Network Structure - A structure in which the crystals of one constituent are partially or entirely surrounded by envelopes of another constituent, an arrangement that gives a network appearance to a polished and etched specimen.
Nickel Steel - Alloy steel containing nickel as its principal alloying element.
Nitriding - Adding nitrogen to the solid iron-base alloys by heating at a temperature below the critical in contact with ammonia or some other nitrogenous material.
Nominal Dimension - O.D., I.D., or wall thickness of tubing specified by buyer, regardless of how the tolerances are expressed.
Normalizing - Heating to about 100°P (38°C) above the critical temperature and cooling to room temperature in still air. Provision is often made in normalizing for controlled cooling at a slower rate, but when the cooling is prolonged the term used is annealing.