Production and Application of Advanced High Nitrogen Steel

Abstract

Nitrogen was considered for long period to be in the same category as certain undesirable residual elements in steel, which are generally harmful for its properties. This was believed as high nitrogen contained steel is subject to ageing with deterioration of its plasticity with time. Recently, it was noticed that nitrogen has significant effect on mechanical properties, phase stability, corrosion behavior and oxidation resistance. Therefore, the technologies have developed to produce nitrogen and high nitrogen steels. The technologies for production of nitrogen steel including arc furnace , induction furnace, electro slag remelting, pressurised induction furnace, pressurised electroslag remelting, powder metallurgy and mechanical alloying - in addition to- the surface technologies such as gaseous solution nitriding, plasma furnaces, laser technology.Nitrogen became promising alloying element in steel, where nitrogen alloyed different steel grades such as Mn –steel, HSLA steel, duplex stainless steel, austenitic, ferritic and martensitic stainless steels which have applications in different fields. Steel Technology Department in Central Metallurgical R & D Institute (CMRDI) has significant contribution in development nitrogen steels using different techniques.