Development of Low Cost Corrosion Resistant Fe-Cr-Mn-Mo White Cast Irons

Cast irons are basically binary alloys of iron and carbon having carbon exceeding its maximum solid solubility in austenite but less than the carbon content of iron carbide. However, like steels, cast irons have varying quantities of silicon, manganese, phosphorus and sulphur. Silicon plays an important role in controlling the properties of cast irons and for this reason, the term cast iron is usually applied to a series of iron, carbon and silicon alloys. Special purpose cast irons include white and alloy cast irons which are mainly used for applications demanding enhanced abrasion, corrosion or heat resistance. In present study, corrosion resistant cast irons are of our interest.

Phase Relationships in the Y–Fe–V Ternary System at 773 K

The isothermal section of the phase diagram of the ternary system Y–Fe–V at 773 K was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS) techniques. It consists of 9 single-phase regions, 16 two-phase regions and 8 three-phase regions. The ternary compound YFe12-xVx (1.5≤x≤2.7, space group I4/mmm) with Mn12Th-type structure was confirmed in this system. At 773 K, the maximum solid solubility of V in Fe, and YFe2, is about 23 at.%, and 3 at.%, respectively, Fe in V is about 22 at.%. And that of Y in Fe, FeV and V don′t exceed 1 at.%.

Evaluation of Solubility Limit of Carbon in Ni3AlC1-x

ABSTRACTIn order to clarify the phase stability of E21-type intermetallic carbides, the maximum solid solubility of carbon in Ni3AlC1-x was evaluated by taking into account the strain energy and the chemical energy for the formation of the Ni6C cluster (EM6C). It was found that the maximum carbon content calculated was 0 at.%C at EM6C≥0, 3.5 at.%C at EM6C = -5 kJ/mol, 6.5 at.%C at EM6C = -10 kJ/mol, 10 at.%C at EM6C = -15 kJ/mol and 13 at.%C at EM6C = -20 kJ/mol, respectively. Experimentally determined maximum carbon contents in Ni3Al in the literature can be explained when EM6C is ranged from -5 to -15 kJ/mol, and the solid solubility is found to be sensitive to EM6C. The attractive interaction between Ni and C seems to be due to covalent bonding. Similar attractive chemical interaction between transition metals and carbon must stabilize E21 phases.