The electrode paste sometimes has problems during use. In this case, most of them are the overlapping effects of multiple factors. Among them, the U-turn phenomenon is also relatively common.
Here, there are two situations that will not be discussed for the time being.
1. Operational factors during use (for example, carbon loss, erosion, etc.)
Two; loopholes in the production process (eg, different batches, inclusions, etc.)
Starting from the rationality of the process formula design, we focus on the following situations:
Let’s start with a phenomenon in our daily life. I think everyone has experienced such a thing; in the cold winter, we take a cold glass, and then pour hot water into the glass, what will happen What about the phenomenon? why?
As a result, it is well known. In rare cases, the wall of the glass cup is cracked; in severe cases, the bottom end of the glass completely falls off.
In fact, this is because when the glass is under thermal stress, the heated bottom of the glass and the non-heated wall of the glass will instantly generate temperature. At this time, if the glass material has poor thermal strain capacity, the heat cannot be taken away in time. The stress is too concentrated, so it will cause the glass to crack and even the bottom end to fall off.
Someone may ask, this has nothing to do with electrode paste!
After all, the glass cup and the electrode paste are both inorganic and non-metallic and have similarities.
We return our thinking to the submerged arc furnace. The electrode is like a glass, and the powerful current is like hot boiling water. However, there is another important factor that exacerbated the U-turn.
Therefore, we introduced a physical quantity: effect.
In order to improve the thermal shock resistance of the electrode paste, it should be considered from three aspects: reducing the generation of thermal stress, buffering the development of thermal stress, and enhancing the ability of thermal stress.
One, reduce the generation of thermal stress. Measures: high thermal conductivity, low coefficient of linear expansion and high strength (controversial)
Second, buffer the development of thermal stress. Method: low modulus of elasticity (controversial)
Third, enhance the ability of thermal stress. Ways: the addition of graphite material and the increase of the proportion, the appropriate increase of the size and proportion of the large-particle aggregate, the high volume density, the appropriate increase of the softening point of the asphalt, and the addition of additives with good thermal conductivity.