High silicon, low carbon austemperable cast iron

An austemperable cast iron, comprising:

• an ausferritic matrix including a combination of acicular ferrite and stable austenite supersaturated with carbon, the cast iron having a silicon content of from about 1.6 to about 2.4 weight percent, and a carbon content of from about 1.6 to about 2.2 weight percent, such that the carbon equivalent of said cast iron shall be from about 2.1 to about 3.0 weight percent, the ausferritic matrix being formed prior to cooling the cast iron to room temperature and before a substantial amount of bainite is formed so that as little bainite as possible is incorporated into the matrix.

An austemperable cast iron, comprising:

• an ausferritic matrix which includes a combination of acicular ferrite and stable austenite super saturated with carbon, the cast iron having a silicon content of about 1.8 weight percent, a carbon content of about 2.0 weight percent, and a manganese content of less than 0.3 weight percent, such that the carbon equivalent of the cast iron shall be about 2.6 weight percent, the ausferritic matrix being formed prior to cooling the cast iron to room temperature and before a substantial amount of bainite is formed so that as little bainite as possible is incorporated into the matrix.

An austemperable cast iron, comprising:

• an ausferritic matrix, the cast iron including a silicon content of nodular iron and a carbon content of malleable iron which forms a hybrid iron capable of being austempered, the ausferritic matrix being formed prior to cooling the cast iron to room temperature and before a substantial amount of bainite is formed so that as little bainite as possible is incorporated into the matrix.