Cast iron is an iron-carbon alloy with a carbon content of >2.14% and impurities in tenths of a percent. In addition, cast iron contains impurities in tenths: silicon, manganese, sulfur, phosphorus, etc. In order to improve properties, alloying elements such as chromium, nickel, copper, etc. can be introduced into cast iron.

Types of cast iron

Gray cast iron Gray cast iron is an alloy of iron, silicon (from 1.2-3.5%) and carbon, also containing permanent impurities Mn, P, S. In the structure of such cast iron, most or all of the carbon is in the form of plate-shaped graphite. The fracture of such cast iron is gray in color due to the presence of graphite. Gray cast iron is used for the manufacture of lightly loaded parts operating in light conditions. For example, housings of gearboxes, pumps, electric motors, various covers, heating batteries, etc.

White cast iron White cast iron is cast iron in which carbon is chemically combined with iron. Carbon in white cast iron is in the form of cementite Fe3C - a bound state. Cementite gives shine to cast iron fractures, and graphite gives it a gray color. Therefore, cast iron, in which all carbon is in a bound state, is called white cast iron. Relatively soft and machineable. Softness comes from free carbon.

Malleable cast iron Malleable cast iron is produced by long-term annealing of white cast iron, which results in the formation of flake-shaped graphite. The metal base of such cast iron is ferrite and, less commonly, pearlite. Malleable cast iron got its name due to its increased ductility and viscosity (although it is not subject to pressure treatment). Malleable cast iron has increased tensile strength and high impact resistance. Parts of complex shapes are made from malleable cast iron: car rear axle housings, brake pads, tees, angles, etc.

High-strength cast iron has spheroidal graphite in its structure, which is formed during the crystallization process. Nodular graphite weakens the metal base as much as lamellar graphite, and is not a stress concentrator. In half cast iron, part of the carbon (more than 0.8%) is contained in the form of cementite. The structural components of such cast iron are pearlite, ledeburite and flake graphite. Ductile iron, Half cast iron

Cast iron is widely used in the production of products for various purposes. The main qualities of cast iron are low cost, good casting qualities, strength and hardness. Cast iron is used where it is necessary to obtain parts of complex shapes and sufficient strength. For example, machine beds, body parts or artistic cast-iron fences. Everyone is well aware of the artistic decorations of the embankments of St. Petersburg, made of cast iron. The openwork cast gates of the Winter Palace, as well as other monuments, are no less beautifully decorated. Scope of cast iron

In the automotive industry, engine cylinder blocks are made from cast iron. internal combustion(on modern production use cast iron with vermicular graphite), as well as crankshafts of diesel engines. Cast iron is widely used in plumbing equipment - bathtubs, sinks and kitchen sinks are made from cast iron, as well as heating radiators, pipes and fittings. For example, bathtubs made of cast iron are highly valued by experts for their reliability, durability and ease of use. Such bathrooms can serve for decades, maintaining their original appearance without changes.

Classification of cast iron according to the state diagram: cast iron with a C content from 2.14 to 4.3% - hypoeutectic cast iron with a C content from 2.14 to 4.3% - hypoeutectic cast iron with a C content of 4.3% - eutectic cast iron with a C content of 4.3% - eutectic cast iron with a C content of from 4.3 to 6.67% - hypereutectic cast irons with a C content from 4.3 to 6.67% - hypereutectic

Marking of white cast iron White cast irons are marked according to the method of their subsequent remelting into steel. M0 B1 T1 M-Marten M1 B2 T2 B-Bessemer M2 B3 T3 T-Tomaov M3 0,1,2,3-series number Purpose: for further remelting into steel and obtaining malleable cast iron Purpose: for further remelting into steel and producing malleable cast iron

Gray cast iron (foundry) Gray cast iron contains carbon in a free state in the form of graphite plates. They have good casting properties (high fluidity, low shrinkage - 1%), are well processed by cutting, but have very low ductility up to 1%. Gray cast irons are marked according to their strength.

Marking of gray cast iron unmodified (contain large graphite plates, which reduce strength) SCh10 SCh15 SCh20 SCh25 unmodified (contain large graphite plates, which reduce strength) SCh10 SCh15 SCh20 SCh25 Purpose: weights, dumbbells, frying pans, batteries, bathtubs Purpose: weights, dumbbells, frying pans, batteries, modified bathtubs (contains crushed graphite plates) SCh30 SCh50 SCh35 SCh55 SCh40 SCh60 SCh45 modified (contains crushed graphite plates) SCh30 SCh50 SCh35 SCh55 SCh40 SCh60 SCh45 Purpose: various machine parts operating under stationary conditions Purpose: various machine parts operating under stationary conditions

Annealing of malleable cast iron In an oxidizing environment, scrap iron ore scale T= T type. = min V cooling - together with the furnace Result: black-core pearlitic cast iron is obtained; higher strength values ​​are obtained. KH KH 60-3 In an oxidizing environment, scrap iron ore scale T = T type. = min V cooling - together with the furnace Result: black-core pearlitic cast iron is obtained; higher strength values ​​are obtained. KCH KCH 60-3 In a neutral environment 1) T view. = 50-60 h Black increases. max) T view = 50-60 hours Negro decreases. 750 Result: white-core ferritic cast iron CN In a neutral environment 1) T view. = 50-60 h Negro increases. max) T view = 50-60 hours Negro decreases. 750 Result: white-core ferritic cast iron KCH 37-12

High-strength cast iron High-strength cast iron contains carbon in a free state in the form of graphite balls (globules), which are obtained by modification with magnesium. Marking: HF b-8 HF 60-2 HF HF 60-2 HF Purpose: machine parts (crankshaft, gears, couplings, wheel hubs) High-strength cast irons are substitutes for steel.

Malleable cast iron Contains carbon in a free state in the form of graphite flakes. Marked: CN G kg/mm-6% Purpose: various machine parts manufactured in large batches Production of malleable cast iron 1) Casting from white cast iron with a wall thickness of up to 30 mm 2) Heat treatment (annealing)

MINISTRY OF EDUCATION, SCIENCE AND YOUTH POLICY

ZABAIKALSKY REGION

STATE EDUCATIONAL INSTITUTION

PRIMARY PROFESSIONAL EDUCATION

"VOCATIONAL SCHOOL No. 1"

Lesson on the subject "Fundamentals of Materials Science".

Developed by: teacher Fedorova N.V.

Chita, 2011

Topic: "Cast irons. Classification of cast irons"

Lesson objectives:

Educational – study the essence and concept of cast iron, classification and marking of cast iron, depict main ideas in the form of supporting diagrams; systematize the content of the material; generalize and draw conclusions.

Developmental – develop a desire for knowledge, a creative attitude towards the material being studied; core competencies: educational and cognitive, informational, social and labor, communicative; logical thinking; interest in the subject, professional activity.

Educating - to cultivate confidence in one’s abilities, respect for work and for working people, discipline, attentiveness, composure, accuracy, and a friendly atmosphere in the classroom.

Lesson type : formation of new knowledge

Lesson methods: explanatory - illustrative, partially - exploratory, heuristic conversation

Intersubject communication: chemistry, basics of plumbing and assembly work, physics.

Intrasubject connection: “Classification of materials. Mechanical properties of metals and alloys", "Technological properties of metals and alloys"

Material and technical equipment: projector, laptop, textbook “Materials Science”, educational element module “Cast irons and their properties” (01 – 31), task cards

Literature:

1. Yu.T. Chumachenko, Materials Science (Metalworking): textbook. A manual for NGOs – M.: Publishing center “Prosveshcheniye”, 2009. – 288 p.
2. A.M. Adaskin, Materials Science (Metalworking): textbook. Manual for NGOs – M.: Publishing Center “Academy”, 2008. – 204 p.

During the classes

The lesson is accompanied by a presentation

1. Organizing time(2–3 min)

1. Checking those present (submitting a report)
2. Checking the appearance
3. Checking readiness for the lesson.

2 Updating of basic knowledge of skills and motivational states.

Teacher : Hello guys! Today we will learn what cast iron is; Let's get acquainted with the types of cast iron and give brief description every type. Their application in mechanical engineering. Write down the topic of the lesson in your notebooks (using a multimedia projector, the topic of the lesson is displayed and read out on the screen).

) Updating knowledge

Teacher : Traditional blitz survey : (quick survey-game for 2-3 minutes. On the sheets of paper, students fill out answers in the form “+” if they agree with the teacher’s statement and “-” if they do not agree with the teacher’s statement). (slide 2)

1. Fluidity - the ability of metals and alloys in a molten state to fill the cavities of a casting mold (+)
2. Crystallization is the transition of a metal from a solid state to a liquid state (-)
3. Creep is the ability of a material to slowly and continuously deform plastically….(+)
4. Malleability is the ability of metals and alloys to undergo various methods machining and cutting tools.(-)
5. Shrinkage is the ability of metals and alloys to shrink in size after solidification.(+)

(Peer checking and assessment sheets are handed over to the teacher)

Motivation:

Story.

Teacher : The first information about cast iron dates back to the 6th century BC. In China, from high-phosphorus iron ores, cast iron containing up to 7% P (phosphorus), with a low melting point, was obtained, from which it was cast various products. Cast iron was also known to ancient metallurgists of the 4th-5th centuries BC. Iron production in Western Europe began in the 14th century with the advent of the first blast furnaces for smelting pig iron from ores. The resulting cast iron was used either for conversion into steel in a forge, or for the manufacture of various construction parts and weapons (cannons, cannonballs, columns, etc.).

In Russia, cast iron production began in the 16th century; Subsequently, it continuously expanded, and under Peter I, Russia surpassed all countries in the production of cast iron, but a century later it again lagged behind Western European countries. The appearance of cupola furnaces in the second half of the 18th century allowed foundries to separate from blast furnaces, i.e. marked the beginning of the independent existence of iron foundries. At the beginning of the 19th century, the production of malleable cast iron began. In the second quarter of the 20th century, alloying of cast iron began to be used, which made it possible to significantly increase its properties and obtain special cast iron (wear-resistant, corrosion-resistant, heat-resistant, etc.).

In your specialty you can also find the use of cast iron: Cast iron brake pads for carriages and tenders railways, cast iron gearboxes,industrial motors in a cast iron body, cast iron flanged valves, etc. (slides

3. Formation of new knowledge.

Teacher : Today we will discuss the topic “Cast Irons.” Classification of cast iron." (slide 1)

The ultimate goal of studying today's material is to learn to decipher the grades of cast iron. If I now give you a simple mark SCH 15 - 20 and ask you to decipher it, you don’t even know what you need to talk about. But if you are asked to describe a passerby walking down the street, without seeing him, you know what you should say. (Students list: gender, height, clothing, hair color, gait, etc.).

The classification of cast iron is precisely the algorithm by which the grade of any cast iron is deciphered.

Cast iron is an alloy of iron and carbon, with a carbon content of more than 2.14%. (slide 3)

Pig iron is produced from iron ores in blast furnaces. In addition to the base iron and carbon, cast iron contains small amounts of impurities, as well as specially introduced alloying elements. (slide 4)

Classification and properties of cast iron.

Cast iron produced in blast furnaces is divided into conversion cast iron used for conversion into steel, andcast iron , serving as one of the main components of the charge in iron foundries. Until the 70s. In the 20th century, so-called mirror cast iron (10-25% Mn) was sometimes smelted in blast furnaces, which was used as a deoxidizer in steel smelting and to produce special types of cast iron. When iron ores containing Cr, Ni, Ti and other alloying elements are used to smelt cast iron, naturally alloyed cast iron is obtained.

In the production of castings in iron foundries, cast iron is divided into: (slide 6)

1. depending on the degree of graphitization, which determines the type of fracture, - on grey , white and half(or bleached);
2. depending on the shape of graphite inclusions - into cast iron with lamellar, spherical (ductile iron), vermicular and flocculent ( malleable cast iron) graphite;
3. depending on the purpose - onstructural And cast iron with special properties;
4. By chemical composition- on doped and undoped.

(The teacher explains the characteristics of steel classification. Students, using the educational element module, build in their notebooks reference diagram)

Let's look at the following types of cast iron in more detail: (slide No. 7)

1.White cast iron obtained by primary crystallization from a liquid alloy with rapid cooling. It is an alloy in which excess carbon, not found in the iron solid solution, is present in a bound statein the form of iron carbides Fe3C(cementite), which gives cast iron a matte white color. White cast iron has high hardness, brittleness and is difficult to process, so it is not used for the manufacture of parts and is used as a pig iron, i.e. goes into the production of steel and other types of cast iron.Half cast ironcontains part of the carbon in a free state in the form of graphite, and part of it in a bound state in the form of carbides. It is used as a friction material operating under dry friction conditions (brake pads), as well as for the manufacture of parts with increased wear resistance (rolling, paper-making, flour-grinding rolls).

2. Gray (foundry) cast iron(slide No. 7) - the most widely used type of cast iron (mechanical engineering, plumbing, building structures) - has graphite inclusions lamellar forms. Obtained by primary crystallization with slow cooling. Compared to the metal base, graphite has low strength. Therefore, graphite inclusions can be considered faults that weaken the metal base. Since lamellar inclusions most strongly weaken the metal base, gray cast iron has the lowest characteristics, both in strength and ductility. The properties of graphite to form lubricating films cause a decrease in the coefficient of friction, which means wear resistance and good anti-friction properties. Gray cast irons are easy to cut and have the ability to dissipate vibrations during vibrations and variable loads. These cast irons are characterized by good fluidity and low shrinkage. Gray cast iron is used as a structural material in construction and mechanical engineering for the manufacture of low-responsibility and medium-load parts.

Marking of gray cast iron:

Letters СЧ – (indicate gray cast iron)

Numbers – tensile strength, kgf/mm 2 ;

Example SCh – 18 – Gray cast iron, 18 - – tensile strength, 18 kgf/mm 2 ;

3. Malleable iron (slide No. 8) are obtained from white by heat treatment - annealing. Which consists of long-term exposure at a temperature of 950 ° C and slow cooling. As a result, the graphite inclusions will take on a flocculent shape. These inclusions are more compact, they cut less into the metal base, and such cast iron turns out to be more durable. He can already work in tension.

Malleable cast iron is used for the manufacture of small and medium-sized thin-walled castings for critical purposes, operating under dynamic alternating loads (parts of drive mechanisms, gearboxes, brake pads, gears, hubs, etc.). However, malleable cast iron is an unpromising material due to the complex production technology and the length of the production cycle for making parts from it.

Marking of malleable cast iron:

Letters KCH – (indicate malleable cast iron)

Numbers – (1 - number - tensile strength, kgf/mm 2

Example CN – 35 – 10 - Malleable cast iron, 35 - tensile strength, 35 kgf/mm 2 , 10 - relative elongation, 10%)

4. High strength cast iron, (slide No. 9) characterized by a spherical or similar shape of graphite inclusions, is obtained by modifying liquid cast iron with additives Mg, Ce, Y, Ca and some other elements. Nodular graphite weakens the metal base to the least extent, which leads to a sharp increase in the mechanical properties of cast iron, bringing their properties closer to the properties of carbon steels, while maintaining good casting properties, machinability, and the ability to dampen vibrations. This cast iron competes with carbon steels and is also cheaper than ductile iron and steel. It is used for the manufacture of critical parts in the automotive industry (engine crankshafts, compressors, gears, cylinders, etc.). This cast iron is used to replace cast and forged steel parts, as well as parts made of ductile or regular gray cast iron.

Marking of high-strength cast irons:

Letters HF - (indicate high-strength cast iron)

Numbers –(1 - number tensile strength, kgf/mm 2 , 2 – relative elongation, %)

Example HF – 42 – 12 - Malleable cast iron, 42 - tensile strength, 35 kgf/mm 2 , 12 - relative elongation, 10%)

5. Anti-friction cast iron(slide 10) – are obtained on the basis of gray, high-strength and malleable cast irons.

Anti-friction cast irons are divided into:

1. based on gray cast iron (AChS -1, AChS -2, AChS -3, AChS -4, AChS -5, AChS - 6).
2. based on high-strength cast irons (AChV – 1, AChV – 2)
3. Based on malleable cast iron (AChK – 1, AChK – 2)

Marking of anti-friction cast iron:

Letters АЧ– (indicate anti-friction cast iron)

Numbers – brand number according to GOST

Example AChS – 2, anti-friction gray cast iron, 2 – brand number according to GOST.

6. Alloy cast irons –cast irons into which special elements are introduced to improve the properties of cast irons. (slide 11)

It is used for the manufacture of parts for steam engines and turbines, diesel engines, internal combustion engines, etc.

Marking of alloy cast irons:

Designation of alloying elements: (slide 11)

X – CHROME;

D – COPPER

T – TITANIUM

M – MOLYBDENUM

N – NICKEL

Y – ALUMINUM

C – SILICON

G – MANGANESE

F - VANADIUM

Example: ChN 1KhMD - alloy cast iron, nickel content - 1%, molybdenum and copper content - up to 1.5% (slide 12)

4. Checking the degree of mastery of the material (consolidation)(slide number 13).

Teacher: So, our lesson comes to an end. Today we introduced you to the compositions and types of cast irons and their applications in mechanical engineering. To check how well you have mastered the material, you are asked to do it yourself. test tasks in your test books. Attention to the screen.

I suggest answering the following questions:

Answer form: a combination of the number of the question and the letter of the answer.

Possible answers:

a) gray b) white c) malleable d) high-strength

Questions:

1. What is the name of cast iron in which carbon is contained in the form of cementite?
2. What is the name of cast iron produced by slow cooling?
3. What is spherical cast iron called?
4. What kind of cast iron is converted into steel?
5. What is the name of cast iron obtained by annealing?
6. What is the name of cast iron in which carbon is in the form of graphite plates?
7. What is the name of the cast iron obtained as a result of modification?
8. What is the name of cast iron with graphite in the form of flakes?
9. Which cast iron has high casting properties?
10. Which cast iron has high ductility?

Answers: (slide 14)

Teacher : Please hand in your work.

Crossword "Association"

(A crossword puzzle is shown on the board via a computer, and students fill in the correct answers in their notebooks.) (slide 15,16,17)

1. Cast iron

Main component of cast iron (IRON)

3. Non-metal

Alloys of iron with silicon, manganese (FERROALLOYS)

5. Alloying element

Component rock(SILICON)

7. Non-metal

Outstanding Personality (TITAN)

9. Alloying element

Forest (BOR)

5. Summing up the lesson

The teacher sums up the results, gives grades, notes outstanding students, focuses on their readiness to learn the material of the next lesson, and thanks them for their active and fruitful work.

6. Homework. (slide 18)

Message: “Cast irons used in mechanical engineering”

Learn the classification of cast irons and their markings (SC – 15, CC 19 – 40, ChM3N3Yu4, AChS – 5, VCh 10 – 30)

Cast iron pads brakes for railroad cars and tenders

Cast iron brake pads for railroad cars and tenders

Cast iron the alarm body / valve 16 is located, which is pressed

Catalog for cast iron gearboxes

Flanged valves cast iron with

Flanged valves cast iron with

1. Industrial motors in cast iron body.

Metal (cast iron) housings (shells) manufactured in accordance with GOST.

Classification of cast irons according to the structure of the metal base and the shape...

Cast iron is an alloy of iron and carbon, with a carbon content of more than 2.14%.

IMPURITIES HEALTHY HARMFUL MANGANESIS - increases the hardness of cast iron SILICON - increases strength and toughness, improves casting properties. SULFUR - reduces strength, worsens casting properties PHOSPHORUS - increases fragility

depending on the degree of graphitization, which determines the type of fracture, into gray, white and half (or bleached); depending on the shape of graphite inclusions - into cast iron with lamellar, spherical (high-strength cast iron), vermicular and flake (malleable cast iron) graphite; depending on the purpose - for structural and cast iron with special properties; according to the chemical composition - alloyed and unalloyed. Classification and properties of cast iron.

Classification of cast iron: 1. By structure: 1) Primary cast iron - white or pig iron (c = 3.7% - 4.5%) Fe 3 C - cementite for producing steel. 2) Gray or cast iron. grade: SCh – 15 Marking of gray cast iron: Letters SCh – (indicate gray cast iron) Numbers – tensile strength, kgf/mm 2; Example SCh – 18 – Gray cast iron, 18 - – tensile strength, 18 kgf/mm 2;

3) Malleable cast iron KCh - 40 - 10, KCh 40-20 Marking of malleable cast irons: Letters KCh - (indicate ductile cast iron) Numbers - (1 - number - tensile strength, kgf/mm 2, 2 - relative elongation, %) Example CN – 35 – 10 - Malleable cast iron, 35 - tensile strength, 35 kgf/mm 2, 10 - relative elongation, 10%)

4) High-strength cast iron ductile iron - 35 Marking of ductile cast iron: Letters ductile iron - (denote high-strength cast iron) Numbers - (1 - number tensile strength, kgf/mm 2, 2 - relative elongation, %) Example HF - 42 - 12 - malleable cast iron, 42 - tensile strength, 35 kgf/mm 2, 12 - relative elongation, 10%)

5) Anti-friction cast iron - obtained on the basis of gray, high-strength and malleable cast irons. Marking of anti-friction cast iron: Letters АЧ– (indicate anti-friction cast iron) Numbers – brand number according to GOST Example AChS – 2, anti-friction gray cast iron, 2 – brand number according to GOST.

X – CHROME; D – COPPER T – TITANIUM M – MOLYBDENUM N – NICKEL Y – ALUMINUM C – SILICON G – MANGANEZ F – VANADIUM 6) Alloyed cast irons are cast irons into which special elements are introduced to improve the properties of cast irons.

ChN 1KhMD – alloyed cast iron, nickel content – ​​1%, molybdenum and copper content – ​​up to 1.5%

What is the name of cast iron in which carbon is contained in the form of cementite? What is the name of cast iron produced by slow cooling? What is spherical cast iron called? What kind of cast iron is converted into steel? What is the name of cast iron obtained by annealing? What is the name of cast iron in which carbon is in the form of graphite plates? What is the name of the cast iron obtained as a result of modification? What is the name of cast iron with graphite in the form of flakes? Which cast iron has high casting properties? Which cast iron has high ductility? Answer form: a combination of the number of the question and the letter of the answer. Answer options: a) gray b) white c) malleable d) high-strength

1.b 2.a 3.d 4.b 5.c 6.a 7.d 8.c 9.a 10.c Answers:

1. Cast iron Transportation of timber along the river 2. Metal The main component of cast iron 3. Non-metal An undesirable component of cast iron Crossword "Association"

4. Alloying additives Alloys of iron with silicon, manganese 5. Alloying element Leather 6. Non-metal in cast iron Component of rock

7. Non-metal Main component of cast iron 8. Alloying element Prominent personality 9. Alloying element Forest

Message: “Cast irons used in mechanical engineering” Learn the classification of cast irons and their markings. Homework.

Goal: to study cast iron Tasks:

Alloys of iron and carbon containing carbon from 2.14 to 6.67% are called cast iron.

Graphitization process.

Forms of graphite: lamellar; globular; flaky; vermicular.

Classification of cast irons

Diagrams of cast iron microstructures depending on the metal base and the shape of graphite inclusions

Application

Application

Application

Bleached and other cast irons Bleached castings are castings whose surface consists of white cast iron, and the inside is gray or high-strength cast iron.

Application Used for the manufacture of rolling shafts, carriage wheels with bleached rims, balls for ball mills. For the manufacture of

Marking of cast iron

Gray cast iron is marked with the letters SCH with the addition of a number that indicates the tensile strength of cast iron. For example: SCh15 SCh – gray

Malleable cast iron is marked with the letters KCH and numbers. The first two digits indicate the tensile strength, and the second relative elongation

Ductile iron is marked with the letters HF and numbers. The first two digits indicate the tensile strength, and the second relative strength

Grades of gray cast iron for castings used in the main branches of mechanical engineering

CONTROL QUESTIONS

Homework

Bibliography

Slide presentation

Slide text: Topic: "Cast irons. Classification of cast irons"

Slide text: 1. Fluidity - the ability of metals and alloys in a molten state to fill the cavities of a casting mold (+) 2. Crystallization is the transition of a metal from a solid state to a liquid state (-) 3. Creep - the ability of a material to slowly and continuously deform plastically.... (+) 4. Malleability - the ability of metals and alloys to be subjected to various methods of mechanical processing and cutting tools. (-) 5. Shrinkage - the ability of metals and alloys to shrink in size after solidification. (+) Blitz survey

Slide text: Cast iron is an alloy of iron and carbon, the carbon content is more than 2.14%.

Slide text:

Slide text: IMPURITIES USEFUL HARMFUL MANGANESIS - increases the hardness of cast iron SILICON - increases strength and toughness, improves casting properties.. SULFUR - reduces strength, worsens casting properties PHOSPHORUS - increases fragility

Slide text: depending on the degree of graphitization, which determines the type of fracture - into gray, white and half (or bleached); depending on the shape of graphite inclusions - into cast iron with lamellar, spherical (high-strength cast iron), vermicular and flake (malleable cast iron) graphite; depending on the purpose - for structural and cast iron with special properties; according to the chemical composition - alloyed and unalloyed. Classification and properties of cast iron.

Slide text: Classification of cast iron: 1. By structure: 1) Primary cast iron - white or pig iron (c = 3.7% - 4.5%) Fe3C - cementite for producing steel. 2) Gray or cast iron. grade: SCh – 15 Marking of gray cast iron: Letters SCh – (indicate gray cast iron) Numbers – tensile strength, kgf/mm2; Example SCh – 18 – Gray cast iron, 18 - – tensile strength, 18 kgf/mm2;

Slide text: 3) Malleable cast iron KCh - 40 - 10, KCh 40-20 Marking of malleable cast iron: Letters KCh - (indicate malleable cast iron) Numbers - (1 - number - tensile strength, kgf/mm2, 2 - relative elongation, %) Example CN - 35 - 10 - Malleable cast iron, 35 - tensile strength, 35 kgf/mm2, 10 - elongation, 10%)

Slide text: 4) High-strength cast iron ductile iron - 35 Marking of ductile cast iron: Letters ductile iron - (denote high-strength cast iron) Numbers - (1 - number tensile strength, kgf/mm2, 2 - relative elongation, %) Example HF - 42 - 12 - Malleable cast iron, 42 - tensile strength, 35 kgf/mm2, 12 - relative elongation, 10%)

Slide No. 10

Slide text: 5) Anti-friction cast iron - obtained on the basis of gray, high-strength and malleable cast irons. Marking of anti-friction cast iron: Letters АЧ– (indicate anti-friction cast iron) Numbers – brand number according to GOST Example AChS – 2, anti-friction gray cast iron, 2 – brand number according to GOST.

Slide No. 11

Slide text: X – CHROME; D – COPPER T – TITANIUM M – MOLYBDENUM N – NICKEL Y – ALUMINUM C – SILICON G – MANGANEZ F – VANADIUM 6) Alloyed cast irons are cast irons into which special elements are introduced to improve the properties of cast irons.

Slide No. 12

Slide text: ChN 1KhMD - alloy cast iron, nickel content - 1%, molybdenum and copper content - up to 1.5%

Slide No. 13

Slide text: What is the name of cast iron, which contains carbon in the form of cementite? What is the name of cast iron produced by slow cooling? What is spherical cast iron called? What kind of cast iron is converted into steel? What is the name of cast iron obtained by annealing? What is the name of cast iron in which carbon is in the form of graphite plates? What is the name of the cast iron obtained as a result of modification? What is the name of cast iron with graphite in the form of flakes? Which cast iron has high casting properties? Which cast iron has high ductility? Answer form: a combination of the number of the question and the letter of the answer. Answer options: a) gray b) white c) malleable d) high-strength

Slide No. 14

Slide text: 1.b 2.a 3.d 4.b 5.c 6.a 7.d 8.c 9.a 10.c Answers:

Slide No. 15

Slide text: 1. Cast iron Transportation of timber by river 2. Metal The main component of cast iron 3. Non-metal An undesirable component of cast iron Crossword "Association"

Slide No. 16

Slide text: 4. Alloying additives Alloys of iron with silicon, manganese 5. Alloying element Leather 6. Non-metal in cast iron Component of rock

Slide No. 17

Slide text: 7. Non-metal Main component of cast iron 8. Alloying element Prominent personality 9. Alloying element Forest

Slide No. 18

Slide text: Message: “Cast irons used in mechanical engineering” Learn the classification of cast irons and their markings. Homework.