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1 STEEL Use the arrow keys to easily navigate through the course. Back Next 1

2 STEEL 2

3 A BRIEF HISTORY OF STEEL The history of steel is closely connected to the development of human culture and civilization. The history of metal began with man, s attraction to its brightness and the realization that he could both shape and manufacture it into tools necessary for his survival. The first iron implements discovered in Egypt by archaeologists date from the year 3000 BC, but iron decoration was known even before then. The Greeks were utilizing techniques to strengthen iron weapons using heat treatment by the year 1000 BC. 3

4 A BRIEF HISTORY OF STEEL It was at the end of the Copper and Bronze ages, which lasted between 500 to 2,000 years, when the Iron Age began. Around 1200 BC. iron appeared in a more formal way in Asia or, giving rise to the first smeltings. Its use soon spread throughout the world, given its superiority to the materials used then, such as bronze and carved stone. Iron (except aluminum) is found in greater quantities than any other metal it can be extracted using relatively simple methods, and can be worked and transformed at will. The reason for the delay in the appearance of iron compared to bronze is because the high melting point of pure iron, made it practically impossible to obtain its minerals, and once treated they separated for the slag. 4

5 A BRIEF HISTORY OF STEEL Technological advances have helped man in his efforts to raise the temperature at which iron ore is subjected, ovens could now burn a mixture of ore and charcoal. This resulted in increased in production and made more economic sense. This has made large scale steel manufacturing possible. Today, steel is the most widely used material in modern societies. Steel is such an important material because it has highly resistant properties and, can be fabricated by machines into all manner of useful products. Furthermore, steel can be manipulated for specific purposes through the use of heat, mechanical workings, or creating alloys. 5

6 THE CLASSIFICATION OF METALS Metals and alloys used in industry and construction can be divided into two major categories: 1.- FERROUS MATERIALS 2.- NON-FERROUS METALS Ferrous comes from the word Ferrum which the Romans used for iron. Therefore, ferrous materials are those that contain iron as their main ingredient; that is to say, they possess the many qualities of iron and steel. Non-ferrous metals do not contain iron. These metals include aluminum, manganese, zinc, copper, lead and other metallic elements. Non-ferrous alloys are a combination of some of these non-ferrous metals and include the alloys brass and bronze. 6

7 THE NATURE OF STEEL Steel is basically an iron alloy that contains carbon (between 0.04% to 2.25%). Sometimes other alloying elements such as Cr (Chromium), Ni (Nickel) Bn (Manganese), Si (Silicon) or Vn (Vanadium) are added for various pre-determined reasons. 7

8 THE VARIOUS KINDS OF STEEL There are different types of steel, classified according to their alloy elements. CARBON STEELS More than 90% of all steels are carbon steels. These steels contain various amounts of carbon and less than 1.65% Manganese, 0.60% Silicon and 0.60% Copper. This is the type of steel used at DEACERO. CARBON STEELS ARE SUB-CLASSIFIED AS: A Low Carbon Steels: A carbon content of 0.25% B Medium Carbon Steels: A carbon content of >0.25% 0.42% C High Carbon Steels: A carbon content of > 0.42% 8

9 THE VARIOUS KINDS OF STEEL ALLOY STEEL These steels contain a certain proportion of vanadium, molybdenum and other elements, in addition to larger amounts of manganese, silicon, and copper than found in the normal carbon steels. These alloy steels can be subclassed as: STRUCTURAL Steels used for various parts of machines, such as gears, shafts and levers. TOOLING High-quality steels that are used in cutting and shaping tools for metals and non-metals. These metals are used to cut and build tools such as drills, reamers, milling cutters, dies and male threads. SPECIAL The special alloy steels or "stainless steel", are those with a chromium content usually more than 12%. These steels are extremely hard and possess high resistance to elevated temperatures and corrosion Hence they are used in steam turbines, gears, shafts and bearings. 9

10 CLASSIFICATION OF STEEL ASTM = AMERICAN SOCIETY FOR TESTING MATERIALS In practice, the classification systems of the American Iron and Steel Institute (AISI) and the Society of Automative Engineers (SAE) for carbon and alloy steel are regarded as worldwide standards. The identification system known as "The Steel Grade" expresses the type of steel. It is expressed in 4 digits, for example: 1008 FIRST DIGIT Denotes the type of steel: 1XXX Carbon Steels 4XXX Alloy Steels 10

11 CLASSIFICATION OF STEEL 10XX Carbon Steels ASTM = AMERICAN SOCIETY FOR TESTING MATERIALS SECOND DIGIT Indicates the presence of other alloying elements or the approximate level of the main alloying element. 11XX 12XX 15XX 41XX 51XX Desulfurized Carbon Steels containing 1% Manganese (easy cutting steels). Resulfurized and Rephosphorized Carbon Steels. Carbon Steels with high Manganese content (0.9 to 1.9%). Carbon Steel Alloyed with Chromium and Molybdenum. Carbon Steel Alloyed with Chromium. 11

12 CLASSIFICATION OF STEEL ASTM = AMERICAN SOCIETY FOR TESTING MATERIALS THIRD AND FOURTH DIGITS Indicates the approximate content of Carbon: 1020 Carbon Steels with a content of % Carbon Desulfurized Carbon Steels containing 1% Manganese and % Carbon Resulfurized and Rephosphorized Carbon Steels containing 1.15% of Carbon Carbon Steel Alloyed with Chromium and Molybdenum, with 40% Carbon content Carbon Steel Alloyed with Chromium, containing 60% Carbon 12

13 CLASSIFICATION OF STEEL ASTM = AMERICAN SOCIETY FOR TESTING MATERIALS Deacero manufactures carbon steel, from grade 10 to grade 15 The higher the grade the higher the carbon content and hardness of the steel. The lower the grade the lower the carbon content and hardness of the steel. Deacero foundries manufacture wire rod in many different grades in order to provide a wide variety of products to our diverse markets. 13

14 CHEMICAL SPECIFICATIONS AND MECHANICAL PROPERTIES SAE 1006 SAE 1008 SAE Grade C* Mn SI P S Cu Cr 0.22 Ni 0.22 Mo Sn B N RT % RA % E SPECIFICATIONS OF LOW CARBON WIRE 14

15 CHEMICAL SPECIFICATIONS AND MECHANICAL PROPERTIES 1010 SAE 1018 SAE E 1513 E 1011 R EW V Grade C* Mn SI P S Cu Cr Ni 0.07 Mo Sn B V N RT LF 42 % RA % E SPECIFICATIONS OF LOW CARBON WIRE 15

16 PRINCIPLE EFFECTS OF ALLOYING ELEMENTS OF STEEL The specific alloying elements and their quantities determine the type of alloy steel and its, properties. The main effects of some of the most common elements are: EFFECTS OF THE ELEMENTS ON THE PROPERTIES OF STEEL PROPERTIES OF STEEL C Mn V Mo Cr Ni Ti Zr B No Si Al S P Cu O N H Tensile Strength- Yield/Breaking Point Ductility Hardness Properties when Heat Formed Properties when Cold Formed Machining Properties 16

17 CLASSIFICATION OF ELEMENTS IN STEEL To summarize, the effects of the alloying elements are: Changes in the resistance and hardness of the steels Changes in impact resistance of the steels Changes in resistance to wear and tear Changes in corrosion resistance Change in the degree of machinability Higher resistance to high temperatures One of the main market advantages Deacero possesses is that it is able to manufacture the specific type of steel required for its products in its own kilns, manipulating and modifying the chemical composition of the steel, which results in mechanical properties tailored to each products. DEACERO manufactures material according to the needs of the client, it manufactures specialized wire according to predetermined chemical specifications and in compliance with required mechanical properties. 17

18 MECHANICAL PROPERTIES OF STEEL C Mn V Mo Cr Ni Ti Zr B Nb ALLOYING Carbon Manganese Vanadium Molybdenum Chromium Nickel Titanium Zirconium Boron Niobium DE-RUSTING Si Silicon AI Aluminum Ca* Calcium* RESIDUALES S ulfur P Phosphorus Cu Copper Zn* Zinc* O N H GASES Oxygen Nitrogen Hydrogen *DENOTES LIMITED SOLUBILITY 18

19 MECHANICAL PROPERTIES OF STEEL The mechanical properties of steel depend mainly on two factors: The Chemical Composition of the Steel: This includes the Grade of the Steel and Special Alloys ( Manganese, Vanadium, Silicon). The specific Heat Treatment of the Steel: Annealing (softened),tempering (hardened), Patenting (strengthened). 19

20 MECHANICAL PROPERTIES OF STEEL The most important mechanical properties of steel are: RESISTANCE TO STRAIN: The maximum strain that steel bar can undergo before it breaks. RESISTANCE TO YIELD OR CREEP STRESS: The maximum extent that the steel can be stretched so that when the load is withdrawn it returns to its original form without distortion. This is the design requirement for the calculation of reinforced concrete. BREAKING POINT ELONGATION: The elongation that a material experiences at the time of a break expressed as a percentage with respect to its original size. 20

21 OXIDATION (RUSTING) OF STEEL The biggest disadvantage of steel is that it rusts. Iron Oxide (FeO) is formed by the natural reaction of iron with existing oxygen in the air and in water, this is why when steel is housed outside in the elements, oxidation occurs at a more rapid rate. When steel is exposed to the elements for a long period of time, the level of oxidation increases in such a way that it penetrates the surface layer of the steel rod and corrosion begins to take place. 21

22 OXIDATION (RUSTING) OF STEEL The biggest disadvantage of steel is that it rusts. Oxidation eventually forms longitudinal fissures or cracks that much later become flakes that expel themselves from the surface of the steel bar decreasing its original diameter. For this reason, the bar loses load and bonding (adherence) capacity. Oxidation, which is purely superficial, must not be confused with corrosion, which is a very advanced stage of oxidation involving the formation of cracks in the steel. 22

23 OXIDATION (RUSTING) OF STEEL The biggest disadvantage of steel is that it rusts. The presence of rust on steel reinforcement is not detrimental to the resistance or the structural behavior of reinforced concrete. It has been proven that when the steel exhibits a layer of oxidation its adherence to concrete is actually dramatically increased, especially in smooth rods, and once casting is acheived the oxidation (rusting) process is interrupted and the reinforcement is protected by the concrete coating from further environmental attack. For this reason, American Official Standards for the manufacture of Welded Products (Welded Mesh, Electro-welded Precast products, and Reinforced/Corrugated products), does not consider the presence of rust as a reason for rejection of the material, as long as the nominal dimensions of the rods (diameter, corrugation, etc. ) are maintained. 23

24 OXIDATION (RUSTING) OF STEEL The American Society for Testing Materials (ASTM) certify for REBAR, RE MESH, WIRE REINFORCEMENT SHAPE FOR REINFORCEMENT OF CONCRETE are: ASTM Steel Wire and Welded Wire Reinforcement, Plain and Deformed, for Concrete. ASTM a Standard Specification for Deformed and Plain Carbon Steel Bars for Concrete Reinforcement. ASTM A a Standard Specification for Low-Alloy Steel Deformed and Plain Bars for Concrete Reinforcement. 24

25 STEEL Thanks!