Graphite acts as a void and reduces strength. Higher strength irons more expensive to produce. Enables casting formerly produced in unalloyed grey cast iron to be used in higher duty applications without redesign or need for costly materials. Reduction in section sensitivity. Improvement in strength, corrosion resistance, heat and wear resistance or combination of these properties.
Limitations are higher cost.
Cr, Mo, V are carbide stabilizers which improve strength and heat resistance but impair machinability. Decarburised layer improves weldability and provides soft ductile surface to absorb local impact blows. Marked increase in shock resistance above 100 C. Used in furnaces up to 450 C. Can be galvanised and does not suffer galvanising embrittlement. Can be bronzed or bronze-welded. Very good machinability - high metal removal rates.