Study On The High Chromium Hardfacing Alloy Containing Mo

High chromium alloys surfaced on the ordinary carbon steel surface is widely used in abrasive wear, especially in the low stress abrasive wear of the workpiece's manufacturing and repair.At present, the study of high-carbon and high-chromium wear resistant surfacing-alloys mainly focused on the eutectic and hypereutectic hardfacing alloys at home and abroad. However, study on hypoeutectic hardfacing materials have been reported scarcely.In this paper, hypoeutectic hardfacing electrodes were developed. No cracks were produced in welding process, and electrodes were in good welding process. The content of Cr was added to the basic coating, and Mo element was transitioned to weld by basic coating recipe further. Optical microscope, SEM and EDS, XRD, spectral analysis, hardness testing,abrasive wear and other test methods were used to study the microstructure and properties of Hypoeutectic surfacing metal, the results showed that:After Cr element is added to the hardfacing alloy, the matrix microstructure of hardfacing alloy is mainly composed of martensite and austenite, carbide is composed of primary carbide(Fe, Cr) 7C3 and Cr23C6. When Cr content is low, the morphology of hardfacing alloy is the dendrite and columnar crystal. With the increase of Cr content, the morphology is columnar and equiaxed crystal. The amount of carbide increases with the increase of chromium content, so the hardness of surfacing alloy layer increased gradually.However, as the distribution of carbides from dispersion gradually transformed into network,the abrasion resistance decreased.After Mo element is added to the hardfacing alloy, microstructure of hardfacing alloy is mainly composed of martensite and austenite and carbide. Mainly types of carbide is(Fe,Cr)7C3 and Mo2 C and(Cr2.5Fe4.3Mo0.1)C3. When the content of Mo element increased from0% to 1.04%, the microstructure of the surfacing alloy is refined obviously. When Mo element content increased to 1.51%, the organization became thick. The wear resistance and hardness of surfacing alloy showed a decreasing trend after the first increase, but there has no simple correspondence between the hardness and wear resistance. The highest hardness is631 HV when the content of Mo is 1.04%. The abrasion resistance performance with the Mo content of 0.71% is the best, which is 2.2178 times compared with no Mo elements.