Development Of Abrasion Resistance High Chromium Cast Iron Self-shielded Flux Cored Wire

Using surfacing technology to repair be-worn parts, or manufacture wear resistantcomposite, can dramatically improve part’s service life. Due to it’s higher hardness andbetter toughness, high-chromium cast iron can effectively resist abrasive wear, becomeone of the most widely used hardfacing materials.High chromium cast iron self-shielded flux cored wires contained Mo,W, V and Nbwere developed in this paper. Weight percentage of the powder compositions are: highcarbon ferrochrome47-79%, graphite2-4%, high carbon ferromanganese4-6%,ferrosilicon4-7%, ferroboron0-5%, ferrotungsten0-3%, ferromolybdenum3-6%,ferrovanadium0-6%, ferrocolumbium0-6%.Deposited metal samples were made, and the microstructure, hardness, phase,abrasive wear properties were analysised and tested. The influence of welding voltage,welding speed, different surfacing orders and anti-deformation measures to the weldingdeformation were investagted as well.Experiments show that:(1) The microstructure is primary carbides (Cr，Fe)7C3+eutectic matrix (eutectic(Cr，Fe)7C3and retained austenite or martensite)+carbide of V, Nb, B etc.(2) The wear resistance of surfacing layer was depend on its microstructure, forexample, the quantity of retained austenite, the size of primary carbides, the distribution ofhard phase.(3) Different anti-deformation measures have the biggest impact on the weldingdeformation. Using composite method can control the welding deformation effectively,rigid fixing second, and water cooling method nearly cann’t improve the anti-deformationeffect.(4) Welding voltage and welding speed also have some influence to the weldingdeformation. Along with welding voltage increased, the deformation decreased. Alongwith welding speed increased, the deformation increased at first, then keep steady.(5) Different surfacing orders nearly cann’t affect the deformation. But symmetricalheat input position have beneficial effect to decrease deformation.