Changes in Abrasive Wear Resistance During Miller Test of Cr-Ni Cast Steel with Ti Carbides Formed in the Alloy Matrix

Austenitic chromium-nickel cast steel is used for the production of machine parts and components operating under corrosive conditions combined with abrasive wear. One of the most popular grades is the GX2CrNi18-9 grade, which is used in many industries, and mainly in the chemical, food and mining industries for tanks, feeders, screws and pumps. To improve the abrasion resistance of chromium-nickel cast steel, primary titanium carbides were produced in the metallurgical process by increasing the carbon content and adding titanium, which after alloy solidification yielded the test castings with the microstructure consisting of an austenitic matrix and primary carbides evenly distributed in this matrix. The measured hardness of the samples in both as-cast conditions and after solution heat treatment was from 300 to 330HV0.02 and was higher by about 40-70 units compared to the reference GX2CrNi18-9 cast steel, which had the hardness of 258HV0.02. The abrasive wear resistance of the tested chromium-nickel cast steel, measured in the Miller test, increased by at least 20% (with the content of 1.3 wt% Ti). Increasing the Ti content in the samples to 5.3 and 6.9 wt% reduced the wear 2.5 times compared to the common GX2CrNi18-9 cast steel.