Benefits of using Steel Fibers and Organic Fibers in Refractory ...

are very resistant to the tendency of the material to fall apart on thermal cycling. Stainless steel fibers greatly improve the flexural strength of the castable. And this added increase in ductility contributes significantly to the thermal shock and spalling resistance of the material. The fibers generally used are in size varying between 0.1 to 0.4 mm2 in cross-section & 20-40 mm in length. For monolithic SS is used either high chrome or high chrome nickel steels available in the market with different grades. One reason commonly reported that the thermal shock resistance of castables is greatly increased through addition of SS fibers because these fibers act as crack arresters, preventing cracks propagating. This is also possible that the microcracks caused by a mismatch in thermal expansion coefficients of matrix and fibers dissipate energy from larger cracks propagating as a result of thermal stress. However percentage of these fibers added becomes important because of two reasons as it has a direct impact on the fluidity of the castable, then it may also cause mixing difficult due to fiber-balling when added beyond 3% by volume. Another critical factor will be the maximum application temperature for the castable that those fibers present in the castable can resist oxidation (since these fibers can not perform beyond their melting temperature).