THE MECHANISM FOR INCREASING PITTING RESISTANCE OF STAINLESS-STEELS BY THE ADDITION OF MOLYBDENUM

Introducing 2.6 wt % Mo into stainless steel 0.03C17Cr14Ni sharply decelerates its pitting dissolution and raises its pitting resistance in neutral halide solutions much more effectively than adding MoO42- ions to the solution. Fitting corrosion can proceed at an equipotential surface as well, although it differs fundamentally in its kinetic characteristics from the active dissolution of steels in acidic halide solutions. Alloying with molybdenum can both accelerate and decelerate active dissolution.