Corrosion-abrasion wear resistance of 28%Cr white cast iron containing boron

Abstract

The influence of boron additions (0–0.6 wt.%) on the corrosion resistance and corrosion—abrasion resistance of 28%Cr white cast iron has been studied. Experimental results show that in static corrosion tests the corrosion rate (pH = 1) increases with increasing boron content, but its corrosion resistance is much better than that of 15%Cr cast iron. The 28%Cr iron is passivated when pH > 3. In the corrosion-abrasion wear process there exists a certain correlation between corrosion-abrasion wear resistance and corrosion resistance. When pH = 1, boron increases the weight loss during corrosive-abrasive wear, but boron abruptly decreases the weight loss when the pH reaches 3. It is considered that corrosion predominates when pH = 1 and abrasive wear predominates when pH > 3 in the corrosion—abrasion wear process. In the latter case, being able to increase the hardness of both carbide and matrix, boron can effectively increase the corrosion—abrasion wear resistance of the iron.