3 O 4 on the casting by heating and immersing it in oil, characterized in that when casting gray cast iron into a mold to obtain a bowl-shaped casting, silicon is introduced into the mixture in an amount of at least 4.1% in proportion to the weight of the cast-iron utensils, and after grinding, graphitizing annealing of the casting is performed at least twice at a temperature of 680÷800°C for 0.5÷1.0 h, followed by cooling in air until a gray tint is achieved.

Cast iron cookware and method for making cast iron cookware