Dry sliding wear of as-cast and thermomechanically processed low chromium white cast iron
This investigation attempts to improve the wear resistance of low chromium white cast iron (LCCI) by thermomechanical treatment. The thermomechanical treatment of the brittle LCCI with crack-free was successfully carried out by bonding it with a ductile low carbon steel firstly. Afterwards the dry sliding wear behavior of as-cast (LCCI-A) and thermomechanically processed (LCCI-B) samples was studied using a pin-on-disc apparatus under different test conditions. The microstructural examination shows that the refined supercooled austenite and plenty of secondary carbides in LCCI-B replaced the original microstructure of martensite and retained austenite with network carbide in LCCI-A. This significant evolution is beneficial to form and stabilise the oxide layer on the substrate, which makes the oxidational wear rather than abrasive wear or delamination dominating the wear process so that the improvement of the wear resistance of LCCI was achieved by hot working.