Method and apparatus for predicting microstructure of cast iron
AssigneeQueen's University
InventorsZhu Pan Ping, Reginald W. Smith
Life of this patent
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Abstract
A method and apparatus for predicting nodularity of a hypo or hyper eutectic cast iron melt during casting is described. The method is particularly useful for NiMg-treated melts but can also be used for rare earth treated melts. A small sample of the melt is poured into a sample cup to which up to 0.025% wt bismuth is added and a cooling curve is produced during cooling. In a NiMg treated melt, a .DELTA.T (TER-TEU) of at least 9.degree. C. indicates good nodularity. In an RE treated melt, a .DELTA.T of less than 6.degree. C. at a TER/TEU of 1140.degree. C. also indicates good nodularity will be observed upon the solidification of the melt.
Claims11
A method for predicting nodularity of a cast iron melt treated with a nodularizing agent, comprising:
- (a) providing a ceramic test cup which includes bismuth in an amount in the range 0.005-0.025% by wt of a sample of said melt;
- (b) introducing said sample into said cup;
- (c) measuring the temperature of said sample at selected intervals of time so as to produce a cooling curve for said sample;
- and
- (d) determining the difference (.DELTA.T) between a eutectic recalescence temperature (TER) and a eutectic undercooling temperature (TEU) for said cooling curve, and predicting a degree of nodularity therefrom.
A ceramic test cup having a cavity for receiving, when full, a selected weight of molten cast iron, said cavity containing bismuth in an amount in the range of 0.005-0.025% by weight of said selected weight of molten cast iron.
Apparatus for measuring a eutectic recalescence temperature (TER) and a eutectic undercooling temperature (TEU) in a cooling cast iron melt which has been treated with a nodularizing agent, comprising:
- test cup means having a cavity for receiving, when full, a selected weight of liquid cast iron;
- said cavity containing bismuth in an amount in the range of 0.005-0.025% by weight of said selected weight of liquid cast iron;
- thermocouple means;
- and means connected to said thermocouple means to read and record temperature in said cooling cast iron melt at selected intervals of time so as to produce a cooling rate curve for said cast iron melt, including said TER and TEU, the difference between which provides a measure of nodularity in said cast iron melt upon solidification.
Dependencies are inferred from the claim text.