Hardness and Wear Resistance of TiC-Fe-Cr Locally Reinforcement Produced in Cast Steel

Abstract

In order to increase wear resistance cast steel casting the TiC-Fe-Cr type composite zones were fabricated. These zones were obtained by means of in situ synthesis of substrates of the reaction TiC with a moderator of a chemical composition of white cast iron with nickel of the Ni-Hard type 4. The synthesis was carried out directly in the mould cavity. The moderator was applied to control the reactive infiltration occurring during the TiC synthesis. The microstructure of composite zones was investigated by electron scanning microscopy, using the backscattered electron mode. The structure of composite zones was verified by the X-ray diffraction method. The hardness of composite zones, cast steel base alloy and the reference samples such as white chromium cast iron with 14 % Cr and 20 % Cr, manganese cast steel 18 % Mn was measured by Vickers test. The wear resistance of the composite zone and the reference samples examined by ballon-disc wear test. Dimensionally stable composite zones were obtained containing submicron sizes TiC particles uniformly distributed in the matrix. The macro and microstructure of the composite zone ensured three times hardness increase in comparison to the cast steel base alloy and one and a half times increase in comparison to the white chromium cast iron 20 % Cr. Finally ball-on-disc wear rate of the composite zone was five times lower than chromium white cast iron containing 20 % Cr.

Technology of Alloy Layers on Surface of Castings

“…Wear resistance of the studied layered casting is larger than the wear resistance of the compared cast irons and steel. Similar results related to the increase in the abrasive wear resistance along with the increase in hardness were also obtained in studies described in other papers [7][8][9] concerning the reinforced surface layers on grey cast iron castings.…”

“…liquid-liquid, 3,4 solid-solid 5 and liquid-solid. [6][7][8][9][10][11][12][13][14][15] An example of the former is a technology in which two independent gating systems are made, which guarantee a two-stage filling of the sand mould cavity. According to this manufacturing method, the bimetallic elements of hammer 3 or ball 4 mills are cast in material configurations of an abrasive wear resistant chromium cast iron working layer with a ductile low-carbon cast steel base, whereas application of the second technology allows to obtain relatively small elements in steel-cast iron configuration.…”

“…5 Moreover, the basis of the technology of layered castings made using the liquid-solid system is a so-called method of mould cavity preparation. In this manufacturing method, the element that enriches the surface of the casting is placed in a mould in the form of a granular [6][7][8][9] or monolithic [10][11][12][13][14][15] insert, directly before molten metal is poured. According to this manufacturing method, the bimetallic elements of runners 6,7 or lining plates 13,14 are cast in material configurations, connecting an abrasion and corrosion resistant high-alloy stainless steel or Cr base alloy working layer with a grey cast iron or carbon cast steel base.…”

Optimizing the Gating System for Steel Castings

“…Most heavy casting was made from cast steel, including the heaviest castings that were ever cast for hydraulic presses, forging hammer frames, or parts for offshore energy facilities for example the heavy hydro turbine blades [4][5][6][7][8]. This was due to the superior properties of many cast steel grades and the possibility of being able to tailor the properties to specific conditions with heat treatment or surface engineering [9][10][11], bi-metallic casting production, including welding techniques, etc. [12][13][14].…”

Wear Resistance of TiC Reinforced Cast Steel Matrix Composite

“…In general, they are composed of hard ceramic particles in ductile iron alloys matrix. The main advantage of this materials is hardness in the range of 700 -1600HV [3][4][5][6].…”