EFFECT OF HEAT TREATMENT OF AUSTENITIC CAST IRON (NI-RESIST) ON WEAR AND CORROSION RESISTANCE

Abstract

Austenitic Cast Iron (Ni-Resist) is widely used for products with wear and corrosion resistance. The wear and corrosion resistance can be improved by heat treatment so that it has longer lifetime. The purpose of this research is to find out the appropriate heat treatment so that wear and corrosion resistance is optimal.Heat treatment is carried out normalizing, quenching and tempering (200 o C and 400 o C) on austenitic cast iron with the main alloy 17% Ni; 3,06% C; 2,77% Si and 2,13% Cr. The formation of austenite structures can improve wear and corrosion resistance. Tests carried out include wear resistance, corrosion resistance and micro analysis in as-cast and after heat treatment.The wear rate of the as cast is 1,34E-4 mm 3 /kg.m. Heat treatment increases wear resistance by 31% (normalizing), 63% (quenching), 88% (tempering 200 o C) and 75% (tempering 400 o C) compared to as cast. The corrosion rate of the as cast is 9,15E-5 mpy. Heat treatment decreases corrosion rate by 38% (normalizing), 52% (quenching), 29% (tempering 200 o C) and 14% (tempering 400 o C) compared to as cast. Increased wear and corrosion resistance occur due to changes in microstructure and graphite size.