Schmelzstrom

Schmelzstrom is a German term that can be translated as melting current. It refers to the electric current involved in heating a material to its melting point in electric heating applications. The concept is used to describe the current level that drives the phase change from solid to liquid through resistive heating or related heating methods.

The melting process depends on the electrical power applied and the material’s properties. The heat generated in the material is proportional to the square of the current times the electrical resistance (P = I²R). The energy required to reach and pass through the melting point includes both the sensible heat to raise the temperature to the fusion point and the latent heat of fusion for the phase change. The time to melt a sample thus depends on current, contact resistance, geometry, thermal losses to the surroundings, and the efficiency of heat transfer from the source to the material.

Schmelzstrom is a key parameter in various industrial and welding processes. In electric arc furnaces and induction furnaces, controlling the melting current affects melt rate, energy efficiency, and result quality. In fusion welding, the current level influences the depth of fusion and penetration. Safety considerations include electrode wear, overheating, and unintended arcing if the current is not properly controlled.

See also: Joule heating, melting point, latent heat of fusion.