Performance of Surface Layers Applied by New Powder Wire in Highly Abrasive Wear

Аннотация

The influence of chromium (in high concentrations) as a reducing agent in the manufacture of Fe–C–Si–Mn–Cr–Ni–Mo powder wire is studied. Metal layers are applied to St3 steel plates under An-26S flux, with preliminary heating of the basic metal to 250–300°C. Powder wire (diameter 5 mm) manufactured on a laboratory machine is applied by means of an ASAW-1250 welding system, in the following conditions: current 420–520 A; voltage 28–32 V; welding rate 7.2–9.0 m/h. After surfacing, the metal is cooled to room temperature. In producing the powder wire, the filler consists of PZhV1 iron powder (State Standard GOST 9849–86); FS75 ferrosilicon powder (State Standard GOST 1415–93); FKh900A high-carbon ferrochrome powder (State Standard GOST 4757–91); FMn78(A) carbon ferromanganese (State Standard GOST 4755–91); PNK-1L5 nickel powder (State Standard GOST 9722–97); FMo60 ferromolybdenum powder (State Standard GOST 4759–91); FV50U0.6 ferrovanadium powder (State Standard GOST 27130–94); PK-1U cobalt powder (State Standard GOST 9721–79); and PVN tungsten powder (Technical Specifications TU 48-19-72–92). Within the chosen concentration ranges, carbon, manganese, chromium, molybdenum, nickel, and to some extent vanadium increase the hardness of the applied layer and also decrease the wear rate of the samples. The low viscosity of the matrix prevents the retention of tungsten carbide at the surface. Consequently, wear occurs not by uniform abrasion of the surface but by the extraction of high-strength carbon particles from the matrix. As a result, new cracks are formed in the matrix, which accelerates its wear. Multifactorial correlational analysis yields dependences of the hardness and wear resistance of the applied layer on the mass content of the elements in the Fe–C–Si–Mn–Cr–Ni–Mo powder wire. These dependences may be used to predict the hardness and wear resistance of the applied layer with change in its chemical composition.