SAIL Steel plates used in next gen stealth anti submarines corvette INS Kil

[RPK]

SAIL Steel plates used in next gen stealth anti submarines corvette INS Kiltan | India | SCRAP REGISTER NEWS


MUMBAI (Scrap Register): INS Kiltan, the Anti Submarine Warfare Corvette of the Indian Navy, designed under Project-28, was launched on March 26, 2013.

With nearly 90 percent indigenous content, the efforts made by Indian Navy and Defence Shipyards towards the national goal of indigenization and self-reliance got a major impetus with this latest ASW Corvette launch.

The ship's hull form is highly efficient with excellent sea-keeping and maneuverability characteristics with overall length of 109 meters. The ship can cut through the sea at a very high speed of 25 Knots.

Hull of the ship is built with warship grade high tensile indigenous steel. The DMR 249A steel has been developed and produced by Steel Authority of India Limited.

DMR 249A is a low carbon low alloyed steel and the specified gas contents of hydrogen is less than 2 parts per million (PPM) that gives the customized strength and toughness.

 

[SR-91]

Another breakthrough!!!

India is taking its foot off the brake pedal and about to step on the gas pedal.

DMR 249A

Low alloy steels are an attractive option for high performance structural applications due to cost and availability factors. A low carbon low alloyed steel, DMR 249A, was developed for strategic applications by Indian Navy at Steel Melting Shop II, Bokaro Steel Plant (SMS II, BSL). This paper enumerates the detail process variables modified for this development. DMR 249A grade was having the specified gas contents of hydrogen <2 ppm in final product for the avoidance of detrimental phenomenon like &#8220;Hair Line Cracks&#8221;. So the Hydrogen content of liquid steel was to be less than 3 ppm and this demand vacuum treatment of the steel. In absence of any Degassing unit at SMS II, BSL, making of DMR 249A steel was a challenging task. The hydrogen content of steel was controlled through restriction of hydrogen in input raw materials, control in degree of deoxidation during tapping, slag basicity at ladle furnace, argon rinsing regime and cooling of slabs i.e. control over diffusion of H2. The steel was produced with the existing infrastructure at Bokaro Steel Plant with various alloying elements and processed suitably to obtain the desired yield strength, toughness and gaseous content. The control was exercised at various stages of steel making and hot strip rolling to enable achievement of a higher degree of consistency in mechanical properties and microstructure. Quality fulfillment was a great challenge without vacuum degasser unit but Bokaro successfully made the steel with 100% customer satisfaction.

Seems like yesterday when SAIL started producing military grade steel.Making progress is always good to hear.