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Steel products
- 1. What is steel? Steel is the general name given to a large family of alloys of iron with carbon and other elements. Steel is such a versatile material because we can adjust its composition and internal structure to tailor its properties for certain application.
- 2. Types of Steel Plain Carbon Steels - Low Carbon/Mild Steel - up to 0.25% - Medium Carbon Steel 0.25% to 0.45% - High Carbon Steel 0.45% to 1.50% Alloy Steels - High Strength Low Alloy - Stainless
- 3. Steel Grades Varying with carbon content High Carbon Steel (0.45 - 1.5 %) Medium Carbon Steel (0.25 - 0.45 %) Mild Steel (up to 0.25 %)
- 4. Product Category Long Products - Bars - Wire Rods - Sections Flat Products - Plates - Sheets
- 5. PERWAJA STEEL SDN BHD Process & Products Flow DRI
- 6. PERWAJA STEEL SDN BHD Direct Reduced Iron (DRI) Chemical Composition Total iron 90.0% min. Metallic iron 83.0% min. Metallization 92.0% min. CaO / SiO2 0.70% min. C 2.0 – 3.0% (Typical 2.4%) P 0.10% max. S 0.01% max. Gangue 6.0 % max. Physical Properties DRI size 6.3 mm ø min Size distribution + 15.9 mm 10% max. - 6.3 mm 3% max. Bulk density (kg/m3) 1.65 min. Compressive strength average 90 min. (kg/piece)
- 7. PERWAJA STEEL SDN BHD SMS Products Billet 120 x 120 150 x 150 200 x 200 Bloom 250 x 200 250 x 300 250 x 350 Beam Blank 120 390 470 x 390 x 120 All measurements are in mm 470
- 8. Billets Chemistry The chemical composition of the billets depends on the end use as given in the table below. High-rise building application Vs. different drawn wire size Electrodes Welding Electrode Spec. & steel grade list CO2 Wire (1) Mn (max) depends on CE <=0.51 = C + (Mn/6 + Cr + Mo + V) / 5 + (Ni + Cu)/15
- 9. Steel Grade Database System Main Menu Coding System Specification Summary Billet Steel Grade Coding System Bloom Steel Grade Coding System Customer List
- 10. Reinforcement Bars Reinforcement Size Bars (mm ø) High Tensile 10 ~ 40 Deformed Bars Mild Steel 10 ~ 40 Round Bars Standard length is 12 m The steel bars produced by Perwaja conform to MS 146 2000 for : Grade 250 Mild Steel Round Bar Grade 460 High Tensile Deformed Bar Grade 500 High Tensile Deformed Bar Perwaja Steel also produces bars meeting the BS 4449 1988 specifications .
- 11. Wire Rods Wire Rods Size (mm ø) Round 5.5 ~ 14.0 Deformed 10.0 & 12.0 Grade Round MS 144:1987, JIS G3505:1980, SWRM 10K – 12K AISI / SAE 1010K – 1012K Deformed MS 146: 2000 Weight and Packing In standard weight coils of about 1000 kg each (max) securely strapped
- 12. Wire Rod Applications Nails Wire Mesh Welding Electrodes CO2 Wire
- 13. RSS Applications Wire Welding Electrode PVC Coated Wire Wire Rod Paper Clip Armoured Cables Fine Wire Wire Netting
- 14. Sections Sections Size (mm) H beam 150 X 150 ~ 600 X 300 I beam 200 X 100 ~ 600 X 190 C channel 150 X 75 ~ 380 X 100 Angles 125 X 125 ~ 200 X 200 Sections List
- 15. Section Applications Transmission Tower Maju Perdana Tower Off-shore Structure
- 16. Product Certification MS 146:2000 Bars Perwaja Steel produces direct reduced iron, steel billets, blooms, beam blanks, deformed bars, wire rods, drawn wire & nails, and sections. INSIST ON QUALITY - PERWAJA STEEL MS 144:1987 Wire Rods http://www.perwaja.com.my/ JIS G 3101:1987 H Beam & C Channel
- 17. Thank you
Notas del editor
- There are thousands of different kinds of steel. Steel is the general name given to a large family of alloys of iron with carbon and a variety of different elements. Even small differences in the composition of the steel can have a dramatic effect on its properties. The properties of the steel can also be modified by different mechanical and heat treatments. Steel is such a versatile material because we can adjust its composition and internal structure to tailor its properties. So we can produce a steel for paperclips, thin strips of steel for razor blades, a steel for bridges and large beams for columns and skyscrapers. The volume of steel consumed has been the barometer for measuring development and economic progress. Considering a steel consumption of 300 kg per man per year to be a fair level of economic development for certain country/nation. Whether it is construction or industrial goods, steel is the basic raw material. Lighter metals and stronger alloys have been developed, plastics and synthetics have replaced steel in many areas. Hence, another major feature in the steel industry is the continuous improvement of steel grades. Half of today’s steel grades were not available ten years ago. Just take an example of the most commonly used steel – rods or bars, used as reinforcement material with cement concrete. It is used to be plain bars even in the sixties, then came the ribbed bars, followed by the twisted deformed bars and now it is thermo-mechanically treated bars. Each development has added to the strength of construction. Older varieties of steel have been improved upon and newer grades introduced. The process continues.
- Steels are described as mild, medium or high-carbon steels according to the percentages of carbon, although is never greater than about 1.5 %. Adding metals such as nickel, chromium, etc to iron produces a wide range of alloy steels, for instance stainless steel.
- The properties of steel are closely/strongly related to its chemical composition. For example, there is a big difference in hardness between the steel in a drinks can and the steel that is used to make a pair of scissors. The metal in the scissor contains nearly twenty times as much carbon and is many times harder. Changing in carbon content changes the properties of the steel and the way that it is used. The steel is more malleable as the carbon decreases. Generally, carbon is the most important commercial steel alloy. Increasing carbon content increases hardness and strength and improves hardenability. But carbon also increases brittleness and reduces weldability because of its tendency to form martensite. This means carbon content can be both a blessing and a curse when it comes to commercial steel.
- Rolling process deforms the cast product into required shape. There are three groups of rolled long products namely bars, rods and sections. The hot-rolled flat products can have the form of plates, sheets or strips. Hot-rolled products are often subjected to further processing such as cold-rolling (for good surface finish), machining, etc. in order to achieve a variety of steel products. At further downstream, the hot-rolled plates can be processed to form longitudinal welded pipes of large diameter. Other principal hot rolling product groups that can be distinguished are seamless tube rolling, specialty products such as wheels, rings, etc.
- The iron ore is heated up to about 900 °C, and as it descends down the shaft furnace, they are reduced. The reducing gas (with high concentration of H2 & CO) flows upwards and in countercurrent with the descending flow of iron ores by gravity. The H2 & CO reacts with the oxygen in the iron ore to become water vapor (H2O) and CO2 respectively, at the reduction zone. The reduced iron ore is therefore rich in metallic iron (M.Fe). At the cooling zone, the DRI is cooled down to 50°C by a mixture of natural gas and reducing gas and it is during this process where most of the carbon in the DRI is formed. The cooled DRI is then screened before sending to the meltshop for use. At the meltshop, scrap is charged into the Electric Arc Furnace. The scrap is melted to form a molten pool. DRI is then top fed into the molten steel and during this period, the temperature at around 1580°C. After DRI feeding is completed, molten steel sample and temperature are taken for analysis. Molten steel temperature is then raised to the required tapping temperature, and then tapped out from the Electric Arc Furnace into a ladle by forward tilting. After skimming, the ladle is placed on a ladle transfer car. The transfer car is then moved to a Ladle Furnace Station. At the Ladle Furnace Station, molten steel temperature and chemical composition are homogenized by bubbling. Final adjustment of chemical compositions and temperature are made before sending to the Continuous Casting Machine. The ladle is placed on a ladle turret. The ladle turret is then swung into casting position. The ladle sliding nozzle is then opened to allow molten steel into the tundish. Molten steel in the tundish is maintained at a certain level to regulate the required casting speed. The process of casting takes place in the copper mould which is indirectly cooled with water. Billet is cooled further directly by secondary spray cooling system. The billet strand is later cut by an oxygen torch to the required length as specified by the customer. From here, billets are transported by land to the Gurun Plant. The billets are then charged into the reheating furnace, after the checking for internal and surface defects. During the heating process, the surface of the billets tends to oxidize and forms scales. These are removed before the billets are used for the next process using descaler. The billets are then charged into a series of roll stands, where the billets will undergo a shaping process to reduce the diameter of the billets to the desired size. The specified final diameter determines the size and amount of roll stands the material has to go through.
- Welding Electrode Grade: PS2007A – for Electrode Product Sdn. Bhd. (subsidiary of PNB). PS2007B – for MOX Bhd. It is noted with the small deviation on the chemical composition to suit with customer requirement w.r.t. different electrode fluxes/rod strength. Why low Si? - related to the influence of Si content on coating weight for good galvanizing and drawability. - & vs. influence to electrode fluxing.
- Database records: Standard Steel Grade Specification for Billets – 115 records. Customer List – 38 records (exported to Vietnam, Taiwan, Philippines, Indonesia, Australia,etc. and recently to Iran (through Cargill). Standard Steel Grade Specification for Bloom and Beam Blank – 29 records.
- Bar rolling is conducted in several passes. After each pass the cross-section of a stock is reduced and the shape of a stock more and more approaches to the shape of a final product. There are different types of hot-rolled bars commonly used such as round bars or deformed bars (produced at Gurun Plant), square bar, hexagon bar, etc.
- Wire rod can be used as a starting material for production of a variety of products, such as wire, wire ropes, springs, bolts, nuts, nails, screws, bearings, tire cords, music wire, core wire of covered electrodes, etc.