ABSTRACT
18Ni 8Co 1800 MPa Maraging steel is a low carbon iron-nickel martensitic alloy containing 18%Ni, 8%Co, 5%Mo, 0.4%Ti, 0.1%Al. They exhibit a unique combination of superior fracture toughness and excellent dimensional stability in the solution treated and aged condition. The applications of this marvels material are wide including use in rocket motor cases, cryogenic. However, this ultrahigh strength alloy is prone to corrosion attack. A good corrosion protection is possible by providing cadmium coating on finished maraging steel components by electrolytic means. Another cheaper way of providing corrosion protection to maraging steel components is by painting them with paint primer or “Japan Black”. They tend to get dried up as time passes giving a cracked mud appearance on the surfaces of the coated parts causing corrosion of the underlying maraging steel from the entrapped moisture. This paper discusses another effective way of preventing corrosion in Maraging steel by forming a passive oxide layer on the surface of the steel. This is envisaged to be achieved by exposing the finish machined maraging steel components to a stream of superheated steam, resulting formation of corrosion inhibition layer.
