Warmverzinken

Warmverzinken, also known as warm galvanizing, is a metal finishing process that applies a protective zinc coating to steel or iron substrates at elevated temperatures, typically between 300 °C and 360 °C. The process involves a thermal immersion of the workpiece in molten zinc, which results in the formation of a metallurgical bond and a layer of zinc alloy. Unlike hot dip galvanizing, which uses a zinc bath at temperatures above 450 °C, warm galvanizing operates at lower temperatures, allowing for better control of coating thickness and reduced distortion of the base material.

The primary purpose of warm verZinken is to provide corrosion resistance while minimizing the thermal impact on heat-sensitive components such as stamped parts or molded plastics. The zinc coatings produced are generally thinner than those from hot dip galvanizing, typically ranging from 20 µm to 60 µm, depending on the application and the immersion time. At these thicknesses, uniformity and mechanical adhesion are key performance indicators.

Typical applications for warm galvanizing include automotive trim, hand tools, light gauge structural components, and kitchen appliances. The process is favored for parts that must retain dimensional precision or that contain non-metallic fillers that would melt or warp at higher temperatures. Common equipment used comprises a heat-treated zinc melt vessel, a charging system, and a cooling rig to solidify the bonded coating.

While warm galvanizing offers benefits such as lower energy consumption and improved tolerance for heat-sensitive substrates, it also has disadvantages. Coatings can be more susceptible to galvanic corrosion in certain environments, and the process requires stringent temperature control to avoid zinc embrittlement. Overall, warm galvanizing remains a widely used technique for delivering protective zinc coatings where high-temperature dip galvanizing is impractical.