Advanced Analysis for Gray Iron Microanalysis
While Basic and Simple Basic contained tests often addressed in past research, Advanced Information includes most all reported inflection points and calculations and some new ones as well. These points are based on derivatives or changes in the acceleration and deceleration of heat production. These can be seen by turning on higher order derivatives in the Curve configuration module. At this level, derivatives two through 5 are provided as well as the temperature curve and the rate of cooling curve.

Advanced Option Microanalysis Curves
⦁ Temperature Curve is the basic data gathered by the thermal couple.
⦁ Cooling Rate Curve is the instantaneous change in temperature.
⦁ The Lard Cooling option gives the Cooling Rate curve 50% of the curve window.
⦁ Derivative 2 shows inflections in the Rate of Cooling increasing magnification to typically 300x.
⦁ Derivative 3 shows inflections in the 2nd derivative curve further increasing magnification to typically 3000x or more.
⦁ Derivatives 4 and 5 likewise show energy activity at higher and higher magnifications reaching well over 10,000x in sensitivity.

Information and Variables of Advanced Microanalysis of Gray Iron
⦁ Start of Thermal Analysis is the point at which the thermocouple has stabilized with the metal. All arrest points excluding Maximum Temperature will occur after this point.
⦁ 1st, 2nd and 3rd Oxide Attests are arrests consisting of Iron Oxide and Silicon Oxide commonly called Mullite. Oxide arrests are from oxygen retained in the metal from rusty scrap. Oxides will react with your inoculant and lessen their effectiveness unless countered by the calcium content of your inoculant. High oxide levels in the iron will result in burn-on.
⦁ Liquidus Undercooling rarely happens but we have included it for people who might make strange irons. It occurs frequently in Aluminum and Steel, but not so often in iron.
⦁ Liquid Growth temperature goes with Liquidus undercooling and the same situation as mentioned in the undercooling.
⦁ Liquidus recalescence is the Liquidus Growth temperature – the Liquidus Undercooling Temperature.
⦁ The Rigidity point is the highest rate of cooling between Liquidus and Eutectic. Here is where the eutectic material first starts to slowly grow. It is also where pre-eutectic carbides grow.
⦁ Pre-eutectic arrests can be several things: early graphite/austenite, carbides or unknows we are still investigating.
⦁ Eutectic Gas are larger bubbles that form from entrained gases.
⦁ End of Eutectic Growth is the point of maximum stress where the energy production falls off.
⦁ Start of Solidus is where the zero or base-line curve intersects the cooling rate curve. It defines the start of the solidus energy adsorption.
⦁ Chill is a calculated chill based on local foundry research into the chill potential of an iron.
⦁ Eutectic Carbides are small carbides that form late into the eutectic. This is different from the massive carbides formed in White Iron.
⦁ Shrink 1st, 2nd and 3rd small macro-shrinks often appear in a series of tiny arrests. These are indicated, Large shrink is more obvious and will also be indicated. The next level goes into this in depth.
⦁ Hat Treat index is the difference between Eutectic and Solidus in degrees C. If the casting is to go through solution heat-treat to make ADI, a maximum of 25 degrees C is recommended by Advanced Process Corporation,
⦁ Solidification mode can be hypoeutectic, eutectic, hypereutectic or hypo and hypereutectic.
⦁ Cup freezing test is the time in seconds for the temperature to fall from the first to the second temperature as set by the user. Generally, we set the start and stop temperatures to bound the eutectic arrest. If ranges are set, then the percent of the midpoint of the range is displayed.
⦁ Eutectic Freezing is the Eutectic temperature – the Solidus temperature.
⦁ Total Freezing is the Liquidus Temperature – the Solidus temperature.

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