Effect of Cr Element on Metallographic Microstructure and Properties of Fe-B Surfacing Alloy

Abstract

In order to improve the wear resistance of Fe-B surfacing alloy, plasma surfacing technology was used to clad Fe-B-Cr surfacing alloy layers with different chromium contents on the surface of Q235 steel material. The effect of Cr element content on the microstructure, hardness, and wear resistance of Fe-B-Cr surfacing alloy was studied by using metallographic analysis, scanning electron microscopy analysis, and X-ray diffraction analysis. Results showed that with the increase of Cr content, Cr was solidly soluble in Fe and Fe2B, and the surfacing alloy was composed of (Fe, Cr) and (Fe, Cr)2B. The increase of Cr content did not cause the formation of new phases in Fe-B surfacing alloy, and the alloy structure was composed of eutectic structures of Fe2B and Fe+Fe2B. Meanwhile, the addition of Cr element significantly improved the hardness and wear resistance of Fe-B surfacing alloy. The hardness of Cr-2 was considerably higher than that of Cr-0. With the continuous increase of Cr content, the hardness value of the surfacing alloy showed an upward trend, and the surface hardness of the Cr-10 surfacing layer was as high as 67 HRC. Moreover, the wear of the Cr-10 surfacing layer was minimized to 0.0275 g, and its relative wear resistance increased by 375% compared to Cr-0.

Keywords

• plasma surfacing technology|fe-b-cr surfacing alloy|structure|hardness