casting methods. The essence of foundry. Casting methods Modern methods for increasing the efficiency of foundry production


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§ 5. Ways to improve the quality of castings

Improving the quality of castings is ensured by carrying out a whole range of organizational and technical measures in the foundry.

The composition of the molding sand is important for improving the quality of manufactured castings. Providing the site with high-quality raw materials, supplying the recycled mixture to mixers in a cooled state, high-quality separation and screening of the used mixture, accurate dosing of components, in particular the binder, have a positive effect on improving the quality of castings. Of great importance is the well-established regular control of the properties of molding materials in the workshop laboratory and, first of all, the control of strength and gas permeability.

The quality of castings also depends on the state of the technological equipment. Wooden model kits are warped, with cracks do not contribute to the achievement of dimensional accuracy. Warping of flasks during the manufacture of molds, especially large ones, is unacceptable; this leads to a redistribution of loads in the parting plane, collapse of the mold, and leakage of metal from it.

Compaction of the mold must be carried out strictly in accordance with the technical instructions. In the manufacture of large molds, it is advisable to use cold-hardening and liquid mixtures that do not require compaction. Low surface roughness of castings is ensured by the use of non-stick mold coatings.

Of great importance for obtaining high-quality castings is the continuous improvement of the skills of the brigade molders at various courses.

It is important to have well-organized control over the performance of all operations for the manufacture of casting molds in the workshop, to correctly follow the instructions of technological instructions, and to improve sanitary and hygienic working conditions.

The introduction of the latest achievements of science and technology, the improvement of the culture of production in the foundry are an indispensable condition for the production of quality products.

test questions

1. Name the features of the formation of castings.

2. Tell us about the methods of quality control of molds, cores used in the foundry.

3. List the casting defects that occur during manual molding.

4. Name the activities that improve the quality of castings.

Technology system machine-building plant

Topic 11. Fundamentals of mechanical engineering technology

Lecture plan

11.1. Technological scheme of a machine-building plant

11.2. Essence foundry. Casting methods

11.3. Metal forming methods (rolling, drawing, pressing, forging, stamping)

11.4. The essence of the build process

11.5. Types and organizational forms build process

11.6. Ways to Improve Build Efficiency

Mechanical engineering is the leading branch of modern industry. The importance of mechanical engineering in the national economy is determined by the fact that it creates one of the most important elements of the productive forces - the tools of labor. Due to the variety of tools of production and the social division of labor, mechanical engineering is divided into separate branches, of which the main ones are: machine tool building, heavy engineering, transport, energy, agriculture, and nuclear.

Each branch of engineering has its own specific technological methods and techniques, however, in general, mechanical engineering is characterized by a commonality of raw materials (ferrous and non-ferrous metals, their alloys and the identity of the basic technological principles for turning them into parts (casting, forging, stamping, cutting), and parts into a product (welding, assembly).

In the production processes of mechanical engineering, the basic principles are used rational organization production.

At machine-building plants, the following main workshops :

v procurement: iron foundry, steel foundry, forging and pressing;

v processing: mechanical, thermal;

v producing products: assembly.

Organization industrial production built according to one of the principles - technological, subject or mixed. The above division of the main workshops is inherent in the technological principle of the organization of production. With the objective principle of organizing production, equipment for the manufacture of specific parts or assembly units is concentrated in separate workshops of the enterprise. With a mixed principle - in separate workshops, technologically homogeneous parts are processed and the same type is performed. technological processes and operations.

Otherwise, the structure of machine production is not much different from other industries, i.e. there are auxiliary workshops and side workshops, various services and facilities, enterprise management bodies that organize the production process and control it, ensure the development of technical documentation and technological equipment, accounting, and marketing of finished products.

Thus, a machine-building enterprise is a set of a number of industries connected by a single technological process. Depending on the scale of production, the possibilities of cooperating with other enterprises, and a number of other technical and economic conditions, the machine-building plant either carries out the entire technological process itself, i.e. manufactures all parts of the machine and assembles it, or manufactures only the main components of the machine, and receives parts and semi-finished products (castings, forgings) from other specialized enterprises and only processes them and then assembles them in its workshops. The technological scheme of the machine-building plant is as follows: raw materials and fuel from the charge yards, where they are stored and properly prepared for production, go to foundries that produce castings. The resulting casting is sent to the machine shop, where the blanks made by forging and stamping in the forging and pressing shop also come. In the mechanical workshop, further processing of blanks is carried out by cutting on various metal-cutting machines. In addition to processing cast and forged blanks, metal-cutting machines produce parts from rolled products. Parts that require heat treatment are sent to the heat shop.


Finished parts from machine shop are sent to the assembly shop, where the finished parts of their other shops arrive. Mechanical and assembly shops are often located in the same building, which reduces the cost of intra-factory transportation of parts and assemblies. The most common processes in mechanical engineering are casting, rolling, drawing and pressing, forging, stamping, welding, machining processes (cutting).

Foundry called the processes of obtaining shaped products (castings) by pouring molten metal into the resulting form, reproducing the shape and dimensions of the future part. After the metal hardens in the mold, a casting is obtained, i.e. workpiece or part.

In the structure of the cost of casting, the main share is the cost of metal (up to 80%). Making a technical and economic analysis of foundry production, Special attention it is necessary to pay attention to those stages and elements of the technological process that are directly related to possible metal losses due to waste, spatter, rejects, etc. The cost of casting depends on the volume of production, the level of mechanization and automation of technological processes.

With all the variety of casting techniques that have developed over a long period of development of its technology, the basic scheme of the casting process has not changed much and includes 4 main stage :

1. Metal melting.

2. Making molds and cores.

3. Pouring liquid metal into a mold.

4. Extraction of the hardened casting from the mold.

Advantages foundry:

v the possibility of obtaining complex thin-walled castings with the rational use of metal;

v low cost of production;

v relative ease of obtaining castings.

disadvantages foundry:

ü low labor productivity;

ü heterogeneity of the composition and reduced density of the workpiece material.

There are the following casting methods:

◭ casting in disposable sand-clay molds (earth);

◭ mold casting (permanent metal molds);

◭ injection molding;

◭ centrifugal casting method;

◭ investment casting;

◭ shell casting or cork casting;

◭ casting into thin-walled one-time molds;

◭ electroslag casting.

All of the above casting methods, except earth casting, are called special casting methods. Castings are widely used in mechanical engineering, metallurgy, construction.

The most common and relatively simple way casting - casting into disposable sandy-clayey forms. Up to 80% of castings are obtained by this method. Sand-clay molds can be prepared either directly in the soil (in the floor of the foundry) according to templates, or in special flask boxes according to models. Large castings are made in the soil, small ones are made in flask molds.

The technological process for the production of castings in flask molds consists of three stages: preparatory, main (Fig. 11.2.1) and final.

The preparatory stage includes the design and manufacture of pattern equipment.

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UDC 621.74

MODERN FOUNDRY TECHNOLOGIES

B. S. Glazman

Don State Technical University, Rostov-on-Don, the Russian Federation

UDC 621.74 MODERN FOUNDRY TECHNOLOGIES

Don State Technical University Rostov-on-Don, Russian Federation

The technologies for manufacturing castings, methods of automation of foundry production, the composition of foundry conveyors, the use of a protective coating to improve the quality of manufactured products are considered.

Keywords: foundry, castings, chill mold, chill conveyor, molding, molding line

The article considers the technologies of making castings, methods of automation of foundry production, the composition of foundry conveyors and the application of protective coatings to improve the quality of manufactured products.

Keywords: foundry, castings, shell mold, permanent mold conveyor, block mold, block mold conveyor, forming, molding line

Introduction. Foundry production is one of the main procurement bases of mechanical engineering. Foundry production has a high metal utilization rate - 75-95%. Russia ranks third in the world in terms of the total production of cast billets after such large manufacturing countries as China and the USA.

Numerous casting methods are used in the industry. To increase labor productivity, they strive to use mass production, full mechanization and automation of foundry production.

Casting technologies. At present, in the manufacture of castings by molding, molding lines and pouring machines are used, which make it possible to produce a large number of molds with high accuracy with a small number of attendants.

Fig.1 Molding line HWS: 1,4,11 - plate; 2 - rack; 3 - clamp; 5,9,10,12,14 - guide; 6.8 - mount; 7 - disk; 13 - bushing; 15 - clamp.

Rice. 2 General form automatic molding line Disa

The Disa molding line includes a shuttle-type sandblast molding machine that pulses the flaskless molds onto the conveyor. In the pouring section, the automatic pouring unit (5) fills the molds with the melt. Then the castings are cooled and transferred to a cooled knockout drum, where the castings are separated from the mixture, lumps are crushed, and the mixture and castings are finally cooled. The next step is the homogenization of the circulating mixture, which enters the syringe for the final preparation of the mixture and into the mixer, where it is transferred with refreshing materials and a high-ranking mixture is obtained. The resulting mixture is transferred to the molding machine.

Castings enter the shot blast machine (4) through an adapter (3) for surface treatment. Then the painting, quality control and warehousing operations take place.

Currently used in industry special methods casting, for example, die casting. This method allows to obtain more precise castings with stable dimensions. The minimum physical and chemical interaction between the casting metal and the mold contributes to the improvement of the quality of the casting surface, the absence of burn marks. Heat is quickly removed from the casting, which leads to its rapid hardening and provides an increase in mechanical properties.

Mechanization and automation of the technological process of mold casting provides an increase in labor productivity, stability of technological regimes, improvement in the quality of the casting and an increase in the economic efficiency of the production process.

On the industrial enterprises chill conveyors are used. On the trolleys of a horizontally closed conveyor, a mold is installed for one or more different castings, which is an indicator of the productivity of foundry equipment.

Fig 3. Rotary chill machine: 1.2 - plate; 3 - shaft; 4 - pusher.

Rice. 4. Vertically closed mold conveyor: 1 - wheel; 2,3 - chain; 4 - tray; 5 - box;

6 - nozzle; 7 - spray gun; 8 - tank; 9 - transmission.

In the mold mold of the conveyor (Fig. 4), the cover opens automatically, and the castings from the mold through the tray (4) fall into the box (5). On the lower branch of the conveyor, open molds are cooled by air from nozzles (6), then painted with a spray gun (7) from a tank (8).

The main operations of mold casting are the opening of the mold, the extraction of cores and castings, the application of a refractory coating, the installation of cores, the locking of the mold, the pouring of the melt. All operations are performed by the mechanisms of a chilling machine or a foundry complex, which is controlled by a worker-operator. When automating the chill conveyor, the mechanisms are controlled by a computer.

In serial and small-scale production of large castings of complex configuration, the use of automated chill molds is effective. In mass and large-scale production of small and medium-sized castings - automatic foundry complexes and automatic lines.

Fig.5 Schemes of automated foundry complexes for mold casting: a - for complex castings; b - for simple castings.

Figure 5a shows an automated casting complex for complex castings. The melt from the dispenser (1) is poured into the mold (2). Sand cores from the magazine (4) are installed in the mold with a manipulator (3). After hardening and opening of the mold, the castings are removed by the manipulator (6) and fed into the press (8) to harden the gating system.

Finished castings fall into the container (7), and then are transported along the conveyor (5) for processing. The melt from the melting units is fed into the dispenser along the monorail (9) by ladles. Manufacturing process operated by operators.

On fig. 4b shows an automated casting complex for simple castings. The melt from the dispenser (1) is poured into the molds installed on the machines (2). After the casting hardens and the mold opens, the casting is removed by the manipulator (4) and transferred to the container (3). The complex is controlled by the operator from the remote control.

In mass and large-scale production, specialized lines are used, designed both for the manufacture of one casting, and several castings of the same type.

Such lines include melting units, vehicles for filing

melt to loading devices, units for processing castings, vehicles for waste disposal, equipment for cleaning castings, installations and devices for quality control of castings. The lines are characterized by high performance and energy efficiency.

Fig.6 Scheme of an automated control system for the casting process

under pressure by computer

Figure 6 shows a diagram of an automated control system for the technological process of injection molding using a computer.

Automated system functions as follows. The signals from the parameters of technological processes (T) are sent to the switches (K), and then to the ADC and then to the control computer serving all the injection molding complexes. The casting quality control system (QCS) sets the numerical values ​​of the functions of quality indicators (T) from the parameters of the technological process (objective function) and transmits the computer through the switch K3 and ADC3. computer based program and mathematical model technological process, linking the objective function, constant and variable (adjustable) parameters of the injection molding process, produce optimal values ​​of the adjustable parameters. Through the feedback system, including the switch K2 and ADC2, the control signal is transmitted to the system of regulators (p), which act on the actuators of the casting machine.

The operation of casting machines and units takes place under heavy loads and various levels of temperature, in aggressive environments and vacuum.

Used in industry various methods coatings using a variety of materials (metals, alloys, ceramics, plastics), as a result of which the physicochemical state of the surface layer of the workpiece differs from the main material of the part. These include surfacing and sputtering, electrolytic and chemical coatings, coatings with polymeric materials.

The galvanizing method is widely used in enterprises. The galvanizing process is carried out by vibration processing, which is fully automated. The method of electroplating is also widely used, providing a high quality of the surface of the product.

Conclusion. Automation of foundry production using modern technologies and equipment increases the level of productivity of enterprises, the competitiveness of manufactured products and the efficiency of the industry as a whole.

Bibliographic list.

1. Gini, E. Ch. Technology of foundry production. Special types of casting / Gini E. Ch., Zarubin A. M., Rybkin V. A. - 3rd ed., Moscow: Academy, 2008. - 352 p.

2. Glazman, B. S. Automated and robotic casting. Finishing casting / B. S. Glazman // Monograph. - Rostov-on-Don: DSTU Publishing Center, 2014. - 88 p.

CONFERENCES SEMINARS EXHIBITIONS 121

IMPROVING TECHNOLOGY AND INCREASING THE EFFICIENCY OF FOUNDRY PRODUCTION

The scientific and practical seminar "IMPROVING TECHNOLOGY AND INCREASING THE EFFICIENCY OF FOUNDRY PRODUCTION" was held on October 7-10, 2008 within the framework of the XII International Forum "Russian Industrialist".

The forum brought together industrialists and entrepreneurs from many regions of Russia, as well as representatives of countries near and far abroad. Every year this seminar becomes more and more representative, and its program is supplemented by the most relevant topics and directions that meet the requirements and requests today. The forum is one of major events in the calendar of business life in St. Petersburg and throughout Russia.

In 2008, the agenda of the forum included a discussion of the most important issues related to the implementation innovative technologies development of small business. In the address of the Governor of St. Petersburg V.I. Matvienko to the participants and guests of the International Forum "Russian Industrialist" it was noted that its subject matter fully meets the interests of the city (metropolis), the objectives of its industrial policy, aimed competitive world-class products.

An important event included in the program of the event was the holding of a scientific and practical seminar "Improving technology and increasing the efficiency of foundry production", which was held under the scientific guidance of prof., Dr. tech. Sciences Tkachenko Stanislav Stepanovich - President of the Association of foundry workers of St. Petersburg.

The seminar was attended by specialists in the field of foundry and metallurgy: FGUTT "PA" Oktyabr", OJSC "Rostvertol", OJSC "NPK "Ural-Vagonzavod", CJSC "Kazan Giproniyaviaprom", CJSC "Tekhnologiya-M", OJSC "BiKZ ”, OJSC GPNII-5, OJSC AK OZNA, Polygon LLC, KomMod, Escalada, Rontal-Impex, SevZapEnergo, TsNIIM, as well as the State Polytechnic Institute (Technical University), Department of "Automation of technological processes and production" of the St. Petersburg State Mining Institute ( technical university) and etc.

A number of reports at the seminar aroused particular interest of the participants: “New materials and foundry technologies (G.A. Kosnikov, GPTU), “Computer analysis of foundry technology - problems and prospects” (V.M. Golod, GPTU), “Foundry aluminum alloys and technologies for obtaining high-quality castings from them "(A.A. Abramov, TsNIIM),

“Complex modifiers for steel casting” (N.V. Ternovy, KomMod), “Polygon” computer modeling system (E.A. Ishkhanov), “ Modern technologies iron casting" (S.S. Tkachenko, State Pedagogical University), "The experience of an enterprise in improving the technology of injection molding" (S.L. Samoilov, "Escalada"), "New foundry steels and technologies for obtaining high-quality castings from them" (G. A. Shemonaeva, TsNIIM), “Modern technologies of titanium casting” (A.M. Podpalkin, TsNIIM), “Computer analysis of model casting technology and the use of exothermic materials to improve the quality of castings” (D.A. Lukovnikov, Rontal-Impex ”), “Casting technologies using vacuum-film molding” (V.D. Ryabinkin, TsNIIM), “Experience in the manufacture of pattern equipment” (T.N. Gavrilova, SevZapEnergo), “Possibilities of using modern eddy current flaw detectors” (M.Yu. Koroteev, “Constant”), etc.

On October 9, an off-site meeting was held at the Contact Network Fittings Plant, where the problems “Production of investment casting” and “Production of casting using gasified models” (A.A. Lisova) were discussed.

On the final day of the seminar on October 10, an exchange of experience took place on the considered problems of foundry production and a discussion of the speeches of the seminar participants.

In the decision of the seminar, it was noted that the main procurement base of machine building is foundry production, the development of which depends on the level of the machine-building complex as a whole. The machine-building complex of Russia includes about 7,500 enterprises. The share of mechanical engineering in the total industrial output is about 20%, including 2.5% of machine tool and instrument making.

At present, there are about 1,650 foundries in Russia, which, according to expert estimates, produced 7.68 million tons of castings in 2006, including 5.28 million tons of cast iron, 1.3 million tons of steel, from non-ferrous alloys - 1.1 million tons.

In 1980, in the USSR, the volume of production of castings from alloys of ferrous and non-ferrous metals amounted to 25.8 million tons. - Is the technical potential (capacity) more than 2 million tons? During this period, foundries out- | advanced technological processes of melting, 5 shaping, finishing operations were used. In the foundry

122 CONFERENCES SEMINARS EXHIBITIONS

about a dozen research institutes of all-Union significance worked in production. The Minstankoprom produced 70,000 metal-cutting and 20,000 forging and pressing machines.

The volumes of production of cast billets are in proportion to the volumes of production engineering products, since the share of cast parts in cars, tractors, combines, tanks, aircraft, etc. is 40-50%, and in metal-cutting machines and press-forging equipment it reaches 80% of the mass and up to 25% of the cost of the product.

A sharp decline, since the 1990s, in the production of metal-cutting, woodworking machines and forging and pressing equipment, as well as power equipment for heavy engineering, shipbuilding, tractors, military equipment and others, led to the fact that the production of castings in Russia decreased from 18.5 million tons in 1991 to 4.85 million tons in 2000. Specialized centrolite plants for machine tool building with a total capacity of about 1 million tons of castings per year, created in the 1970s, could not stand the competition, lost orders and practically ceased their activities. Foundries working on the surviving mills

construction plants, in 2006 produced (according to expert estimates) 190-195 thousand tons of castings for own production and external customers.

A rather complicated situation has developed. If orders for machine tools now appear, foundries will not be able to produce high-quality, competitive castings, and none of the remaining foundries can produce castings weighing more than 30 tons. There are almost no highly qualified foundry specialists left in the industry, both workers and engineers, and most of the research institutes have been liquidated.

There is an urgent need for reconstruction of foundry shops, which should be carried out on the basis of new, environmentally friendly technological processes and materials, progressive melting, mixing-preparation and shaping equipment, ensuring the production of high-quality castings that meet European and world standards.

S.S. Tkachenko, I.N. Beloglazov

St. Petersburg State Mining Institute (Technical University)

HN>UU fcxrnuSiOft ihOuSTl

Official representative of Aluminco s.a. in Russia, EvrAzMetall-Center

ALUMINCO S.A. formed in 1982 in Greece. During its existence, it has become one of the largest companies in Europe in the area aluminum production. It supplies its products to more than 60 countries of the world. The production capacities of the company allow to produce up to 7000 tons of aluminum profiles per year, up to 1000 tons of aluminum castings, up to 50000 pieces. aluminum sandwich panels.

The production and technology group includes:

extruder with a capacity of 7000 tons of profiles per year; Foundry;

painting line with preliminary anodizing; sandwich panel production line; bending line;

assembly shops;

tool line for the production of matrices; design department; design studio.

Product quality is noted ISO certificates 9001, QUALICOAT and BUREAU VERITAS. ALUMINCO S.A. campaign products:

7 profile systems designed for the manufacture of windows, doors, facades, office partitions, etc., in various combinations, which can work in both hot and cold climates, with various wind loads;

door aluminum sandwich panels of about 1000 different configurations, intended for use both for internal and external doors;

cast aluminum gratings; gates and wickets made of cast aluminum; Street lights; outdoor and garden furniture; visors over entrance doors; stair railing;

small architectural forms (columns, pylons, cornices, ports, etc.).

In 1996, for the first time in Russia, elements of decorative design of internal facades were used during the construction of the Okhotny Ryad shopping center on Manezhnaya Square.

Subsequently, the products of ALUMINCO S.A. were used in the construction of various shopping centers, residential buildings, settlements and other urban and social facilities.

Our website: www.aluminco.ru

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