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Quality that lasts for years & years !


	Product Range
	Surface Finish
	Tolerances
	Physical Properties
	Erichsen Values
	Manufacturing Process

» Manufaturing Process C.R Strips:

Process includes judicious selection of H.R. Coils that are sourced from the best steel producers in the country/imports, cold reduction to develop desired mechanical properties & crystallographic orientation subsequent to annealing & skin pass.

Product Testing & Quality Assurance
Quality in Surya Roshni is above everything else. The accent on quality commences with raw material selection and evaluation for various end products by thorough testing of metallurgical and physical properties. They are followed by strict quality checks at different stages of production processes to ensure that the finished CR Steel strips meet the required specifications.

The quality department is fully equipped to carry out variety of tests required.

1. Rockwell Hardness Tester and Vickers Hardness Tester .
2. Universal Tensile Testing machine.
3. Erichsen Cupping Tester.
4. Fully equipped quality laboratory has, amongst others, the following facilities;
* YS/TS automatic testing machine

Pickling In the semi continuous picking line the surface oxide layers of H.R.coils are removed by the action of warm Hydrochloric Acid which is subsequently rinsed by cold & hot water such that pickled.H.R.coils does not carry any acid & neither under or over pickled.
Cold Rolling Process comprises reducing thickness of H.R.Coils to desired thickness in several passes(According to a set pass schedule), Major parameters critical to quality, are thickness, shape & surface.
Annealing Steel after cold rolling become extremely hard and cannot be used because of loss of ductility. In order to restore ductility and formability, cold rolled coils are annealed in protective atmosphere to attain desired grain size and orientation.
Skin Passing Purpose of skin passing is four fold • Suppression of yields point phenomenon • Attainment of flatness in annealed product • Improvement of mechanical properties • Imparting bright or matt finish to material as desired by customer In addition to this semi processed electrical steels are given about 7-8% critical reduction so as to improve their magnetic properties after decarb annealing (process carried out by customer)
Slitting and Shearing After skin passing, the coils are slit to the required width by precision slitting machine. The coils are further sheared to the desired length by use of cut to length facility. The coils/sheets are thus supplied to the exact dimensional requirements for each end users to improve the yield of cold rolled steel coils/sheets.
Oiling and Packing The coils are provided with uniform coating of special rust preventive oil to guard against rusting, atmospheric corrosion and to allow storage for long duration. The oil coating can be easily removed by normal degreasing. Generally coils/sheets are securely packed in bituminized polythene lined hessian and tied with steel straps to avoid any damage during handling and storage. Special types can also be provided, such as metal envelope, sheets packed with a wooden skid etc. All finished products are tested for various quality parameters like hardness, tensile strength, elogation, Erichsen value. Only those products that meet the required specifications are dispatched to customers with proper packing in polythene and Hessian cloth wrapping/wooden pallets after applying rust preventive oil. The coil number and other details are marked clearly with stickers on the coil.