Environmental friendliness of cast iron cookware. Myths and facts about cast iron cookware Composition of cast iron for cookware

When buying another set of dishes, few of us think about the dangers of a new purchase. Housewives are happy to update their kitchen equipment, choosing new items based on their appearance. In other words, most women buy dishes based on the principle of like it or not. But as practice shows, today there are samples of kitchen equipment on sale that can harm human health. How to choose safe and durable cookware?

About the article:

Safety utensils

In the assortment of modern stores you can find various types kitchen containers made from various materials. You shouldn’t rush and buy the first pot or pan you like. First, you need to find out from the seller or from the information on the label from the manufacturer what material this product is made of.

• Cast iron
• Clays
• Of stainless steel
• With enamel surface

Any other material used for production kitchen utensils may cause significant harm to human health.

If the product is of poor quality, made from a material that contains nickel, the following effects are possible:

• Release of toxic substances during heating.
• Causing a severe allergic reaction that leads to poisoning.
• Entry into the gastrointestinal tract harmful substances, which can cause an unpredictable reaction in the body.

About the benefits and harm of different dishes

Cast iron kitchen utensils are great for frying and boiling any food. Cast iron has unique environmentally friendly properties. Under the influence of high temperatures this material does not emit any harmful substances, which means it is absolutely safe for humans. An interesting fact is that over time, cast iron cookware becomes even safer and much more durable.

Kitchen utensils made of aluminum are considered to be the most dangerous for human well-being. Under the influence of high temperatures, ions are released from the metal. If you boil milk or any dish with an acidic environment in an aluminum ladle, dangerous ions combine with the acids contained in the product and form a dangerous compound.

Knowing the harm from aluminum cookware prohibited:

• Cook in these pans vegetable soups and fry any food.
• Use these containers for daily cooking.
• Store any food in them.

If possible, you should stop using aluminum kitchen utensils and opt for cookware made from other, more harmless materials.

Copper utensils are not harmful to health. During heating, copper ions can enter food, but they do not pose any particular danger to the body, since they are very quickly eliminated by the excretory system. But still, cooks know about the dangers of copper utensils, which consists in destruction large quantity vitamins contained in vegetables and fruits. Considering this fact It is recommended to cook meat and fish without vegetables in copper pans.

Popular enamel kitchen utensils are safe in most cases. However, you need to know the secret.

It turns out that the following enamel colors are considered the most harmless to human health:

• Snow White
• Creamy beige
• Sky gray
• Black
• Cobalt

Yellow, red and brown enamel are not able to protect the user from ions that form in the metal when heated.

Popular sets of saucepans from of stainless steel can also be harmful to health. If you buy cheap Chinese cookware, you will probably suffer from its use. Chinese stainless steel contains a high nickel content. Under the influence of high temperatures and due to the influence of acids contained in vegetables and fruits, nickel forms harmful compounds. Chefs do not recommend preparing vegetable juices in stainless steel containers. Because when heated, acids are activated and react with nickel.

The benefits and harms of plastic dishes are clearly demonstrated when heated. On the one hand, there are convenient containers in which most housewives store ready-made dishes. On the other hand, it is better not to heat plastic dishes. When exposed to high temperatures, plastic releases chemical components harmful to humans that penetrate food. Moreover, low-quality plastic can melt when heated. Considering the negative aspects plastic dishes It is not recommended to use it daily.

About dishwashing detergents

When studying the degree of harmfulness of dishes made from a particular material, let’s not forget that there is harm from dish detergents. Washing kitchen utensils is a mandatory daily activity. Of course, every housewife uses fashionable chemicals for washing. Are they harmful to health? The question is rhetorical. Of course they are harmful. However, to reduce the harmful effects after soaping plates and pots, it is recommended to rinse the equipment as thoroughly as possible.

In custody

So, most safe species dishes are cast iron, clay, enameled. They do not emit harmful substances when exposed to high temperatures and do not enter into hazardous chemical reactions with acids contained in products. When choosing detergents and sponges for washing kitchen utensils, it is recommended to opt for products with minimum quantity hazardous components.

Cast iron cookware is making a comeback in our kitchens. About the advantages and disadvantages of heavy cookware, as well as proper care for her.

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

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 molds, which are split after production. The cast blank is carefully cleaned and processed, and then handles and other parts are attached to the body.

Cast iron cookware has 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 dating back 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 to prepare hot food, but later cast iron objects replaced them due to their more advanced qualities.

Food cooked in a cast iron frying pan has good taste, and the cookware itself is strong, durable and practical. Very often, such products were passed down by inheritance and were 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. It can only be harmed if a frying pan or pot is thrown from a great height onto a stone floor. Then it will most likely split. But dishes made from other materials will not withstand such tests.
• If you carefully care for the surface of the products, the food in them will not burn. Before cooking, it is necessary to warm up the dishes on the stove for several minutes. Then you don't have to worry about the food burning.
• Items made of cast iron are not harmed by high or low temperature, they do not deform and have good wear resistance.
• Dishes cooked in cast iron cookware have high taste qualities, beneficial and do not have any foreign odors or tastes.

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

• Items made of cast iron are quite heavy. Therefore, before buying frying 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 be easy to constantly lift during the frying process.
• If the basic rules for caring for such utensils are not followed, they may soon become covered with rust. 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 over a fire with salt and lubricated with oil. Enameled cast iron cookware does not rust, but care must be taken to ensure that it does not become chipped.
• Some foods can harm the cast iron surface by oxidizing it, such as tomatoes or apples. Therefore, it is better to avoid preparing dishes with these ingredients.
• Storing food in cast iron dishes is also not recommended, since the metal can absorb the odors of food that has been sitting for a long time, and the food may also darken. After cooking, it is better to transfer the leftover food into plastic or glass containers.

In addition to products made from ordinary cast iron, you can also buy items coated with enamel in the store. Enameled cast iron cookware is not subject to rust as long as it does not have defects on the surface in the form of chips, which, unfortunately, are not uncommon. After this, the uncoated area also becomes susceptible to corrosion. If the deformation occurred on inside frying pans or pots, 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 its 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 low temperatures. Cast iron cookware is also suitable for cooking soups, cereals and various sauces.

Thanks to the components included in the alloy, the prepared food has excellent taste. Heating occurs evenly, due to which the dish is evenly fried or boiled on all sides. Practically ready dish should be removed from the heat and allowed to brew a little. The low thermal conductivity of the material will prevent the frying pan or pan from cooling too quickly, so the food served on the table will have perfect taste, aroma and color.

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

Selection and care of cast iron cookware

Before you buy a cast iron product, you should look at the thickness of its walls and bottom; they should be at least 5-6 mm. Usually, such items do not come with lids, so to avoid problems later, it is better to select the dishes standard dimensions. The bottom of the frying pan and saucepan should be flat and fit tightly to the surface of the stove. Cast iron cookware, and especially its inner part, should not have any bumps, potholes, roughness or other defects.

Handles should be presented special requirements. It is better to avoid molded and too short ones; you need to pay attention to the reliability and strength of their attachment to the body. In Russia, it is customary to sell products with a protective surface coating; oil is usually used for this. Some items have an enamel layer.

Caring for cast iron cookware is simple, but you need to follow some recommendations so as not to harm the product during operation and preserve it longer appearance. Having purchased the dishes, before using them for the first time, they should be thoroughly washed under hot water using a soft sponge soaked in detergent. Then dry or wipe thoroughly and heat over a fire until the black color of the metal turns gray. After which the dishes must be rinsed cold water and dry again on the fire.

Pour into a heated saucepan or frying pan. thick layer table salt and fry it for ten minutes until it produces a characteristic shooting sound. After this, pour out the salt and rinse the dishes again in cold water. Put it on the fire again, heat until warm and then generously grease with vegetable oil. After this, the cast iron dishes must be calcined in an oven preheated to 180 degrees. After three hours, the oil that has dried on the surface will create protective film, which will prevent food from burning and, therefore, will not cause harm to health.

It is better to wash cast iron products immediately after cooking, then dirt will be easier to remove plain water and a sponge. You should not use detergents or rough brushes so as not to damage the protective coating, which will then have to be restored in a rather labor-intensive and time-consuming manner.

Russian-made cast iron cookware

In Russia there are manufacturers of cast iron cookware that have been operating for decades. The range of their products is huge, and the quality is in no way inferior to European standards. Numerous positive reviews are proof of this. The main cast iron items produced in Russian factories are:

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

Cast iron scares many people with its weight and vagaries; there are already many myths about it that do not always correspond to reality.

1. The best cast iron frying pan is the one left over from your grandmother. They don't make things like that these days.

It is not true. Modern cast iron's reputation has been somewhat spoiled by manufacturers who are fond of high technology“non-stick coating”, which in the case of cast iron is simply redundant. But there are also those manufacturers who make cast iron cookware “the old fashioned way” - without enamel and other frills.

2. Cast iron cookware requires preparation for use.

This is true. Firstly, before use, the dishes must be thoroughly washed, heated on the stove to a temperature above 100°C and applied thin layer vegetable oil. This contributes to a rapid increase in the thickness of the required oil film on the surface of cast iron, which is the “natural non-stick coating”.

3. Cast iron cookware can be washed with any detergent.

Not true. You should not use modern soap products, which will destroy the necessary oil film. It is better to use abrasives, cast iron is a porous material, small scratches (even if they occur) will cause less damage to it than caustic alkalis, which instantly kill everything fat and living. For the same reason, you should not wash cast iron in dishwashers.

4. Cast iron is an eternal material; nothing can spoil it.

Looks like it's true. Indeed, cast iron cookware has no shelf life, and the more often you use it, the better it serves you. However, cast iron can also be “killed”. If you store food in it, or soak it for a long time before washing, or do not wipe it dry, cast iron may not only rust (which is not a drawback and can be easily eliminated), but it may pick up some kind of fungus. Cast iron does not like moisture. He loves the heat.

5. Enameled cast iron is easier to handle.

There's probably something in it after all. In any case, the enamel coating definitely has three undeniable advantages:

– it does not absorb odors,
– allows you to preserve food without damaging it,
- does not require preliminary preparation for operation.

6. Cast iron is only suitable for slow simmering.

This is completely untrue. Cast iron is the record holder for homemade “fast food”. Yes, it takes a long time to heat up, but it can withstand very high temperatures And better than any other utensils keep warm. There is no other material that is ideal for frying steaks for a minute, when the flame walks through the pan. You just need to wait a little while for this frying pan to heat up, and then start the process. In a large cast-iron cauldron, ordinary potatoes are fried in a couple of minutes, even if they are not cut into small strips, but placed in halves.

A cast iron pot is a pot from a fairy tale that cooks itself, as if by magic. It requires minimal care, but it saves you time and effort in the cooking process itself. Cast iron is used for frying, baking, simmering, steaming and deep-frying.

Owners of patent RU 2340272:

The group of inventions relates to kitchen 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. The method of making cast iron cookware includes casting gray cast iron, removing sprues and burrs, roughing, grinding, sandblasting the casting and forming on the casting protective coating from iron oxide Fe 3 O 4 by heating it and immersing it in oil. When casting gray cast iron, silicon is introduced into the charge in an amount of at least 4.1% in proportion to the weight of the cast iron cookware. After grinding, 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 discoloration is achieved. The technical result consists in ensuring the stability of the material properties, geometric parameters and shape of the dishes, as well as increasing the adhesion strength of the oxide film to the metal. 2 n. and 1 salary f-ly.

The group of inventions relates to cast iron kitchen utensils for cooking, baking and frying food products, as well as methods for its manufacture.

From the prior art, cast iron cookware is known, 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 a layer of enamel / GOST 24303-80. Household cookware made of cast iron, enameled. Are common technical requirements, analog/.

A method of manufacturing cast iron cookware is known from the prior art, including casting gray cast iron into a mold to obtain a bowl-shaped casting, removing sprues, scoring, roughing, grinding, sandblasting the casting and forming a protective coating on the casting in the form of a layer of enamel /Handbook of Cast Iron Casting. Edited by Dr. Tech. Sciences N.G. Girshovich. - 3rd ed., revised. and additional - L.: Mechanical engineering. Leningrad, department, 1978. - 758 pp., pp. 642-645, analogue/.

Forming a protective coating on a casting involves priming and firing, as well as enamel application 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, pinholes, chips and cracks.

The first two defects are associated with gas formation during firing, the latter - with stresses arising during the temperature processing of food in the mentioned cast iron cookware, at the cast iron-enamel interface due to the difference in the expansion coefficients of cast iron and enamel.

In addition, with a significant degree of oxidation of the surface of an iron casting, a thick, easily removable layer of scale is formed, as a result of which the adhesion of the 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.

Cast iron cookware is also known from the prior art, 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 petroleum jelly. RST USSR 114-88. Black cast iron cookware. Are common technical specifications, clause 1.2., 2.2.2., 2.3.1., 2.5.1., analog/.

The prior art also knows a method for manufacturing cast iron cookware, which includes casting gray cast iron into a mold to obtain a bowl-shaped casting, removing sprues, scoring, roughing, 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 petroleum jelly / PCT URSR 114-88. Black cast iron cookware. General technical conditions, clause 2.5.1., analogue/.

The disadvantages of such cast iron cookware and the method of manufacturing this cast iron cookware are the low effectiveness of the anti-corrosion resistance of the protective coating, made in the form of an applied conservation 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.

The closest in purpose and quantity is also known from the prior art. common features 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 /UA 56079 A (SONKIN A.L.), 04/15/2003, the closest analogue prototype/.

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

Also known from the prior art is the method of manufacturing cast iron cookware that is closest in purpose and number of common features, including casting gray cast iron into a mold to obtain a bowl-shaped casting, removing sprues, scoring, stripping, 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.), 04/15/2003, the closest analogue prototype/.

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

When forming a protective coating of iron oxide Fe 3 O 4 on the casting, it is heated 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 when preparing food products containing organic acids, including citric, acetic and lactic acids.

This is explained by the fact that the charge contains silicon in insufficient quantities (2,5-4,0%).

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

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

In addition, at the selected heating temperature 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 high quality The quality of cast iron cookware obtained by this method is not achieved, which reduces its performance properties.

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

The technical result that is achieved when solving the technical problem is to ensure the stability of the properties of the material, 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 performance properties of cast iron cookware.

The stated technical problem is solved, and the technical result is achieved by the fact that in 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 at least 4.1%.

The increased silicon content (at least 4.1%) in gray cast iron leads to a more stable content, thereby increasing the activity of carbon in the manufacturing process of cast iron cookware and achieving the possibility of its complete transformation into graphite during heat treatment of the casting in optimal heating conditions.

This ensures stable properties of the cookware material and a dense coating with high protective properties.

The stated technical problem is solved, and the technical result is also achieved by the fact that in the method of manufacturing cast iron cookware, including casting gray cast iron into a mold to obtain a bowl-shaped casting, removing sprues and burrs, stripping, 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 cast iron into a mold to obtain a bowl-shaped casting, silicon is introduced into the charge 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 tarnish color 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 in cast iron, due to which the activity of carbon increases in the process of manufacturing cast iron cookware and the possibility of its complete transformation into graphite is achieved during heat treatment of the casting in the proposed optimal heating modes.

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 tarnish color is achieved ultimately ensures stable properties of the tableware material and a dense oxide film with high protective properties when forming a protective coating, which improves the performance properties of cast iron cookware.

The selected temperature regime for graphitizing annealing 680-800°C of the casting was determined experimentally and is optimal for obtaining the best conditions for complete graphitization of carbon, stabilization of the properties of the casting material, geometric parameters and shape of the cookware, 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 choosing a graphitizing annealing temperature of a casting less than 680°C is not advisable, since in this case the process of carbon graphitization slows down, as a result of which stabilization of the properties of the casting material is not achieved and the adhesion strength of the oxide film to the metal during the formation of a protective coating is reduced.

It has also been experimentally established that choosing a graphitizing annealing temperature of a casting greater than 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, resulting in a decrease in the quality of cast iron cookware.

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

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

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

When the heating temperature of the casting exceeds 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, as well as the service life and quality of cast iron cookware, also decrease .

At the selected heating temperature regime of 680-800°C, the casting acquires a crimson tarnish color, by which the temperature regime of its heating is additionally visually monitored.

Thus, by manufacturing a casting from gray cast iron with a high silicon content, its more stable content is ensured to increase the activity of carbon and its complete transformation into graphite during 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, 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 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 This group of inventions is not part of the prior art and meets the invention criterion of “novelty”.

The applicant also did not identify solutions from the prior art that coincide with the distinctive essential features improved cast iron cookware and an improved method of making cast iron cookware.

Based on this, we can conclude that the claimed technical solutions of this group of inventions are not obvious to a specialist, that is, they do not fall outside the state of the art and meet the invention criterion of “inventive step”.

In a specific example, 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%.

Carbon in cast iron is in the form of graphite.

The metal base of cast iron is ferrite.

In a specific example, the claimed 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 quantities permitted by health authorities, carbon, silicon, manganese, phosphorus and sulfur with the permitted content of chromium, nickel and copper.

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

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

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

For light weight cast iron cookware, such as a pancake pan, silicon is added 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 casting mold with molten cast iron.

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

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

In practice, gray cast iron with predominantly the following chemical composition (in percentage) is used for casting cast iron cookware:

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

Bowl-shaped castings are used to make various cast iron kitchen utensils, including:

round frying pan with one handle;

round frying pan with two handles;

round pancake pan with one handle;

round frying pan with one handle;

round frying pan with two handles;

frying pan with two handles;

saucepan with lid;

other dishes.

The casting is then subjected to machining, which involves sequentially removing sprues, scoring, roughing and grinding the surface.

After grinding, 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 discoloration is achieved.

This 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 the cookware, as well as increasing the adhesion strength of the oxide film to the metal during the formation of a protective coating of iron oxide Fe 3 O 4 .

When the temperature of graphitizing annealing of the casting is less than 680°C, the process of carbon graphitization slows down, as a result of which 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 graphitizing annealing of a 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, resulting in a decrease in the quality of cast iron cookware.

After this, the surface is sandblasted using a sandblasting unit 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.

This temperature regime of heating 680-800°C of 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, resulting in a decrease in the corrosion resistance of the protective coating, as well as the service life and quality of cast iron cookware.

When the heating temperature of the casting exceeds 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, resulting in a decrease in the corrosion resistance of the protective coating, as well as the service life and quality of cast iron cookware.

At the selected heating temperature of 680-800°C of gray cast iron, the casting acquires a crimson tarnish color, by which the temperature of its heating is additionally visually monitored.

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

Cast iron cookware was made - a pancake frying 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 an amount of 4.0%.

After grinding, 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 tarnish color 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 this temperature of a one-time graphitizing annealing of the casting for 0.4 hours, followed by cooling in air until a gray tarnish color is achieved, the process of carbon graphitization 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 was reduced when forming a protective coating from iron oxide Fe 3 O 4.

However, the thickness of the oxide film layer decreased, resulting in a decrease in the corrosion resistance of the protective coating and the service life of cast iron cookware.

Cast iron cookware was made - a pancake 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 an amount of 4.1%.

The method for manufacturing such cast iron cookware included all the operations of the proposed method.

After grinding, graphitizing annealing of the casting was performed twice at a temperature of 680°C for 0.5 hours, followed by cooling in air until a gray tarnish color 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 hours, followed by cooling in air until a gray tarnish color is achieved, the process of carbon graphitization was activated, as a result of which stabilization of the properties of the casting material was achieved and the adhesion strength of the oxide film to the metal increased 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 cookware was made - a frying pan with medium 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 an amount of 5.5%.

The method for manufacturing such cast iron cookware included all the operations of the proposed method.

After grinding, 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 tarnish color 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 tarnish color is achieved, the process of carbon graphitization was further intensified.

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, resulting in an increase in the corrosion resistance of the protective coating and the service life of cast iron cookware.

The method for manufacturing such cast iron cookware included all the operations of the proposed method.

After grinding, 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 tarnish color was achieved.

At this temperature, three times graphitizing annealing of the casting for 1.0 hour followed by cooling in air until a gray tarnish color was achieved, the process of carbon graphitization was further intensified.

As a result, complete stabilization of the properties of the casting material was achieved and the adhesion strength of the oxide film to the metal was 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, resulting in an increase in the corrosion resistance of the protective coating and the service life of cast iron cookware.

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 cookware was made - a saucepan with medium 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 an amount of 7.0%.

The method for manufacturing such cast iron cookware included all the operations of the proposed method.

After grinding, 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 tarnish color was achieved.

Under this regime of graphitizing annealing, the cast iron became excessively heated, became plastic and “floated”, distorting the original shape of the casting, and the thickness of the oxide film layer increased excessively, resulting in a decrease in corrosion resistance and service life of the protective coating.

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 the increased silicon content (at least 4.1%) in cast iron, as well as the stated modes of graphitizing annealing and heating of the casting, are optimal for ensuring stabilization of the properties of the material, geometric parameters and shape of the cookware.

This allows you to increase 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.

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 stated modes is not advisable, since this does not ensure stabilization of the properties of the material, the geometric parameters and shape are distorted dishes.

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 operational properties cast iron cookware.

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

1. 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, characterized in that the casting is made of gray cast iron containing silicon in an amount of at least 4.1% proportional to the mass of cast iron cookware.

2. A method for manufacturing cast iron cookware, including casting gray cast iron into a mold to obtain a bowl-shaped casting, removing sprues and burrs, roughing, 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, characterized in that when casting gray cast iron into a mold to obtain a bowl-shaped casting, silicon is introduced into the charge 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 hours, followed by cooling in air until a gray tarnish color is achieved.

Cast iron cookware and method of making cast iron cookware

Long gone are the days when food for consumption was cooked over a fire or even eaten raw.

Nowadays, in the kitchen of every housewife there is a variety of utensils and various accessories that help in cooking.

This cookware is made in every way the latest technologies with a variety of non-stick coatings, double bottoms, air fryers and other latest devices. All this allows you to prepare very tasty and healthy food.

Pros, benefits and benefits of cast iron cookware

We all remember our grandmother’s old heavy frying pans or cauldrons. In them, the food always turned out more tasty and in the oven, over an open fire, these dishes never melted or lost the desired shape (did not become deformed).

It is made from pretty strong material - cast iron. In past times, cast iron cookware was an indispensable assistant every housewife. This cookware has many positive characteristics:

• Do you know why in the past husbands cheated on their wives less - and you try to hit them on the head with a cast-iron frying pan, and then concussion guaranteed.
• Frying pans, cauldrons, cauldrons/duckling bowls, pots - this is not the entire list of cast iron cookware. The main positive The quality of cast iron cookware is its strength.
• Its service life is practically unlimited, since this utensil is passed on from generation to generation. In addition, it can withstand high temperatures, which makes it possible to use it in ovens, stoves and open fires.
• Such dishes are enough for a long time keeps warm, this is important for dishes that require a long cooking time. True, it heats up slowly, but equally over the entire area and does not require frequent stirring. Food in pans made of cast iron is essentially non-stick., which will protect forgetful housewives from spoiled dishes.
• Another strong argument in favor of cast iron cookware is that even accessories made of metal are suitable for it.
• In addition, cast iron does not enter into chemical reactions. Cookware made of cast iron, if stored properly, does not rust over time. To do this, you need to protect it from moisture and dampness.
• Dishes made of cast iron hold their shape quite well and do not deform or scratch. Those who are concerned about their own health need to know that such utensils are absolutely safe.

Pros and cons of cast iron cookware

But besides positive qualities, cast iron cookware also has a number of disadvantages:

• Firstly, it is quite heavy. Although, some housewives can turn this disadvantage into a positive side for themselves - you can save on the gym by pumping up your arm muscles by frequently lifting the frying pan. For example, you can bake pancakes for the whole family.
• The second disadvantage is that if cast iron cookware is washed frequently and not completely dried, it will begin to rust. But this can also be avoided; the main thing is not to forget to always dry the dishes with a soft towel after washing.

Types of cast iron cookware and care for them

The first is uncoated, and the second is coated or enameled.

The main advantage of the first type is that after acquiring it, we ourselves can create it non-stick coating. The coating of such dishes is not very smooth, but this is easy to fix.

It is necessary to heat it to the highest temperature before the first use. vegetable oil or fat. This will fill the cells of the porous structure of the material. After just a few procedures of use, this frying pan will acquire required characteristics for preparing delicious food.

Cast iron cookware with enamel looks good in appearance. It is coated with matte enamel or a glossy analogue of the corresponding color. Inner surface processed with glass enamel which prevents food from burning.

This substance does not undergo any reactions with chemical elements, also withstands fairly high temperatures, does not absorb any odors (unlike uncoated cast iron with enamel, where food cannot be stored for a long time) and practically does not rust.

Cast iron cookware with enamel does not require any measures for the purpose of preliminary preparation for use. However, such dishes also have their drawbacks. It should not be exposed to temperature changes. This will cause the glass enamel to crack.

Apply hardware It is also undesirable to mix food, because this will lead to the same consequences. Cookware with cracks is contraindicated for cooking. Firstly, it will begin to rust, and secondly, it will chip further and fragments will begin to get into the food.

When choosing cast iron cookware, be sure to choose ones with walls of considerable thickness (at least 5 mm). If it is heavy, it means it is made of sufficient quantity real cast iron. It is worth remembering that the heavier the product, the better it is. The lid can be made of the same cast iron or glass, which has heat-resistant properties.

It is worth clearly deciding where the cast iron cookware will be used. If you plan to use it for both cooking and baking something, then important aspect the material of her handle remains. If it is made of wood or heat-resistant plastic, then this option is not suitable for the oven.

In this case, you need to take it with a removable handle, but you shouldn’t worry about its durability, since the fastening may not hold up over time. It is better to take one with a solid handle, it is both durable and easy to use, but there is a drawback here - it, just like the dishes themselves, heats up. Therefore, you will need to buy a potholder or mitten so as not to burn your hand.

Dishes are not picky in practice if they are made of cast iron. You just need to take proper care of it. Washing and cleaning should be done in warm water- without using any detergents. And if you resort to using them, then you need to take only liquid ones.

Do not use cleaning scrapers or various brushes on it - this will damage the surface. If suddenly something is burnt, you don’t need to scrape it off right away, you just need to pour hot water on it for a short time, then all the burnt areas will be easily cleaned.

And most importantly, do not forget that after washing it is necessary to wipe it dry, which will avoid the appearance of rust.

Every good housewife should have a cast iron cauldron in her arsenal. If you don’t have money for a new one, then go to the village to visit your grandmother. There you will undoubtedly find something of interest. Wash it thoroughly, clean it and go ahead - surprise your loved ones with culinary masterpieces!

Also, having a cast-iron frying pan in your stash, you can safely scare your husband for being late from work or having long gatherings with friends.