When using a thermal analyzer What to look out for when using a thermal analyzer: This article was published by Nanjing No.4 Analytical Instrument Co., Ltd. We are manufacturer of Truck Radial Repair Patch in China, if you want to buy Heavy Duty Truck Tire Patch Kit,Semi Truck Tire Repair Kit,Semi Truck Tire Patches please contact us. Truck Radial Repair Patch,Heavy Duty Truck Tire Patch Kit,Semi Truck Tire Repair Kit,Semi Truck Tire Patches KRONYO United Co., Ltd. , https://www.kronyoglue.com
First, the use of sample cups (a) For the analysis of the components, must be taken as the original iron liquid bred into the sample cup;
(b) The temperature of the molten iron is preferably higher than the initial crystal temperature of 50 degrees Celsius. If the temperature is low, the primary crystal temperature cannot be measured. If the temperature is too high, the thermocouple wire may be easily melted.
(c) The amount of molten iron required to fill the sample cup is 90% to 100% of the sample volume. If too little, the temperature plateau becomes steep and the correct feature point cannot be identified. When too little, the molten iron overflows to determine the composition and performance of the additive in the sample cup. Lost, it does not work. The amount of liquid iron in the determination of the rate of spheroidization also causes a change in the heat capacity of the cup.
(d) After the completion of a measurement, remove the used sample cup as soon as possible to avoid the increase in temperature of the sample holder and affect the measurement accuracy.
Second, the problem of abnormal cooling curve (a) cooling curve Tl obvious, but eutectic temperature rise, Ts test failed.
Causes: 1. The sample curve Tl or no Te; 2. Ferric trace elements in the interference (Ti); 3. fertility after fertility, a strong inoculation effect to offset the role of white elements.
(b) The cooling curve has no Tl point, but the Ts platform exists.
Reason: 1. The burning temperature is lower than the primary crystal temperature; 2. The iron liquid carbon equivalent is too high or too low, beyond the measuring range of the instrument.
(c) Supercooling of the primary crystal platform.
Cause: Some alloying elements emit a large amount of latent heat of crystallization during the primary phase. High Cr cast iron occurs in many cases.
Third, the instrument's grounding problem In the vicinity of high-power electrical equipment using thermal analysis instruments, the shape of the curve sometimes sawtooth or eutectic platform temperature drift occurs, resulting in measurement failure. At this time, the key issues of the shielded room of the compensation wire and the instrument must be made separately to ensure that the insulation resistance is less than 1Ω.
Fourth, the problem of alloy cast iron Special alloy cast iron, due to the content of alloying elements is too large, the effect of alloying elements on the cooling curve is greater than the impact of carbon, silicon in the metal liquid on the curve. Although the CE%, C%, and Si% are all within the measurement range of the instrument, the corresponding components of the iron fluid cannot be measured accurately. This happened in Shanghai, Guangzhou, Qinhuangdao and so on.
V. Other (a) High phosphorus cast iron issues: In high-phosphorus cast iron, the effect of phosphorus is equivalent to 1/3 of silicon, which has a great influence on the composition analysis of silicon and requires special treatment when used.
(b) During the smelting of cupolas, occasional eutectic re-growths, with the exception of a few white mouth elements missing or a decrease in the iron content of the whitening elements, most customers are caused by accidental changes in the trace elements in the charge.
(c) Some bred ferric liquids can also be measured directly with a whitening cup. However, after the strong inoculants are not used, they may not be measured and they need to be used before gestation.