Microstructure and wear properties of Fe–15Cr–2.5Ti–2C–xB wt.% hardfacing alloys

In this investigation an attempt was made to study the effect of boron on microstructure and wear properties of hardfacing alloys. A new type of Fe–Cr–Ti–C self-shielded metal cored wire with varying boron content were developed to fabricate the hardfacing alloys by self-shielded metal cored arc welding. Phase composition and microstructure of the as-prepared alloys were characterized by X-ray diffraction and scanning electron microscopy. Wear behavior was investigated using a ring-on-block tester. The results showed that the average diameter of M7(C, B)3 (M = Cr, Fe mainly) carbide increases from 9 to 20 μm and carbide volume fraction (CVF) increases from 14.10 to 36.00% with the boron increasing from 0 to 1.4 wt.% in the alloy. The hardness increases rapidly as boron content increases up to 0.99 wt.%, and then increases more slowly. Boron improves the wear resistance of the alloys. As the boron content exceeds 0.99 wt.%, the Fe–15Cr–2.5Ti–2C hardfacing alloy possesses excellent wear resistance.