CE_Computer Instruction Manual:
◆ System Configaration
Set targets
You can set any number of targets, using mouse pointer to click a button on the screen. Then key-in material name and press [Enter]..
Pointing mouse arrow at the cell to be keyed-in, and press the select button of mouse. Then you can key in numbers with your keyboard.
◆ C% Si% offset C% & Si% displayed on monitor can be modified to get closer to the results obtained from spectrometer. Note that “displayed value = calculated value + offset value”. If displayed value is higher than spectrometer value, add a “-“ sign in front of the offset number.
Note: each iron should has its own offset value.
Re-check: After putting in an offset value, you can recall a curve to see NEW values of Si% or C% on the screen.
Weight for calculation Key-in 1000 Kg for a one ton furnace.
Print Select : Auto-Print will print out after each pouring of the CE cup.; print option: 1.Curve+Data, or 2. Data only. Manual print means after re-display of a curve, it will print the curve only at your pressing the “print” button.
◆C, Si measurement Pour iron melt from sampling scoop to CE cup. Watch out for melt temp. in cup. Too high a temp. will burn the sensor wire in cup. Too low a temp. will not obtain a “flat” TE plateau on the cooling curve. A Tmax in cup between 1250~1300 is most desirable. Pour the melt onto the inner wall of cup instead of onto glass tube directly.
◆ Curve Review
◆
Curves will be save automatically to the directory or file 00000001 up to 80 curves. Then, it will automatically create file 00000002 to save No. 81 and so on. To see history curves, double click the curve file of interest and then select the file of interest and “open” it.
◆ Trends of C, Si Each test result of CE, C, Si will be plotted on curve to show its trend
◆ Information ? This contains instruction manual and some metallurgy-related information
◆ Exit .Select -->Win_98
Note: The manufacturing tolerance of sensor wire in cup is +/- 4 C for precision grade. Watch out for this when new cups arrive. Pour a new cup and old cup for comparassion and rectify the difference in you computer.:
Temp lower by 1 C ---> C (or CE) increases 0.01 % but Si will increase by the amout of 0.05%
Temp 5C lower ---> FC will be 10 lower, for example 260 to 250,
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A. Notes on using CE_Computer:
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0. Tellurium in cup is aiming at creating a “white” eutectic freezing of the melt in the cup. Sampling scoop should not brushed with graphite because graphite help “gray” eutectic freezing and as a result, you do not obtain a Si% reading.
1. Pour the cup >90% full each time..
2. Avoid direct blowing of fan to cup during testing
3. Tmax in cup should be between 1250 C~ 1300 C. Too low, Tellurium will not be absorbed into the melt and it will freeze “grey” and “No Good”. Too high, sensor wire will be burnt. Melting point of sensor wire is only 1350 C.
4. The frozen lumps of sampling iron can be returned to furnace little by little, say 1 or 2 at a time. Do not put too many of them into a small furnace at one time because the strong white tendency of the Te.
5. The influence of each 1% of element on eutectic freezing temp (TE).
Cu: - 2. + means “increase”
Ni: - 6
Cr: + 7
Mn: + 3
P : -38 - means “decrease”
Si : - 20
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B. Cycle of program during CE measurement
Message line at the bottom of screen will prompt “ Open Circuit” if cup in not yet put onto cup seat. After a CE cup is put on it position, the temperature measuring circuit is closed and give program a room temp signal. Program will prompt “ Pour sample melt into CE cup”
The K type sensor wire in cup will tell computer the temperature in the cup in every 1/3 second. Once a melt is poured into the cup, temp curve will shoot up first, and drop steeply after peak temperature, Tmax. Then, when solid irons start to freeze out of melt, a short “flat” (TL) section of the cooling curve will be seen. After this, temperature drops less steeply until, again, a second flat (TE, much longer than previous one) section of the cooling curve appears.
At the appearance of TL, computer will tell CEL ( CE based on Liquidus temperature) and FC xxx. And after TE is detected, computer will tell Si%. At last, C% is separated from CE then. But the calculation in the computer is so fast that Si% and C% seem to appear at the same time.
If a cooling curve does not have a “pointed” peak, but has a “rounded” dome instead, the program will not be able to detect a TL correctly. And, it will show “ No Good ! “ on upper part of screen.
Very rarely, a TL is not detected on the correct position---flat region of cooling curve, then, use your own judgment. This happens if there is too little melt in cup, and that short TL flat section is too short to be detected by computer program.
Trouble shooting:
Cooling curve shoots up, and then nothing happen.
Possible causes: a. Sensor wire in the cup burnt because the pouring temp is too high.
b. Unstable seating of the cup on the cup connector.
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