SHS 9192 GMAW OAW represents a breakthrough in the development of hardfacing wires due to its ability to survive in extreme environments. SHS 9192 is a patented multicomponent, glass-forming iron-based steel alloy designed to replace and be superior to existing cored wire products including chrome carbide, complex carbides and tungsten carbides; stick weld material loaded with carbides; and tungsten carbide laden Teflon® sheet overlays traditionally used for high abrasion environments. When applied as a weld overlay, SHS 9192 deposits provide extreme resistance to abrasion while maintaining high toughness. While conventional weld overlay materials are macrocomposites containing hard particles and general carbides in a binder, SHS 9192 is unique since it starts with a uniform glass-forming melt chemistry which allows high undercooling to be achieved during welding. This results in considerable refinement of the microstructure down to the micron and submicron range.

Extreme Abrasion Resistance
SHS 9192 exhibits extreme abrasion resistance through the in situ formation of high volume fractions (i.e. 60% - 70%) of complex borocarbide phases. Conventional approaches to wire design incorporate hard particles in the core of the wire and are limited volumetrically to much lower fractions of hard particles which limit their wear performance. In wear resistance testing, mass loss of ≤ 0.08 g (+/- 0.01) in ASTM G65-04 abrasion tests for SHS 9192 is revolutionary in a weld wire product. This unmatched wear performance allows SHS 9192 to be used as an alterative for some severe wear applications currently dominated by 60% tungsten carbide PTAW materials, the previous benchmark weld material for wear performance.

Single Pass Hardness/Wear Resistance
SHS 9192 has been engineered so that while the same levels of dilution can be expected (~ 30%) based on the application method, the dilution layer itself retains maximum hardness and wear resistance after a short distance from the weld overlay interface (i.e. within 100 µm). This allows maximum hardness/wear resistance to develop in the first weld overlay pass while conventional weld materials need two or more passes to generate their best wear characteristics. Elevated temperature hardness measurements have shown 680 Vickers hardness (60 HRc) is maintained at 1100°F showing that SHS 9192 exhibits superior elevated temperature hardness. In extreme environments, SHS 9192 can be built up in as many passes as necessary for the application without a soft layer and with all overlay welds providing maximum service performance.

High Deposition Rate Application
SHS 9192 does not rely on the incorporation of hard particles in the interior of the sheath, but instead high volume fractions of borocarbide phases form in situ during welding. This allows high amperage and wire feed rates to be used during the weld overlay process. Competing tungsten carbide wire materials often specify much lower feed rates due to carbide breakdown and dissolution which limits deposition rate and increases costs.

Superior Combinations of Wear Resistance and Toughness
Superior wear resistance of SHS 9192 occurs from the in situ formation of high volume fraction of refined complex borocarbide phases. The borocarbide phases, which form during solidification, are completely wetted by the matrix and prevent premature pull-out delamination and crack nucleation. The refined nature of the borocarbide phases allows the reduction of stress concentration sites and the ductile matrix, which consists of α-Fe and γ-Fe phases, supplies effective crack blunting and bridging.

Hardness Retained in Elevated Temperatures
The effect of exposure to elevated temperature for NanoSteel's SHS 9192 GMAW and SHS 9700 GMAW wires can be seen in the figure to the right. SHS 9192 retains its hardness very well through temperatures of 1,000°F with only a small drop from the as welded hardness. SHS 9700 shows a larger drop initial drop in hardness but it then stays above 61 HRc through 1,000°F.

Weld Parameters
SHS 9192 GMAW OAW weld parameter development was done with a Miller Delta-Fab™ system. Small changes in parameters may need to be made with other systems. Weld parameters for each SHS 9192 wire variation are listed in the following table. The parameters result in very good weld overlays with a short arc-length resulting in smooth beads with good arc transfer in the short arc and small globular range. Minimal cross checking is obtained with no preheat which can be reduced significantly by preheating above 600°F. All wire versions are designed to weld without porosity with the cover gases listed for GMAW wires and with no cover gas for OAW wires. When using the recommended parameters, spatter can be kept to a minimum resulting in deposit efficiencies over 95%. With SHS 9192, high weave speeds and wide weave patterns are possible allowing for a wide range of overlay solutions to fit particular applications. Additionally, SHS 9192 exhibits exceptional multi-pass characteristics and can be welded to at least four passes allowing the build up of thick deposits up to 0.5” thick. In comparison to the much denser tungsten carbide weld overlays, the thickness of SHS 9192 deposits (and the resulting life) will be greater per pound of material deposited. SHS 9192 weld overlays are ferromagnetic, extremely hard, extremely tough and can be machined by high speed grinding. Without using preheat, SHS 9192 weld overlays will exhibit minimal stress relief surface cross checking with cracks that are generally spaced at approximately 3/4” to 1” spacing.