Metal Sheet Stretching And Stamping; Gas Meter Box; Gas Meter Housing Stamping Parts; Stamping Dies

The appearance of white rust shortly after galvanizing is essentially a product of the oxidation reaction of the zinc layer under specific environmental conditions. It is not accidental; there are clear environmental and process-related factors behind it.

From an environmental perspective, humidity and temperature are two key drivers. When galvanized parts are processed and placed in an environment with a relative humidity exceeding 70%, moisture in the air will quickly condense on the zinc layer surface, forming a water film. This water film acts like an electrolyte solution, providing a breeding ground for the zinc oxidation reaction. Zinc reacts chemically with water and oxygen to produce loosely textured zinc hydroxide, which is the white rust we see. Simultaneously, sudden temperature changes in the processing workshop and storage area, with alternating hot and cold temperatures, will exacerbate the condensation and evaporation cycle of moisture, further accelerating the formation of white rust. This is a common environmental factor contributing to the appearance of white rust shortly after galvanizing.

Oversights in process control are also an important and undeniable factor. Some companies fail to perform necessary passivation treatment on the workpieces after galvanizing, leaving the zinc layer surface without a dense protective film. This direct exposure to air significantly reduces corrosion resistance, making it highly susceptible to white rust formation within a short period. Furthermore, if degreasing and rust removal are incomplete during the pretreatment stage of galvanizing, residual impurities on the workpiece surface can disrupt the uniformity of the zinc layer, leading to localized weaknesses in zinc layer protection and the rapid appearance of white rust. This is a key process-level factor contributing to the appearance of white rust shortly after galvanizing.

Regarding environmental control, a strict temperature and humidity control system is necessary. After galvanizing, workpieces should be immediately transferred to a dedicated storage area with constant temperature and humidity. Temperature and humidity monitoring equipment should be installed to ensure that the ambient humidity is stably controlled below 60% and the temperature is maintained within the suitable range of 15-25℃. If the overall humidity in the workshop is too high, industrial dehumidifiers can be used to dehumidify the processing and storage areas in real time, reducing moisture erosion of the zinc layer at the source and effectively preventing the environmental conditions for white rust formation shortly after galvanizing.

Process optimization is the core guarantee for avoiding white rust. Enterprises must strictly adhere to the full-process standards for galvanizing, ensuring thorough degreasing and rust removal during pretreatment to achieve a clean surface free of oil, rust, and oxide scale, laying the foundation for uniform zinc coating adhesion. Simultaneously, after galvanizing, passivation treatment must be performed promptly. This forms a dense passivation film on the zinc layer surface, preventing direct contact between air and moisture, significantly enhancing the zinc layer's corrosion resistance and fundamentally reducing the probability of white rust appearing shortly after galvanizing.