IWWSTEEL – Steel Manufacture in sri lanka

Our Products

The Manufacturing Process

A modern high technology semi-automatic manufacturing process rolls the bars of different sizes in specified diameter range and imparts high strength to the bar using the latest technique of the thermo mechanical treatment (QST). The raw material, steel billet/ingot is heated in a reheating furnace and rolled through a sequence of rolling stands equipped with roll sizes ranging from 360mm to 260mm which progressively reduce the billet to the final size and shape of the reinforcing bar.

The different sizes (diameter) of the bars are delivered from different roll stands at specifically controlled roll speeds. Almost all of these are finally controlled through DC drive & PLC control with well proven, sophisticated logic and sequence control, locally/remotely managed by experts. The sizes, ribs and identification/brand marking are achieved by inscribing the same on the rolls through a CNC machine.

The QST process takes over and the bar is subjected to heat treatment in three successive stages. The first stage of ‘Quenching , supplied and licensed by New Field India, under the world leading brand “Thermex” begins when the hot rolled bar leaves the final mill stands and is rapidly quenched by a special water spray system. This converts the surface layer of the bar to a hardened structure called ‘Martensite’ while the core remains “Austenitic”. The second stage of “Self Tempering” begins when the bar leaves the quenching box with a temperature of the core being higher than that of the surface. This allows heat to flow from the core to the surface, resulting in tempering of the surface, giving a structure called “Tempered Martensite” which is strong and tough. The Core is still “Austenitic” at this stage.

The bar travels through a set of auto controlled hydraulic twin channel which delivers the bar to a 30 mts long cooling bed for natural cooling by atmospheric air. The third stage of “Atmospheric cooling’ takes place on the cooling bed, where the Austenitic core is transformed to a ductile Ferrite-Pearlite core. Thus, the final structure consists of a combination of strong outer layer of tempered Marten site and ductile core of Ferrite-Pearlite. This is what gives Aditya QST bars its unique combination of strength and ductility. RS QST Bars offers a blend of strength and ductility, far in excess of the minimum limits of yield stress in the SLS 375:2009 standards. The typical values are as high as 500 N/mm2 though the standards specify 415 N /mm2 as normally used by architects. The typical value of ductility as measured by elongation is 18% minimum as against the standard value of 14.5% minimum. Undoubtedly, this ductility guarantees higher levels of safety.

We manufacture superior quality range of billets in variable sizes, dimensions as well as finishing. These long lasting ingots and billets can serve the most challenging, diverse industrial needs. Offered at best prices, these products we offer are known for their:

  • Corrosion resistive nature
  • Strength and durability

IWW Steel Industries offers its QST bars under the brand name RS. QST bars are produced through “Thermex Process”, German. We manufacture QST Bars from Size 8mm to 20mm in Grades RB 500. RS QST bars have high strength and good ductility, which make them especially suitable for high rise buildings, even in earthquake zones 4 and 5. RS QST bars exceed the requirements of SLS standards and other international quality standards.

Our mild steel bars are manufactured through standard processes and are used in architectural structures, frames of buildings and several other applications. With respect to the specific needs of our clients, we offer mild steel bars in different sizes, grades and thickness as per the applications they are meant for. We maintain dimensional tolerance and mechanical attributes for the bars we manufacture and serve. For prevention on rusting and wear in the mild steel bars we offer, we make use of the finest quality steel. Use of advanced, state-of-the-art technology has made our reputation as a leading manufacturer of mild steel bars.

Special Features

  • Bundling and automatic tying / strapping of the rounds ensure minimum damage during handling and transport.
  • Tension free rolling in the Light and Medium Merchant Mill ensures close dimensional tolerances.
  • You will also be benefited from delivery point of view. We can arrange the deliveries at a short notice of 12-48 hours and hence you can avoid maintaining huge stocks. Further, we will deliver the material at your site and this way you will be free from all sorts of transit risks