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The introduction of steel foundry products (part 2)

Where appropriate, the code draws on relevant parts of existing ILO instruments already, including: occupational safety and health in the iron and steel industry (Geneva, 1983); Safety in the use of chemicals at work (Geneva, 1993); Management issues and drugrelated alcohol in the workplace (Geneva, 1996); Technical and ethical guidelines for workers’ health surveillance (Geneva, 1998); Guidelines on safety management systems and occupational health (Geneva, 2001); Safety in the use of synthetic vitreous fiber insulation wools (glass wool, rock wool, slag wool) (Geneva, 2001); Ambient factors in the workplace (Geneva, 2001); HIV / AIDS and the world of work (Geneva, 2001); and Safety and health in non-ferrous metals industries (Geneva, 2003).

The annexes include information on hazard identification, risk assessment and control and, from relevant ILO instruments, information on workers’ health surveillance, surveillance of the working environment and establishment of OSH management system. As these instruments are updated, the references to them in electronic versions of this code adjusted accordingly. Information on exposure limits and on chemicals used in the iron and steel industry as well. The practical recommendations codes ILO practice intended for the use of all that, in the public and private sectors, responsible for the management of health and safety hazards of occupational specific (eg chemicals, heat, noise and vibration), sectors of activity (eg forestry, mining), or equipment. Not intended Codes of practice to replace national laws or regulations or accepted standards. They are drawn up with the objective of a directive, in accordance with the provisions of national laws and regulations, to all those who may be engaged, through social dialogue, in the framing of provisions of this kind or in programs layout prevention and protection at the national or enterprise levels.

They are addressed in particular to governmental and public authorities, employers and workers and their organizations as well as management and safety and health committees in related enterprises. Codes of practice are primarily designed as a basis for prevention and protective measures and are considered as ILO technical standards in occupational safety and health. They contain general principles and specific guidance which concern in particular the surveillance of the working environment and the health of workers; education and training; record keeping; the role and duties of the authorities, employers, workers, manufacturers and suppliers of competent; and consultation and cooperation. Should the provisions of this code of practice to read in the context of the conditions in the country proposing to use the existing guidance, the scale of operation involved and technical possibilities. In this regard, the needs of developing countries are also included.

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The iron and steel making

For making iron-most, are the essential features of coke ovens and the blast furnace, where coke is produced from coal and iron ore is melted (reduced) to produce pig iron, respectively. The furnace is charged from the top with iron ore, coke and limestone; A hot air, frequently enriched with oxygen, blown in from the bottom; and the carbon produced from the coke transforms the iron ore into pig iron containing carbon, with the generation of carbon monoxide and carbon dioxide. The limestone acts as a flux. At a temperature of 1,600 ° C, the pig iron melts and collects at the bottom of the furnace. The furnace is tapped (ie the pig iron is removed) periodically, and pig iron is cast into pigs for later use (eg in foundries), or is poured into ladles where it is transferred, still molten, to the steel making plant. The waste gas from the blast furnace, which is rich in carbon monoxide, burned in blast furnace stoves to heat the air blown into the furnace and may be used as a fuel elsewhere in the steel plant.

Some pig iron is also produced in foundry cupola furnaces. Various processes exist or are under development for producing iron through the direct reduction of iron ore, using reducing gases. Such processes may be more important in the future.
The purpose of operations aa steel refine the pig iron which contains large amounts of carbon and other impurities. The need to reduce carbon content, the impurities oxidized and removed, and the iron converted into a highly elastic metal that can be forged and fabricated. Alloying agents may be added at this stage. Different types of melting furnace used in this process.

Some steel is produced directly from scrap or other materials containing iron, most often in electric arc furnaces, without the need for iron ore or coke.

Steel is cast into slabs, billets, bars, ingots and other shapes. A scarfing, pickling, annealing, hot and cold rolling, extrusion, galvanizing, surface coating, cutting and slitting, and other operations designed to produce a variety of steel products including subsequent steps.

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The application of iron and steel foundry industry

This code of practice should provide guidance, in accordance with the provisions of the laws and national regulations, to:
(a) all those government authorities, associations of workers and employers organizations and industry, whether legislative or advisory, whose activities influence the safety, health and welfare of workers in the iron and steel industry;

(b) all persons at the iron- and steel-making facilities, ie employers, persons in control of premises, and workers and contractors, as appropriate to their duties and responsibilities for safety and health;

(c) all operations in the iron and steel industry.

OSH can implement some measures of health and safety to protect workers in the iron and steel industry would be affected, directly or indirectly, on the general environment. This relationship should be taken into account by the competent authorities and employers both in design and their respective policies and programs to implement.

Should the provisions of this code at least consider. It is not intended to replace the laws, regulations or accepted standards laying down higher requirements. Priority should be stricter requirements applicable beyond the provisions of this code. In the absence of laws and regulations on national OSH particular issue, should draw guidance from the code of practice, as well as other relevant instruments are recognized nationally and internationally. 1.2.4. References to the institutions responsible for the delivery and award of vocational education the code. Such institutions are advised to review existing curricula in the light of the recommendations of the code for training and allocation of responsibilities at work.

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The objectives of iron and steel foundry industry

This code of practice, which is a review of the one adopted in 1981, should be:

(a) to protect workers in the iron and steel industry from workplace hazards and to preventing or reducing injuries and related diseases work, ill health and incidents;

(b) to facilitate questions and help better manage occupational safety and health (OSH) in the workplace;

(c) effective consultation and cooperation between governments and organizations of employers and workers to promote improvement of OSH in the production of iron and steel.

The code of practice should assist in:

(a) a coherent national policy and principles of safety and health and welfare of workers in iron- and steel facilities and for general environmental protection work to establish trade;

(b) establishing the duties and responsibilities of the authorities, employers, workers and others involved respectively and arrangements for structured cooperation between making;

(c) improving knowledge and competence;

(d) promote the implementation and integration of OSH management systems in line with the expected improvement of working conditions.

The code of practice provides practical guidance on the role and obligations of competent authorities and the responsibilities, duties and rights of employers, workers and all other parties involved, in connection with workplace hazards. In particular it covers:

(a) the establishment of legal frameworks, administrative and effective prevention and reduction of hazards and risks;

(b) the aims of any mechanisms for identifying, eliminating, minimizing and controlling hazards;

(c) the assessment of risks and hazards to the safety and health of workers and the measures that need to be taken;

(d) surveillance of the working environment and health of workers;

(e) emergency procedures and first aid;

(f) to provide information and training for workers;

(g) to establish a system to record, report and monitor accidents and occupational diseases and dangerous occurrences.

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The introduction of steel foundry products (part 1)

In accordance with the decision taken by the Governing Body of the ILO at its 288 session in November 2003, held a Meeting of Experts on Safety and Health in the Iron and Steel Industry in Geneva from February 1 to 9 of 2005 to draw up and adopt a revised code of practice on safety and health in the iron and steel industry. The meeting was composed of seven experts appointed after consultation with Governments, eight experts appointed after consultation with ‘group and eight experts appointed after consultation with the Workers’ group of the Governing Body of Employers. Adopt original code of practice on safety and health in the iron and steel industry at a meeting of experts in 1981.

This new code, which reflects the many changes in the industry, its workforce, the roles of the competent authorities, employers, workers and their organizations, and the development of new ILO instruments on occupational safety and health focuses on the iron and steel and iron and steel basic products, such as rolled and coated steel, including from recycled content. It does not deal with the mining of raw materials for iron and steel production, which is covered by the Safety and Health in Mines Convention, 1995 (No. 176), and codes of practice on safety and health in coal mines (1986) and safety and health in surface mines (1991), nor does it deal with the fabrication of commercial steel products. The code of conduct is based on principles established in international instruments relevant to the protection of workers’ safety and health.

The first two chapters deal with the objectives and implementation of the code. The next two chapters address, within a national framework, the responsibilities, duties and rights of the competent authority, the labor inspectorate, employers, workers and their organizations, suppliers, manufacturers and designers, and contractors, and occupational safety and health (OSH ) management systems and services and OSH reporting. Part II of the code addresses different operations commonly used in the production of iron and steel – from coke ovens to steel furnaces and foundries, to rolling mills, coating lines and recycling. It also covers transport, competence and training, personal protective equipment, emergency preparedness, and special protection issues and hygiene. Each section describes hazards, risk assessment and provides guidance on eliminating or controlling risk.

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Sand testing of sand casting (4)

7) Shatter Index Test :

In this test, the AFS standard sand specimen is usually rammed by 10 blows and then it is allowed to fall a half inch mesh sieve from a height of 6 feet. The weight of sand retained on the sieve weighing. It then notified as a percentage of the total weight of the specimen is measured on the index shatter.

8) Mold Hardness Test:

The test is performed by mold hardness tester. The work on the tester based on the principle of Brinell hardness testing machine. In AFS hardness tester is a standard half-inch diameter steel ball hemispherical spring loaded with a load of 980 gm. The ball has to do to break into the sand mold or core sand surface. The spot is the point ball into the mold surface shown on dial in thousands of inches. The dial is calibrated to read the mold surface hardness directly ie offering no resistance to the steel ball hardness value would be zero and more rigid model and fully capable to prevent the ball from penetrating steel would hardness value of 100. The gauge can dial the hardness tester to provide direct readings.

9) Compactability flowability :

Compactability test is widely accepted as both a simple and directly related to the transport of sand in shape, especially when associated with compaction squeeze. A fixed amount of loose sand compacted under standard conditions and shows the percentage reduction in the amount of compactability.

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Sand testing of sand casting (3)

5) Strength test:

This is tempered sand strength expressed by its ability to hold model in shape. Sand molds are subject to compressive, tensile, shearing and transverse stress. The compressive strength test green and dry compressive strength of the test most commonly used in the foundry.

- Compression Tests A specimen of sand rammed produced Tempered shape is 2 inches in diameter and 2 inches tall. The sample is then rammed subject to load increase gradually until the sample breaks. The point where the sample taken breaks the compression strength.

- Shear Tests compressive loading system is modified to offset the specimen load to provide. Under most conditions the shear test results shown to be closely associated with the compression tests, although the latter property increases proportionately more high density ramming.

- The tensile test specimen is loaded in tension special waisted by a pair of grips. The test sample is rectangular plain transverse support by the end of knife edges and centrally loaded broken. And transverse tensile tests commonly applied to sand high strength, the conditions to be particularly associated with the stress incurred during handling cores and solutions.

6) Permeability Test:

Permeability is determined by measuring the air flow rate through compacted specimens under standard conditions. Roller sand sample is prepared using rammer and death. This sample (typically 2 inch dia and 2 inches tall) used for testing the permeability or porosity of the sand molding and core. The test is performed in permeability meters flat consists of a tank, water tank, nozzle, lever, adjusting the nose piece for fixing sand specimens and a manometer. The permeability is measured directly. Permeability number P is air volume (in cm 3) passing through sand specimen of 1 cm2 area and 1 cm cross-sectional height, a pressure difference of 1 gm / cm2 in one minute.

P = VH / ATP

Where,
P = permeability
v = volume of air passing through the specimen in c.c.
h = height of specimen in cm
p = pressure of air in gm/cm2
a = cross-sectional area of the specimen in cm2
t = time in minutes.

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Advantages and Disadvantages of Sand Casting

Advantages of sand casting:

1) solutions can be used to create complex geometries pad, including internal Goth external shapes arid.

2) Some parts casting operations produce net shape. Any additional manufacturing parts are needed.

3) can be used solutions.

4) casting process for any metal that can be heated to the liquid state.

5) There are several methods highly suitable solutions to this mass.

6) Resolution is the easiest and fastest (technique) from drawing (design) production.

Disadvantages of Sand Casting:

1) Limitation on mechanical properties.

2) Porosity (empty spaces inside the metal – metal strength decreases).

3) Poor precision dimensional and surface finishing.

4) safety hazards for people and environmental problems. A very difficult

5) Ending pattern of thin and small parts.

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Automated Sand Casting in Foundries

Today 70% of the processes to achieve solutions to automation. It is because of upto 200 sand casting components ideal, but in the case of long production lines arid higher number of components not much arid little economic sand casting components. For this purpose automated foundry is the right choice. High temperature melting metal used for castings. There are three types of producing

1) factory jobbing upto 100 parts but many of the

2) 500-1000 Batch factory part.

3) Mass production: lots of parts, can be more than 1000.

In foundries are automated conveyor continuously pouring into the pre-made models. This process is ongoing two levels.

1) Pooring the continuous metal into the molds.

2) Charges metal into the tables from the furnace (iron gray mostly) (all tables have six tones)

In automated sand casting sand automatically made arid pattern is made of metal. More water is added to the sand. But riot have become too damp sand otherwise it disintegrates easily. The pattern is pressed into the sand prepared by automatic hydraulic press and the mold is made. By the same procedure many models made then start operation solutions without stopping conveyor After the castings have cooled down arid completely, models have destroyed them passing through the drum recycling rotating sand removed arid up again with the sand transport system and the solutions have moved in the drum for additional operations such as the removal of the parts over (risers runner arid) from their bodies, and finishing operations arid burst. For a small number of large casted components with high melting temperature, metal, sand casting is suitable But this is a disadvantage every time you need a new model so that the technique would be economic for metals riot low melting temperature.

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Sand casting is simply melting the metal and pouring

Casting off the old technique is the quickest link Between 2nd manufacturing engineering drawing .It Provides us with the possibility of forming wide range of shapes with wide range of materials. sand casting is simply Melting the metal and pouring it INTO a preformed cavity, Called mold, allowing (the metal to solidify and Then breaking up the mold to remove casting. In sand casting expandable molds are Used. So for each casting operation are i have to form a new mold. Basic Requirements for metal casting

1. A mold cavity
2. Melting process
3. Pouring technique
4. Solidification process
5. Removal of casting
6. Finishing draft allowance.

Sand Casting is the MOST important ‘and mostly Cars casting technique. To Perform sand casting we do i have to form a pattern (a full sized model of the part), enlarged to account for shrinkage and machining allowances in the final casting. Materials Used to Make Patterns Include wood, plastics, aluminum, fiberglass, cast iron and Some other metals. Wood is a common pattern material Because it is easily. Worked INTO shape. Its disadvantages are That it tends to warp and the sand Being compacted around it abrades it, setup Limiting the number of times it whence be reused (Used for a small number of castings). Metal Patterns are more expensive to Make, BUT not * Much longer cargo. For example aluminum is the MOST common metal to be Used in f “work schedule castings are to be made by the Same pattern. So selection of the Appropriate pattern material depends to a large extent on the Total Quality of castings to be made. The size of the pattern depends upon the shrinkage Düring cooling and the Finishing allowance. Some special coating to Prevent Their Destruction shouldnt coat Patterns. Patterns i ar Some identifiers thrown out colors on dis, each of Which DG Different Meaning That represent Different treatments and requirements Far the Patterns. The casting will be Missing. To ensure That cores retain the Correct arrangement core Prints are placed Into the mold. Some metal springs Called densiments are placed Into the mold Io Provide Uniform solidification of the metal throughout the mold. Nails are inserted INTO thin parts of the mold to reinforce dis. After forming the mold cavity, the liquid is sprayed Alcoholic aver the cope (The upper part of the mold) and heated with flames to harden and to dry the surface.

Filling a metal box Having two halves, Which is Called the flask mold forms. So ar mold made up of two halves, Which is separated by a parting line. The Reason for this is to remove the part tasted easier for from the mold. The upper part of the mold Called the cope and the lower part Called the drag. The cope and drag are prepared separately and are ready not * not * When unites and metal is poured through a canal it INTO Called sprue, Which transmits the molten metal via Into the mold cavity runner. The runner shouldnt be big Because it will Increase the Amount of the waste metal. It shouldnt be small Because this enhances rapid solidification in the runner causing a blockage. At the bottom of the sprue there is a gap Far well Called the collection of the unwanted sand, Which comes with the flowing metal. There ar a riser system, Which acts from the inventory of molten metal When the mold cavity is fulfilled with the metal and Automatically feeds the cavity of the part I want to Get That we do.

Because this system is Essential for the molten metal cools it down this shrinks the Amount Needed to Replace the metal shrinked Comes fom the riser itself eliminating shrinkage cavities. A casting microporosity May show. This sing with directional solidification be eliminated either by incorporating a metal cell Into the mold or by tapering the thinnest section of the runner. You Chills ar Used around thicker parts of the casting to Provide Uniform cooling of the cooler parts These thinner parts to Prevent cracks. Chills, by this way, preserve the mechanical properties of the casting siar. The steel is melted in electric-arc Furnaces. The Advantage of electrical furnace, the scrap steel, Which wasnt Used Estimates for (metal risers and runners left In) sing in These Furnaces be melted and used again. When the furnace reaches the drink to temperature, it is Turned off. The molten metal is Filed Portable RESERVOIR Called Into the table and Then table is moved to just Above of the mold and metal is poured Into the mold’s pouring basin. A powder is added to the mold’s surface to Prevent metal’s rapid cooling pouring Düring. Another powder is sprayed aver the mold to form a blanket of inert gas to Prevent the oxidation of the molten metal. The steel is melted in electric-arc Furnaces. The Advantage of electrical furnace, the scrap steel, Which wasnt Used Estimates for (metal risers and runners left In) sing in These Furnaces be melted and used again.

When the furnace reaches the drink to temperature, it is Turned off. The molten metal is Filed Portable RESERVOIR Called Into the label and Then table is moved to just Above of the mold and metal is poured Into the mold’s pouring basin. A powder is added to the mold’s surface to Prevent metal’s rapid cooling pouring Düring. Another powder is sprayed aver the mold to form a blanket of inert gas to Prevent the oxidation of the molten metal. Completed The casting is left for cooling and When it completely cools down the siar flask is wrangled to a vibrating platform to remove the casting from the mold. Excess parts are cut either by oxygen in f the casting is of steel (high), or by hammering in f the casting is of cast iron.

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