Speciality Steels for Naval Applications
To cater to the needs of the Indian Navy, DMRL successfully developed the technology for indigenous production of AB class of steels using the infrastructure existing in the country. Indigenous versions of AB class of steels, namely ABA and AB2, are designated as DMR‐249A and DMR‐ 249B, respectively.
| Steel | YS (MPa) | UTS (MPa) | El (%) | CVN Impact Toughness (J) |
|---|---|---|---|---|
| DMR‐249A | > 390 | 510 ‐ 690 | > 20 | > 78 at ‐60 °C |
| DMR‐249B | 585 ‐ 690 | > 655 | > 18 | > 78 at ‐40 °C |
- Continuous casting route has been successfully established to make the steel cost effective
- DMR‐249A steel: Controlled rolling helps meet specifications in asrolled condition itself (for plate thickness < 20 mm) obviating the need for heat treatment
- Bulb bars have asymmetric x‐sections and are used as stiffeners in ship building
Cost Comparison
Imported Plates : About 4 to 8 times the indigenized plates
Imported bulb bars : About 2 times the indigenized bulb bars
INS Vikrant
Launched in August 2013 18,000 tons of indigenous steel used Indian Navy has nominated the use of DMR‐249 steels for all new construction of IN warships as well as future repairs Estimated savings till date Rs. 2000 Crores
