Steel.docx

HOW TO REDUCE THE COST OF STEEL FABRICATION Submitted in partial fulfillment of the requirements for the award of BACHELOR OF TECHNOLOGY IN Mechanical Engineering By NAME

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Under the Guidance of

SRMUNI Affiliated to U.P TECHNICAL UNIVERSITY LUCKNOW

Table of Contents 1 Objective: ...........................................................................................3 2 Introduction: .......................................................................................3 2.1 How is steel made: ........................................................................4 2.2 How many types of steel are there? .............................................5 2.2.1 Contemporary steel: .............................................................5 Carbon steels .................................................................................5 Alloy steels ....................................................................................6 2.3 Standards.......................................................................................7 2.4 How much steel is produced in a year? ........................................7 2.5 What is smart manufacturing? ......................................................7 2.6 Is steel environmentally friendly and sustainable? ......................8 2.7 Can steel be recycled? ..................................................................8 2.8 Why does steel rust? .....................................................................9 2.9 Uses ...............................................................................................9 3 Literature Review .............................................................................10 2.11 Material properties ......................................................................12 Heat treatment ............................................................................16 4 Understanding the Cost of Materials in the Steel Industry ..............17 5 Various methods to reduce the cost of steel fabrication ..................18 6 The Main Objectives and Strategies of Manufacturing ...................21 7. Advantages of Steel .........................................................................23 8. Disadvantages of Steel ....................................................................24 9. Future Scope ....................................................................................25

1 Objective: Companies are always looking for ways to increase profits and decrease spending. But it is extremely important to save money where you can without compromising the quality or integrity of the product. Structural steel prices can vary widely. And it can drastically vary from just one day to another. Major construction projects take much more time than just a few days to complete, so steel prices can throw your budget and your entire project into a tailspin. However, there are steps you can take to reduce your budget without putting your entire project at risk in this paper. 2 Introduction: A British inventor, Henry Bessemer, is generally credited with the invention of the first technique to mass produce steel in the mid-1850s. Steel is still produced using technology based on the Bessemer Process of blowing air through molten pig iron to oxidize the material and separate impurities. Steel is an alloy of iron and carbon containing less than 2% carbon and 1% manganese and small amounts of silicon, phosphorus, Sulphur and oxygen. Steel is the world's most important engineering and construction material. It is used in every aspect of our lives; in cars and

construction products, refrigerators and washing machines, cargo ships and surgical scalpels.

2.1 How is steel made: Steel is produced via two main routes: the blast furnace-basic oxygen furnace (BF-BOF) route and electric arc furnace (EAF) route. Variations and combinations of production routes also exist. The key difference between the routes is the type of raw materials they consume. For the BF-BOF route these are predominantly iron ore, coal, and recycled steel, while the EAF route produces steel using mainly recycled steel and electricity. Depending on the plant configuration and availability of recycled steel, other sources of metallic iron such as direct-reduced iron (DRI) or hot metal can also be used in the EAF route. About 75% of steel is produced using the BF-BOF route. First, iron ores are reduced to iron, also called hot metal or pig iron. Then the iron is converted to steel in the BOF. After casting and rolling, the steel is delivered as coil, plate, sections or bars. Steel made in an EAF uses electricity to melt recycled steel. Additives, such as alloys, are used to adjust to the desired chemical composition. Electrical energy can be supplemented with oxygen injected into the EAF. Downstream process stages, such as casting, reheating and rolling, are similar to those found in the BF-BOF route. About 25% of steel is produced via the EAF route. Another steelmaking technology, the open hearth furnace (OHF), makes up about 0.4% of global steel production. The OHF process is very energy intensive and is in decline owing to its environmental and economic disadvantages.

Most steel products remain in use for decades before they can be recycled. Therefore, there is not enough recycled steel to meet growing demand using the EAF steelmaking method alone. Demand is met through a combined use of the BF-BOF and EAF production methods. All of these production methods can use recycled steel scrap as an input. Most new steel contains recycled steel. 2.2 How many types of steel are there? Steel is not a single product. There are more than 3,500 different grades of steel with many different physical, chemical, and environmental properties. Approximately 75% of modern steels have been developed in the past 20 years. If the Eiffel Tower were to be rebuilt today, the engineers would only need one-third of the steel that was originally used. Modern cars are built with new steels that are stronger but up to 35% lighter than in the past. 2.2.1 Contemporary steel: Carbon steels Modern steels are made with varying combinations of alloy metals to fulfill many purposes. Carbon steel, composed simply of iron and carbon, accounts for 90% of steel production. Low alloy steel is alloyed with other elements, usually molybdenum, manganese, chromium, or nickel, in amounts of up to 10% by weight to improve the hardenability of thick sections. High strength low alloy steel has small additions (usually < 2% by weight) of other elements, typically 1.5% manganese, to provide additional strength for a modest price increase.[61] Recent Corporate Average Fuel Economy (CAFE) regulations have given rise to a new variety of steel known as Advanced High Strength Steel (AHSS). This material is both strong and ductile so that vehicle

structures can maintain their current safety levels while using less material. There are several commercially available grades of AHSS, such as dual-phase steel, which is heat treated to contain both a ferritic and martensitic microstructure to produce a formable, high strength steel. Transformation Induced Plasticity (TRIP) steel involves special alloying and heat treatments to stabilize amounts of austenite at room temperature in normally austenite-free low-alloy ferritic steels. By applying strain, the austenite undergoes a phase transition to martensite without the addition of heat. Twinning Induced Plasticity (TWIP) steel uses a specific type of strain to increase the effectiveness of work hardening on the alloy. Carbon Steels are often galvanized, through hot-dip or electroplating in zinc for protection against rust. Alloy steels Stainless steels contain a minimum of 11% chromium, often combined with nickel, to resist corrosion. Some stainless steels, such as the ferritic stainless steels are magnetic, while others, such as the austenitic, are nonmagnetic. Corrosion-resistant steels are abbreviated as CRES. Some more modern steels include tool steels, which are alloyed with large amounts of tungsten and cobalt or other elements to maximize solution hardening. This also allows the use of precipitation hardening and improves the alloy's temperature resistance. Tool steel is generally used in axes, drills, and other devices that need a sharp, long-lasting cutting edge. Other special-purpose alloys include weathering steels such as Cor-ten, which weather by acquiring a stable, rusted surface, and so can be used un-painted. Maraging steel is alloyed with nickel and other elements, but unlike most steel contains little carbon (0.01%). This creates a very strong but still malleable steel.

Eglin steel uses a combination of over a dozen different elements in varying amounts to create a relatively low-cost steel for use in bunker buster weapons. Hadfield steel (after Sir Robert Hadfield) or manganese steel contains 12–14% manganese which when abraded strain-hardens to form an incredibly hard skin which resists wearing. Examples include tank tracks, bulldozer blade edges and cutting blades on the jaws of life.

2.3 Standards Most of the more commonly used steel alloys are categorized into various grades by standards organizations. For example, the Society of Automotive Engineers has a series of grades defining many types of steel. The American Society for Testing and Materials has a separate set of standards, which define alloys such as A36 steel, the most commonly used structural steel in the United States. The JIS also define series of steel grades that are being used extensively in Japan as well as in third world countries.

2.4 How much steel is produced in a year? World crude steel production reached 1,689.4 million tons (Mt) for the year 2017. When it comes to steel production, one country is miles ahead of the pack: China. It accounted for a whopping 49% of the 1.7 billion metric tons of steel produced globally last year, according to industry group World steel. 2.5 What is smart manufacturing? Smart manufacturing does not just mean having a smart factory. It is a significant transformation in the way we source raw materials,

manufacture, and market our products through horizontal and vertical supply chain integration. It is a profoundly customer-focused concept. This change is not a one-step process as there are obvious challenges of trust and data security to overcome between diverse parties in the supply chain. There are a number of examples of early adopters within the steel industry; especially in vertical integration within business segments where building blocks of smart factories are being put together.

2.6 Is steel environmentally friendly and sustainable? Steel is very friendly to the environment. It is completely recyclable, possesses great durability, and, compared to other materials, requires relatively low amounts of energy to produce. Innovative lightweight steel construction (such as in automobile and rail vehicle construction) help to save energy and resources. The steel industry has made immense efforts to limit environmental pollution in the last decades. Producing one ton of steel today requires just 40% of the energy it did in 1960. Dust emissions have been reduced by even more.

2.7 Can steel be recycled? Steel's unique magnetic properties make it an easy material to recover from the waste stream to be recycled. The properties of steel remain unchanged no matter how many times the steel is recycled. The electric arc furnace (EAF) method of steel production can use exclusively recycled steel. Steel is the world's most recycled material. Steel is one of the world's most-recycled materials, with a recycling rate of over 60% globally in the United States alone, over 82,000,000

metric tons (81,000,000 long tons; 90,000,000 short tons) were recycled in the year 2008, for an overall recycling rate of 83%.

As more steel is produced than is scrapped, the amount of recycled raw materials is about 40% of the total of steel produced - in 2016, 1,628,000,000 tons (1.602×109 long tons; 1.795×109 short tons) of crude steel was produced globally, with 630,000,000 tonnes (620,000,000 long tons; 690,000,000 short tons) recycled.

2.8 Why does steel rust? Many elements and materials go through chemical reactions with other elements. When steel comes into contact with water and oxygen there is a chemical reaction and the steel begins to revert to its original form – iron oxide. In most modern steel applications this problem is easily overcome by coating. Many different coating materials can be applied to steel. Paint is used to coat cars and enamel is used on refrigerators and other domestic appliances. In other cases, elements such as nickel and chromium are added to make stainless steel, which can help prevent rust.

2.9 Uses Iron and steel are used widely in the construction of roads, railways, other infrastructure, appliances, and buildings. Most large modern structures, such as stadiums and skyscrapers, bridges, and airports, are supported by a steel skeleton. Even those with a concrete structure employ steel for reinforcing. In addition, it sees widespread use in major appliances and cars. Despite growth in usage of aluminium, it is

still the main material for car bodies. Steel is used in a variety of other construction materials, such as bolts, nails, and screws and other household products and cooking utensils. Other common applications include shipbuilding, pipelines, mining, offshore construction, aerospace, white goods (e.g. washing machines), heavy equipment such as bulldozers, office furniture, steel wool, tools, and armour in the form of personal vests or vehicle armour (better known as rolled homogeneous armour in this role).

3 Literature Review Before the introduction of the Bessemer process and other modern production techniques, steel was expensive and was only used where no cheaper alternative existed, particularly for the cutting edge of knives, razors, swords, and other items where a hard, sharp edge was needed. It was also used for springs, including those used in clocks and watches. With the advent of speedier and thriftier production methods, steel has become easier to obtain and much cheaper. It has replaced wrought iron for a multitude of purposes. However, the availability of plastics in the latter part of the 20th century allowed these materials to replace steel in some applications due to their lower fabrication cost and weight. Carbon fiber is replacing steel in some cost insensitive applications such as aircraft, sports equipment and high end automobiles.

Long steel  A steel bridge

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A steel pylon suspending overhead power lines As reinforcing bars and mesh in reinforced concrete Railroad tracks Structural steel in modern buildings and bridges Wires Input to reforging applications

Flat carbon steel  Major appliances  Magnetic cores  The inside and outside body of automobiles, trains, and ships. Weathering steel (COR-TEN)    

Intermodal containers Outdoor sculptures Architecture Highliner train cars

Stainless steel           

A stainless steel gravy boat Main article: Stainless steel Cutlery Rulers Surgical instruments Watches Guns Rail passenger vehicles Tablets Trash Cans Body piercing jewelry.

Low-background steel

Steel manufactured after World War II became contaminated with radionuclides by nuclear weapons testing. Low-background steel, steel manufactured prior to 1945, is used for certain radiationsensitive applications such as Geiger counters and radiation shielding.

2.11 Material properties Iron is commonly found in the Earth's crust in the form of an ore, usually an iron oxide, such as magnetite or hematite. Iron is extracted from iron ore by removing the oxygen through its combination with a preferred chemical partner such as carbon which is then lost to the atmosphere as carbon dioxide. This process, known as smelting, was first applied to metals with lower melting points, such as tin, which melts at about 250 °C (482 °F), and copper, which melts at about 1,100 °C (2,010 °F), and the combination, bronze, which has a melting point lower than 1,083 °C (1,981 °F). In comparison, cast iron melts at about 1,375 °C (2,507 °F). Small quantities of iron were smelted in ancient times, in the solid state, by heating the ore in a charcoal fire and then welding the clumps together with a hammer and in the process squeezing out the impurities. With care, the carbon content could be controlled by moving it around in the fire. Unlike copper and tin, liquid or solid iron dissolves carbon quite readily.

All of these temperatures could be reached with ancient methods used since the Bronze Age. Since the oxidation rate of iron increases rapidly beyond 800 °C (1,470 °F), it is important that smelting take place in a low-oxygen environment. Smelting, using carbon to reduce iron oxides, results in an alloy (pig iron) that retains too much carbon to be called steel. The excess carbon and other impurities are removed in a subsequent step.

Other materials are often added to the iron/carbon mixture to produce steel with desired properties. Nickel and manganese in steel add to its tensile strength and make the austenite form of the iron-carbon solution more stable, chromium increases hardness and melting temperature, and vanadium also increases hardness while making it less prone to metal fatigue. To inhibit corrosion, at least 11% chromium is added to steel so that a hard oxide forms on the metal surface; this is known as stainless steel. Tungsten slows the formation of cementite, keeping carbon in the iron matrix and allowing martensite to preferentially form at slower quench rates, resulting in high speed steel. On the other hand, sulfur, nitrogen, and phosphorus are considered contaminants that make steel more brittle and are removed from the steel melt during processing. The density of steel varies based on the alloying constituents but usually ranges between 7,750 and 8,050 kg/m3 (484 and 503 lb/cu ft.), or 7.75 and 8.05 g/cm3 (4.48 and 4.65 oz/cu in). Even in a narrow range of concentrations of mixtures of carbon and iron that make a steel, a number of different metallurgical structures, with very different properties can form. Understanding such properties is essential to making quality steel. At room temperature, the most stable form of pure iron is the body-centered cubic (BCC) structure called alpha iron or α-iron. It is a fairly soft metal that can dissolve only a small concentration of carbon, no more than 0.005% at 0 °C (32 °F) and 0.021 wt.% at 723 °C (1,333 °F). The inclusion of carbon in alpha iron is called ferrite. At 910 °C, pure iron transforms into a facecentered cubic (FCC) structure, called gamma iron or γ-iron. The inclusion of carbon in gamma iron is called austenite. The more open FCC structure of austenite can dissolve considerably more carbon, as much as 2.1% (38 times that of ferrite) carbon at 1,148 °C (2,098 °F), which reflects the upper carbon content of steel, beyond which is cast

iron. When carbon moves out of solution with iron, it forms a very hard, but brittle material called cementite (Fe3C).

When steels with exactly 0.8% carbon (known as a eutectoid steel), are cooled, the austenitic phase (FCC) of the mixture attempts to revert to the ferrite phase (BCC). The carbon no longer fits within the FCC austenite structure, resulting in an excess of carbon. One way for carbon to leave the austenite is for it to precipitate out of solution as cementite, leaving behind a surrounding phase of BCC iron called ferrite with a small percentage of carbon in solution. The two, ferrite and cementite, precipitate simultaneously producing a layered structure called pearlite, named for its resemblance to mother of pearl. In a hypereutectoid composition (greater than 0.8% carbon), the carbon will first precipitate out as large inclusions of cementite at the austenite grain boundaries until the percentage of carbon in the grains has decreased to the eutectoid composition (0.8% carbon), at which point the pearlite structure forms. For steels that have less than 0.8% carbon (hypoeutectoid), ferrite will first form within the grains until the remaining composition rises to 0.8% of carbon, at which point the pearlite structure will form. No large inclusions of cementite will form at the boundaries in hypoeuctoid steel. The above assumes that the cooling process is very slow, allowing enough time for the carbon to migrate. As the rate of cooling is increased the carbon will have less time to migrate to form carbide at the grain boundaries but will have increasingly large amounts of pearlite of a finer and finer structure within the grains; hence the carbide is more widely dispersed and acts to prevent slip of defects within those grains, resulting in hardening of the steel. At the very high cooling rates produced by quenching, the carbon has no time to migrate but is locked within the face-centered austenite and forms martensite. Martensite is a highly strained and

stressed, supersaturated form of carbon and iron and is exceedingly hard but brittle. Depending on the carbon content, the martensitic phase takes different forms. Below 0.2% carbon, it takes on a ferrite BCC crystal form, but at higher carbon content it takes a body-centered tetragonal (BCT) structure. There is no thermal activation energy for the transformation from austenite to martensite. [clarification needed] Moreover, there is no compositional change so the atoms generally retain their same neighbors. Martensite has a lower density (it expands during the cooling) than does austenite, so that the transformation between them results in a change of volume. In this case, expansion occurs. Internal stresses from this expansion generally take the form of compression on the crystals of martensite and tension on the remaining ferrite, with a fair amount of shear on both constituents. If quenching is done improperly, the internal stresses can cause a part to shatter as it cools. At the very least, they cause internal work hardening and other microscopic imperfections. It is common for quench cracks to form when steel is water quenched, although they may not always be visible.

Iron-carbon equilibrium phase diagram, showing the conditions necessary to form different phases

Heat treatment

There are many types of heat treating processes available to steel. The most common are annealing, quenching, and tempering. Heat treatment is effective on compositions above the eutectoid composition (hypereutectoid) of 0.8% carbon. Hypoeutectoid steel does not benefit from heat treatment. Annealing is the process of heating the steel to a sufficiently high temperature to relieve local internal stresses. It does not create a general softening of the product but only locally relieves strains and stresses locked up within the material. Annealing goes through three phases: recovery, recrystallization, and grain growth. The temperature required to anneal a particular steel depends on the type of annealing to be achieved and the alloying constituents.

Quenching involves heating the steel to create the austenite phase then quenching it in water or oil. This rapid cooling results in a hard but

brittle martensitic structure. The steel is then tempered, which is just a specialized type of annealing, to reduce brittleness. In this application the annealing (tempering) process transforms some of the martensite into cementite, or spheroidite and hence it reduces the internal stresses and defects. The result is a more ductile and fracture-resistant steel. 4 Understanding the Cost of Materials in the Steel Industry One of the costliest components of a new structure is often the steel foundation. Steel, LLC is one of the nation’s leading steel fabricators, and we would like to walk you through the materials process so you have a better understanding of how you can reduce costs.

In order to see where you can save on your next project, you need to understand the industry process. There are four distinct components of the structural steel supply chain:  Producers mills which manufacture structural steel products  Service Centers function as the warehouses and provide limited processing of structural steel before it goes to the fabricator;  Steel Fabricators physically prepare the steel, as well as distribution; and  Erectors those who assemble the steel into a frame on the construction site. These four groups of people have an enormous impact on the supply chain, obtaining the materials from your detailed construction documents and delivering those materials to your construction site. The way in which they handle these materials can have a direct impact on the cost of your project.

Sixty-five percent of all American steel is currently processed through the service centers. There are more than 1700 steel fabricators in the United States, and these fabricators can choose to order directly from the production mills, but this requires a longer waiting period. Service centers generally have two to three months of inventory in stock on the floor and can even assist with cutting and distribution, saving that effort from the fabricator. Ordering directly from the mills can be more cost effective, but only if you have the time to wait and the fabricators can assist with preparing the steel for assembly onsite. Of your steel package costs, 70% is in labor and distribution. The price of the material represents only 30% of your overall cost. The greatest cost-saving efforts should be focused on reducing assembly errors or changes, and remembering that least weight is not least cost. The price of the material is not nearly as impactful as the way that you are assembling the building. If you can make your builder’s job easier by simplifying connections and creating repetitions within your structure, you can save profoundly on labor costs. 5 Various methods to reduce the cost of steel fabrication

Engineers often specify steel when designing axles, bearings, shafts, gears, and a host of other components essential to the dependability and safety of both consumer and industrial products. But many of these engineer’s overlook specification practices that can lower the cost of steel parts. Here are eight tips that can lead to stronger, lighter, and less expensive parts and products:

1) Specify cold finishing. Cold finishing increases a metal’s tensile, yield, and torsional strength, as well as its hardness and wear resistance. It also improves the finish, dimensional accuracy, and machinability, all at a nominal cost increase. This means colddrawn carbon-steel bar can often be used instead of a more expensive alloy, or a low-cost alloy substituted for a more expensive grade. 2) Consider HSLA. High-strength, low-alloy steels (HSLA) cost less than full-alloy grades of equivalent yield strength and require no strengthening heat treatments in the mill or by users. This means they can be used to make lighter parts with no cost penalty. 3) Add surface carbon. The wear resistance of parts made from low-carbon-steel bar can be boosted by increasing the carbon content in the parts’ surface area, followed by heat treatment. Carbon is added through carburization, which involves furnacetreating parts at a high temperature in a carbon-rich atmosphere. Grades of steel most commonly carburized include AISI 1015, 1018, 1020, and 1117. 4) Use mill pretreatments. Heat treating bar steel at the mill is almost always less expensive than heat treating finished parts. This cost-saving alternative is feasible when subsequent manufacturing operations do not involve reheating the steel to above its transformation temperature. Another advantage of avoiding heat treatments after parts are formed or machined is the

elimination of potential problems such as cracking, distortion, and decarburization. 5) Specify special-quality steel bars. Using preheat-treated bars lets companies invest more in materials to simplify plant production processes and cut post-production costs. An example of this approach is the increasing use of special-quality bar steel which is made and conditioned to meet the exacting requirements of specific application or fabrication methods. Other examples include shaft-quality and rod-extrusion-quality bars. 6) Shape it hot and fast Automatic hot-forging equipment accepts mill-length steel bars at one end and turns out precision hotforged parts at the other. The bar is induction heated in seconds, goes through a three- or four-stage die series, and emerges as individual forged parts at rates as high as 180 parts/min. Another hot-forming process, extrusion, shapes full-length steel bars though dies to yield material and fabrication savings. Some processors take advantage of the heat content of the emerging extruded parts or shapes, putting them immediately through a heat-treatment cycle. 7) shape it cold. Parts can be chiplessly formed cold to shapes close to the final form to save on energy costs. Cold heading, extrusion, and draw-shaping could save up to 25% in material costs over screw-machine operations. And cold heading, for some arts, is faster than forging.

8) Be smart when buying. Purchasing and in-plant handling operations can also be adjusted to lower the cost of parts made from steel bar. For example, longer production runs and less handling become possible if the bar can be used in coils rather than cut bar form. Large coils also often improve the efficiency of annealing and leaning operations. Similarly ordering bar steel in large bundles reduces the per-pound handling fees. Other packaging practices should also be examined. “Extras” such as paper overwraps, skids, crating, color marking, and stamping of batch numbers or grade add to the cost of the steel. 6 The Main Objectives and Strategies of Manufacturing Manufacturers produce tons of goods every day, all of which impact consumers indirectly or directly. Similar to any industry, the manufacturing industry has specific objectives and corresponding strategies that are designed to improve a company's bottom line. These relate to quality, safety, vendor selection, problem identification and resolution, and efficiency and costs. 1) Quality When manufacturers do not produce a high-quality product, customers can begin to lose faith in the product and stop buying. Even if a company does an excellent job of sorting poor products from good ones, poor products mean a loss to the company, as the company cannot sell those items. For these reasons, one objective of manufacturing is reducing flaws and maintaining high product standards. Strategies might include weekly product sample reviews, while tactics might include physical tests of the product or visual inspections.

2) Safety Manufacturers often rely on heavy equipment, much of which is automated. This equipment -- although an asset in terms of boosting production numbers -- poses some risks to employees. For example, workers can be burned by heating elements or struck by joints that disconnect. Additionally, injuries can result from other sources, such as leaked liquids that can cause slips and falls. Manufacturers must, therefore, strive to reduce the potential for injury on the manufacturing floor. To do this, a strategy might be to enforce more regulations or offer incentives for being accident-free. The safety concern does not extend just to workers, however. Manufacturers also want to ensure that their products do not hurt customers or the general public in any way, particularly because injuries can prompt consumers to sue. 3) Vendors It is fairly rare for a manufacturer to have all the raw materials it needs to produce an item. For example, a cereal maker might not grow its own corn and, therefore, would have to find a supplier for it. Manufacturers have the objective of finding vendors that are both reliable and reasonable with prices. They also want to have strategies in place for what to do should vendors falter, as production should not stop simply because the company can't use a particular vendor. 4) Problems In manufacturing, everything from machinery wear to lower-thanexpected raw material quality can create major problems. Another manufacturing objective, therefore, should be to make some predictions about the problems that could arise so that those risks can be managed properly. A related objective is to identify the source of the potential problems. This isn't always easy, though, as problems could stem from more than one place in the manufacturing process. 5) Efficiency and Costs

Efficiency is interconnected with costs in manufacturing. In general, the more efficient a manufacturing company is, the lower its costs are. For example, if a manufacturer misses a production deadline, the company might face a contract penalty or lose a bonus. In the same way, if workers are taking too long to finish a project, the company may have to pay workers overtime or hire additional temporary staff to get back on schedule. Inefficiency can also waste other resources such as the raw materials that go into the product. It costs the company money to replace those resources. Another key objective of manufacturing, therefore, should be to keep the manufacturing process as efficient as possible. 7. Advantages of Steel  Steel is a kind of metal and Steel is resistant to rust.  Steel can be reuse and easy to recycle.  Steel can be made from iron, carbon, manganese, phosphorous, sulfur, silicon, nickel, chromium etc.,  Steel is also used in making household appliances.  Steel is an alloy of iron and Steel which is used in construction of roads, railway, buildings etc., because of its hardness and tensile strength.  Steel is strong, hard and flexible metal.  Stainless Steel is derived from Steel.  Skyscraper can be made of Steel.  Steel is used in a car frame.  A Ship are made of Steel.  Steel can be melted and Steel material is available easily.  Steel is also used in making stool and other office infrastructure.  Steel in used in construction of a buildings and infrastructure.  Steel is used in construction of bridge.

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Cabinets are made from Steel. Steel is used in automobile industry for making bikes, cars etc., Steel is used in hospitals. Steel is generally used in Civil Engineering. Steel is used in manufacturing cars: for example engine , body parts and doors of cars are made up of Steel. Steel is used in manufacturing of Electrical appliances such as washing machine, cooker, fridge etc., Steel is also used in make food packaging materials such as cans and other storage materials. Steel is also used in building products such as concrete rebars, metallic frames etc., Steel is used in making rail road tracks. Steel is also used in making train compartments. Steel is used in wheels and axles. Steel is also used in oils and gas wells. Steel can be used in manufacturing storage tanks. Steel in used in wind turbines. Steel is also used in manufacturing cranes. Steel can be used making transmission towers. Steel is used to make different types of machinery and tools. Protective instrument in companies are made up of Steel.

8. Disadvantages of Steel  The cost of production of Steel may be higher.  The resistance of Steel against fire is weaker compared to concrete.  Steel is heavy and expensive to transport.

9. Future Scope Future of the large span steel structures lies in the passion, setting up new goals and innovation in computerized designing procedures. The space frame companies will continue to develop steel structures with the extensive use of computers in both manufacturing and design phases. Computer aided manufacturing allows the cutting and drilling of elements with great precision, while computer aided design can help explore unprecedented complex configurations and geometries.