Effect of Austenite Transformation on Abrasive Wear and Corrosion Resistance of Spheroidal Ni-Mn-Cu Cast Iron

Abstract

Within the presented work, the effect of austenite transformation on abrasive wear as well as on rate and nature of corrosive destruction of spheroidal Ni-Mn-Cu cast iron was determined. Cast iron contained: 3.1÷3.4 %C, 2.1÷2.3 %Si, 2.3÷3.3 %Mn, 2.3÷2.5 %Cu and 4.8÷9.3 %Ni. At a higher degree of austenite transformation in the alloys with nickel equivalent below 16.0%, abrasive wear resistance was significantly higher. Examinations of the corrosion resistance were carried out with the use of gravimetric and potentiodynamic method. It was shown that higher degree of austenite transformation results in significantly higher abrasive wear resistance and slightly higher corrosion rate, as determined by the gravimetric method. However, results of potentiodynamic examinations showed creation of a smaller number of deep pinholes, which is a favourable phenomenon from the viewpoint of corrosion resistance.

Effect of Annealing on Nature of Corrosion Damages of Medium-nickel Austenitic Cast Iron

“…Each time, polarisation was applied at 1 mV/s in the anodic direction. Corrosion resistance was determined on the grounds of cathodicanodic transition potential EK-A and stationary potential E', as well as of corrosion current density icorr and polarisation resistance Rp [8,[17][18][19][20].…”

“…When the EquNi value is larger than 16%, structure of raw castings is purely austenitic with its thermodynamic stability increasing along with the EquNi value [7][8][9]. Austenite stabilising action of nickel, manganese and copper consists mainly in inhibition of carbon diffusion in austenite, which results in reduced temperatures of eutectoidal, bainitic and martensitic transformations [2,8,[10][11][12][13].…”

“…Austenite stabilising action of nickel, manganese and copper consists mainly in inhibition of carbon diffusion in austenite, which results in reduced temperatures of eutectoidal, bainitic and martensitic transformations [2,8,[10][11][12][13]. Because of non-equilibrium solidification conditions, austenite can become supersaturated with carbon.…”

Effect of Heat Treatment of Austenitic Cast Iron (Ni-Resist) on Wear and Corrosion Resistance

“…Ni-Resist is cast iron with the main alloy nickel with the content of 12 until 34% [1]. Cast products with Ni alloy > 16% have austenitic microstructure with stability increasing with increasing nickel [2].…”

“…The austenitic structure that makes structural stability to occur during cooling is due to a decrease in the level of carbon diffusion in austenites [3]. Single phase alloy matrices are usually more corrosion resistant than multi-phase matrices [2]. Microstructure consisting of a mixture of austenite and martensite will increase the service life of components from cast iron [4].…”