Characteristics of WC-Co Layers Produced by the Electron Beam Cladding Method

摘要

In the previous report, electron beam cladding of WC-12%Co alloy powder by an electron beam welder was reported. WC-Co layers of over 800μm in thickness were formed on mild steel plates of 3mm in thickness. In this report, the characteristics of electron beam cladded layers were examined for abrasive wear and corrosion resistance. Test pieces after electron beam cladding were cut and molded in the resin of 25mm in diameter and 15mm in height. After polishing with an abrasive paper (#1500) and diamond paste of 0.3μm, they were examined by an optical microscope. They were also examined by X-ray diffraction and EPMA while Vickers hardness tests, abrasive wear tests and corrosion tests were carried out. Examination conditions were Cu-40kV-40mA for the X-ray diffraction, 20kV-0.05μm for EPMA and 300g load-15s for the Vickers hardness test. Abrasive wear tests were carried out for an abrasive surface area of 1.00cm~2 at 660g load in 30min-100 rpm. The replacement interval of abrasive paper #120 was 10min. For the corrosion test, test pieces were soaked in 50%H_2SO_4aq which was kept at 313K in a water bath after the cladded area of 1.00cm~2 was masked with epoxy resin, The weight loss was measured and corrosion rate was calculated.