Effect of rare earth oxide nano-additives on micro-mechanical properties and erosion behavior of Fe-Cr-C-B hardfacing alloys

摘要

In this paper, the effect of rare earth oxide nano-additives on micro-mechanical properties and erosion behavior of Fe-Cr-C-B hardfacing alloys was studied. Optical microscope was used to observe microstructure of hardfacing alloys. X-ray diffractometer was used to analyze phases of hardfacing alloys. Vickers micro-hardness tester was used to measure micro-hardness of constitutional phases. Fracture toughness (K-IC) of primary carbide was calculated by indentation method. Erosion tests were carried out using JZB sand blaster. The experimental results showed that hardfacing alloys were hypereutectic, which were composed of M7C3, martensite and retained austenite. Nano-additives increased the hardness and the K-IC of primary carbide. The hardness of the primary carbide in the hardfacing alloy with 0.288 wt% nano-additives reached a maximum of 1716.54HV(0.2). The K-IC of the primary carbide in the hardfacing alloy with 0.432 wt% nano-additives was 9.27 MPa root m, which increased by 51.7% than that of the primary carbide in the hardfacing alloy without nano-additives. Erosion test results showed that nano-additives improved the erosion resistance of hardfacing alloys. The erosion rate of the hardfacing alloy with 0.432 wt% nano-additives decreased by 31.8% than that of the hardfacing alloy without nano-additives. (C) 2016 Elsevier B.V. All rights reserved.