Limitation is that extra cost must be justified by high performance or longer life. Higher hardness and toughness than other types of white iron. Low carbon compositions have higher toughness but lower hardness. Limitations are cost of higher alloy content must be justified by improved performance or longer service. Stress relieving heat treatment necessary for optimum properties.
Limitation is high cost.
Like parts made from other metal and alloys, parts intenteded to be produced as gray irons castings must be evaluated for the specific service conditions before being approved for production. The automotive and agricultural industries are the major users of ductile iron castings. Almost 3x10e6 tonnes of ductile iron castings were produced in the in the United States in 1988. Because of economic advantage and high reliability, ductile iron is used for such critical automotive parts as crankshafts, front wheel spindle supports, complex shapes of steering knuckles, disk brake calipers, engine connecting rods, idler arms, wheel hubs, truck axles, suspension system parts, power transmission yokes, high-temperature applications for turbo housings and manifolds, and high security valves for many various applications. It can be rolled or spun to the desired shape or coined to the exact dimension.