HARD-YET-TOUGH HIGH-VANADIUM HIGH-SPEED STEEL COMPOSITE COATING IN-SITU ALLOYED ON DUCTILE IRON BY ATMOSPHERIC PLASMA ARCCao, H., Dong, X. & Pei, Y. T. 2018 In : J. Comp. Meth. and Exp. Meas.. 6, 3, p. 540-550
Research output: Scientific - peer-review › Article
A graded high-vanadium alloy composite coating was synthesized from premixed powders (V, Cr, Ti, Mo, Nb) on ductile iron (DI) substrate via atmospheric plasma arc surface alloying process. The resulted cross-section microstructure is divided into three distinct zones: upper alloyed zone (AZ) rich with spherical primary carbides, middle melted zone (MZ) with fine white iron structure and lower heat affected zone (HAZ). Spherical or bulk-like primary carbides with diameter < 1 μmin the AZ are formed via in-situ reactions between alloy powders and graphite in DI. Microstructural characterizations indicate that the carbides are primarily MC-type (M=V, Ti, Nb) carbides combined with mixed hardphases such as M 2C, M7C3, M23C6, and martensite. Disperse distribution of spherical, submicron-sized metal carbides in an austenite/ledeburite matrix render the graded coating hard-yet-tough. The maximum microhardness of the upper alloyed zone is 950 HV0.2, which is five times that of the substrate. Significant plastic deformation with no cracking in the micro-indentations points to a high toughness. The graded high-vanadium alloy composite coating exhibits superior tribological performance in comparison to Mn13 steel and plasma transferred arc remelted DI.
|Journal||J. Comp. Meth. and Exp. Meas.|
|State||Published - 2018|