Wear Behavior of Surface Treated X45MoCrV5-3-1 Tool Steel at Room and Elevated Temperatures

The aim of this study is to compare the wear behavior of X45MoCrV5-3-1 tool steel, used as die material in aluminum extrusion, after single treatment (CrN coating) and duplex treatment (nitriding and CrN coating). Gas nitriding and physical vapor deposition were used as processing techniques and wear tests were carried out at both room and elevated temperatures. A "ball-on-disc" type tribometer was used for room temperature tests, utilizing Al₂O₃ ball as counterpart. In order to simulate the wear conditions during extrusion, hot wear tests were carried out at 450°C using "block-on-cylinder" type tribometer against AA 6080 material. Worn surfaces were studied by microscopy to reveal the wear characteristics of treated steels. It was found that (i) duplex treated steel, having higher friction coefficient at room and elevated temperature, had higher wear resistance, (ii) at room temperature single treated steel exhibited higher volume loss than the duplex treated one, (iii) at elevated temperature duplex treated steel revealed a stable coating layer, whereas micro cracks were observed on the surface of the single treated steel.