In-Depth Microstructural Analysis of Galling Deformation in Stainless Steels

Microstructure formation in the powder HIPed hardfacing alloy Tristelle 5183 (Fe-21%Cr-10%Ni-7.5%Nb-5%Si-2%C in wt%)

“…The fine scale carbide precipitates are also homogeneously distributed within the austenitic matrix, and this reduces the effective matrix mean free path. This reportedly minimises the matrix-to-matrix contacts during sliding and so potentially improves adhesive wear resistance compared to cast or PTA weld overlays [39,41] 4. M 7 C 3 carbide formation is largely suppressed in the gas atomised powder and precipitate out during HIPing with a basic orthorhombic crystal structure (Pmcn space group) that is largely flawed with {110} planar crystallographic defects.…”

“…It is therefore suggested that whilst the CALPHAD approach requires further improvement, it can still provide significant insight into phase evolution and phase stability if carefully interpreted and rationalised against experimental observations. The HIPed microstructure is probably important from a tribological perspective as the carbide size, fraction and spatial distribution are factors which govern a materials adhesive wear behaviour [16,[39][40][41]. In comparison with the alloy in its other forms, such as cast ( [19]) or Plasma Transferred Arc (PTA) welded ( [12]), the powder HIPed alloy has both a very fine matrix grain size and equiaxed carbide grain structure.…”