Manufacturing Process

Melting Scrap : The end product is as good as the raw material used. True to this statement, the melting scrap that is used is of highest quality including crc scrap from Faridabad and imported fabrication scrap. The scrap has minimal levels of adverse elements such as sulphur, phosphorus and silicon leading to better steel melting and eventually better end products.

Furnace : The melting shop is an induction furnace of Inductotherm, USA make. The batch capacity is 10mt.

Vaccum Degassing (VD) : The most critical part in steel melting shop is the refining of liquid steel which is done through a 10 mt capacity vd. The high pressure (1 milibar) generating capability of the VD through its 5 number of pumps and continous argon purging removes inherent gases such as nitrogen, oxygen and hydrogen from the steel.

Laddle Pouring : The conditioned material is laddle poured into appropriate mould sizes. Special attention is paid to the teeming time according to different ingot sizes.

Ingots : For providing higher reductions while rolling, a number of ingot sizes are cast.

Ingot Testing : After casting, each and every piece of ingot goes through a close physical inspection to discover any surface flaws. Then a sample of ingot is tested through a spectrometer to check the chemical composition of the material and is matched with the standards.

Ingot Conditioning : Succeeding the testing, ingots are conditioned so to achieve the desired form. All material is grinded using ingot grinders to remove any type of surface defects. Thereafter, the hot top and the lower section is cut from the ingot so as to improve the quality of the rolled product. After the completion of these processes, the ingots are sent for final examination and approved for further use. Proper heat wise records are maintained having the process sheet, the spectra report, the conditioning report and the final examination report for any future use.

Rolling Mill : Skyway has a six stand 14-inch rolling mill along with a heavy duty 22-inch roughing stand. The furnace of the rolling mill has a capacity of 70 mt. Special attention is paid to the furnace temperatures and soaking time (according to the grades) which are properly monitored and recorded. Automation of conveyors and applying plc controls in the rolling mill is currently underway. In addition a mechanical scale breaker is installed to provide better surface finish by removing excessive scale.

Cooling Pit : For slow cooling of critical grades after rolling, skyway has a cooling pit. The batch capacity of the cooling pit is 30 mt.

Physical Testing : After rolling, the material undergoes multi layered visual inspection which checks the following aspects:

Mechanical Testing : Checking the mechanical properties of rolled material is done through advanced machines. The following properties are tested:

These properties are duly recorded on respective test certificates (tcs) which are despatched along with the material.

Metallurgical Testing : First of all, spectrometer samples are drawn from the material to check the chemical composition of the material. Skyway has developed its own standards for reduction ratios, higher than the industry benchmarks. Even for size range 142mm-172mm round, reductions are kept at minimum 5:1 as opposed to general industry requirement of 4:1. Furthermore, the inclusion rating (ir), internal structure (is), grain size are studied through microscope. Full length ultra sonic testing is carried out to provide ultra ok finished products.

Identification : Paramount importance is given to the proper identification and marking of rolled products at skyway. 100% spark test is carried out, followed by identification through spectro gun. After this color coding is done as per standards followed by stickering and labelling on each bar.

Electric Annealing : Skyway has 3 number of top and 5 number of bases for annealing. The total installed capacity of annealing is 8,000mt per annum. All specialized types including spherodized annealing are carried out in highly controlled environment. The metal is heated above its recrystallization temperature and then systematically cooled. This process provides stringent control of decarb and hardness.

Shot Blasting : Breaking away from the conventional methods of acid pickling, skyway has installed a technologically Advanced shot blasting machine. The installed capacity of shot Blast material is 14,400 mt per annum.

Drawing : Cold drawn bright bars have much closer tolerances and better mechanical properties relative to as rolled material. Skyway has 2 number of draw benches. One is the medium ranged draw bench drawing materials from 16mm-56mm diameter. The other is the heavy duty draw bench, drawing material from 40mm-85mm diameter.

Centreless Grinding : for providing ground bars, a centreless grinder. Has been installed. In this process a layer of outer surface is removed and hence the material has a silvery bright, defect free surface. Also skyway provides the services of peeled material as per customer requirements.

MPI : A MPI machine is installed which is used for checking any surface seams or cracks. The material not conforming to mpi standards is directly rejected so as to provide our customers with the best possible quality.

Testing : along with all the testings done on as rolled material, 100% decarb control and hardness testing is done on these precision steels.

Identification : similar color coding, stickering and labelling is done on these processed steel.