Ultra High Strength, High Fracture Toughness Low-Alloy Steel DMR-1700

A new NiSiCrCoMo low alloy steel, called DMR-1700, with a total alloy content of about 7 wt. %is developed. Strength-toughness combination of DMR-1700 steel is better than reported values for low alloy steels 300 M and D6 AC and falls in the upper bound range for 18Ni (250) maraging steel that has a total alloying content in excess of 30 wt. %. With base steel as filler, near 100 per cent weld efficiency can be achieved in welded and heat treated conditions. The reproducibility of attractive strength and fracture toughness properties has been established in tonnage scale melts at MIDHANI. The applications include Booster Motor Casings and armour. The steel is under production at MIDHANI, Hyderabad.