The uniformity of the resistivity of the heating tube is better:

The uniformity of resistivity means that the resistivity per meter and batch of electric heating alloy wire or strip or the resistance value per meter should be uniform, and the fluctuation range should be as small as possible. The uniformity of resistivity is related to many factors such as alloy smelting, casting billet, heat treatment, single weight of wire rod and so on.

The uniformity of resistivity of nickel-chromium and nickel-chromium-iron alloys is better than that of iron-chromium-aluminum alloys. The aluminum in the latter is prone to segregation during smelting and ingot casting (the phenomenon of uneven distribution of constituent elements in the alloy during crystallization) Called segregation), resulting in a decrease in the uniformity of the alloy.

The uniformity of resistivity is especially important for filaments and thin strips. Because they are mostly used to produce electric heating elements for household appliances in large quantities, if the uniformity of resistivity is poor, the power of each element will be different.