1. Precautions for Steel Selection and Pretreatment:
During the steel rolling process, the tissue stress should be minimized to allow hydrogen to diffuse out of the steel plate.
For the processing of steel billets for glass-lined products, hot processing should be avoided as much as possible. Practice has shown that hot-pressed heads are more likely to produce "scale burst" than cold-worked cylinders, and the "red-simmered" and "hot-pressed" frames and "anchor feet" of agitators are more likely to produce "scale burst" than cold-worked tie bars and spindles. For this reason, when pre-burning these products, the temperature should be lowered and the time should be extended to allow hydrogen to be discharged as much as possible. If "scale burst" defects are found, they should be pre-burned once or more times, and "scale burst" will be reduced.
Second, change the operating environment, reduce the indoor air humidity, dry the powder layer and completely reduce the moisture. That is, reduce the concentration of hydrogen during the enameling process, thereby reducing the hydrogen pressure.
Third, in order to remove hydrogen from the base glaze in time, it is advisable to add some substances that will release gas during the firing process, and hydrogen attracts these gases to be discharged together, such as NaNO3, Na2CO3, CaF2, etc.
Fourth, increasing the firing range and extending the firing time are conducive to the precipitation of hydrogen and other gases.
Properly lowering the furnace temperature during the firing process and extending the firing time are better ways to overcome the occurrence of porcelain explosion and "scale explosion" in summer. However, it should be noted that if the base glaze is over-fired, the tendency of "scale explosion" will increase, because the oxide layer is too thick and the adhesion is weakened.
Fifth, the thickness of the porcelain layer is appropriately increased to reduce the tendency of "scale explosion", because the increase in thickness requires a large hydrogen pressure to make the porcelain layer fall off. However, if it is too thick, the porcelain layer will have poor elasticity and increase permanent stress, which will cause porcelain explosion. To overcome "scale explosion", it is necessary to shorten the enameling cycle of the product as much as possible, and it is required to reach the required thickness of the product in the shortest possible time.
In addition, the product structure, the thickness of the iron billet, whether it is double-sided or single-sided enameling are all directly related to "scale explosion". Therefore, different measures and methods should be taken to prevent and control the product.
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