Saudi Iron and Steel Company (Hadeed) has emerged as the region's largest integrated steel producer with a market base covering Saudi Arabia and 30 other countries globally.

Wholly-owned by Saudi Basic Industries Corporation (Sabic), Hadeed was established in 1979 in Jubail Industrial City as the first integrated iron and steel complex in the Kingdom. Since its commissioning in the early 1980s with a small capacity of 850,000 tonnes per year (tpy), the company's production capacity has grown to more than 3.5 million tpy.

The company's commitment to quality and customer service was rewarded in December 1994 with ISO 9002 certification.

Hadeed is a direct reduction (DR) electric arc furnace (EAF)-based plant and its present production constitutes both long and flat products. While concrete reinforcing bars, wire rod coils and light sections of various common shapes are in the long product category, the hot-rolled, cold-rolled and galvanised coils are part of its flat product mix.

Reinforcing bars

Reinforcing bars constitute a major portion of Hadeed's long-product mix. Although the rebars are made in a variety of chemical composition and mechanical properties to cater to a wide market requirements in this region, they are mostly made conforming to either ASTM A615 or BS 4449 specifications. High-strength grades (ASTM A615 Grade 60 and BS 4449 Grade 460A and B) of both the specifications are normally used. The product range though consists of sizes from 8 to 40 mm the majority requirement is for 10 to 20 mm bars.

"Concrete reinforcing bars are traditionally produced through the conventional hot rolling process. However, at Hadeed the advanced technology of the bar quenching process is used to produce these bars," a Hadeed spokesman says.

"While in the conventional process the properties are controlled through chemical adjustments, the properties of quenched steel rebars are due to their specific microstructure. In this process, instead of direct air cooling, the bars are water quenched for a short duration after hot rolling. This online heat treatment produces a specific composite microstructure with an outer protective rim of tempered martensite and a ductile inner core.

"Based on the requirements of the specifications and the specific knowledge of the rebar application, inplant specifications are prepared for the chemical composition and the targeted mechanical properties. These inplant specifications are generally kept much closer than the allowable ranges of the standard specifications to have a reproducible and consistent product quality. The product specifications then lead to the determination of the process parameters to be controlled at steel making, casting and rolling processes.

"The quality checks and control measure provided at every production stage ensure that the right product quality is dispatched to the customers. After-sales customer service is also available to resolve issues of customer dissatisfaction on any account.

The quality system and state-of-the-art production technologies for concrete reinforcing bar manufacturing at Hadeed has resulted in specific product characteristics," the spokesman says.

"High strength bars are used to provide the required load-bearing ability to the reinforced concrete structures. The quenched steel rebars are known to have higher yield strength than the conventional hot-rolled material. This strength is always accompanied by the comparable elongation and excellent bending characteristics.

"The tensile to yield strength ratio is also an important indicator of the material ductility and ability to prevent catastrophic failures. While the BS specification gives a minimum ratio of 1.08 for Grade 460 A, the average ratio for Hadeed rebars under this specification is always around 1.2.

"The consistent mechanical properties ensure that a consistent quality product is available to the project designers to have better confidence on their designs. The higher strength with good elongation may also give peace of mind to the project owner."

The spokesman says increased awareness of rebar corrosion in concrete has emphasised the necessity of corrosion prevention in the reinforced concrete structures to ensure considerable durability of these structures. Various measures are taken to combat rebar corrosion in concrete such as the use of concrete admixtures, application of protective coatings both on the concrete and rebar surface, application of cathodic protection systems and so on. However, under normal conditions the corrosion resistance of the rebar itself can become important.

"Various studies conducted by Sabic and Hadeed have revealed that the Hadeed quenched-steel rebars inherently have a higher corrosion resistance in concrete," the spokesman says. The result of a typical test indicated an increased resistance of concrete cracking for the samples made from Hadeed quenched steel rebars against the conventional hot rolled material, he claims.

Production facilities

Hadeed's long-product facilities include the direct reduction plant, which converts iron ore into sponge iron, and comprises three Midrex modules with a combined capacity in excess of 2 million tpy of sponge iron. It has iron ore handling facilities that include two ship unloaders and a 13.6 km. conveyor belt to carry the ore to an onsite storage yard.

The steel plant converts sponge iron and ferrous scrap into steel billets and has three electric arc furnaces, ladle transfer cars, two ladle furnaces and three six-strand continuous billet casting machines. The casting machines convert the liquid steel into billets with an annual capacity of approximately 2.8 tonnes.

The rolling mills convert 130 mm billets into finished products with a capacity of more than 2.8 million tpy. A rebar mill produces deformed and plain reinforcing bars in sizes 12 to 40 mm., having a capacity of 1.2 million tpy. A rod mill rolls billets into coils of wire rod and rebar in coils. It has a capacity of more than 700,000 tpy in a size range from 5.5 to 14 mm. A section and bar mill rolls reinforcing bars in sizes of 10 to 32 mm and light sections such as channels, equal angles, flats and squares with an annual capacity of more than 600,000 tonnes.

The major products in the long-product category are reinforcing bars (with applications in reinforced concrete and construction), wire rods (welded mesh, nails, screws, barbed wire and fence mesh industries) and light sections (structures, trailers and mobile homes).

The flat-product complex comprises a direct reduction plant and a steel plant.

The direct reduction plant with an annual capacity of more than 1 million tonnes of sponge iron is based on the HYL3 process with the latest technology available. Sponge (directly reduced) iron produced in this plant is the main feed material for the electric arc furnace.

The steel plant incorporates one 150-tonne ultra high power (UHP) electric arc furnace, a ladle furnace and continuous slab casting facilities with an annual capacity of more than 0.9 million tonnes.

Hadeed produces high-quality flat products to international specifications in accordance with customers' requirements. Closer dimensional tolerances, narrow range chemistry and special steel can be produced after mutual agreement.

Hadeed's flat steel finished products include the hot strip mill (850,000 tpy), hot coil slit and recoil line (260,000 tpy), hot coil cut-to-length (160,000 tpy), pickling line (480,000 tpy), cold rolling mill (496,000 tpy), batch annealing (150,000 tpy), temper mill (411,000 tpy), cold coil slit and recoil line (186,000 tpy) and hot dip galvanising line (200,000 tpy).

Hot rolled steel is produced at Hadeed's ultra-modern facilities and a comprehensive network of computers controls the entire manufacturing process to improve product quality to meet customers' requirements.

Hadeed offers a broad range of hot rolled products in the form of coils, slit coils and plates in pickled and unpickled condition. Hot rolled products satisfy the appropriate international standards, including those for structural and high-quality grades.

The hot rolled products include coils - (output 850,000 tpy, thickness 1.5-16 mm, width 900-1,650 mm, weight up to 30 tonnes) and plates (150,000 tpy, thickness 5-16 mm, width 860-1,600 mm, length 1.5 to 12 m and weight up to 10 tonnes).

The company's cold rolling mill comprises four high single reversing mills equipped with AGC roll swivelling device, a CVC roll, an axial shifting system and roll bending and multi-zone cooling systems. The mill is fully computerised to roll close dimensional tolerances both of low- and high-strength material.

Hadeed's cold rolled product is suitable for applications such as drawing, deep drawing and surface coating.

Hadeed produces 496,000 tpy of cold rolled coils, in thicknesses ranging from 0.3 to 3 mm, width of 850-1,650 mm and weight up to 30 tonnes.

Hadeed's modern hotdip continuous galvanising line is equipped with the latest technology including an electrolytic alkali degreasing line, vertical nonox-annealing, galvanising section, air knife wiper, cooling system, tension leveller, online electropassivation unit with electrostatic oiler and offline temper mill. The zinc coating has excellent adherence, formability, weldability, surface finish and corrosion resistance. The line can produce various coating weights on cold rolled, hot rolled drawing, commercial and structural quality strips to meet the wide range of customer demands.

Hadeed's output of galvanising coils is 200,000 tpy with gauges of 0.3 to 2 mm, widths 8501400 mm, coil weight up to 28 tonnes and coating weight: 80350/sq mm (both sides).