Which galvanized sheet should I choose for indoor appliance linings (such as washing machines and refrigerators)?
Answer: Choose "electro-galvanized sheet." Reasons: Indoor environments are dry, so electro-galvanized sheet offers sufficient corrosion resistance. Its smooth surface makes it easy to shape into the lining. Its cost is lower than hot-dip galvanized sheet, meeting the cost requirements of home appliances.
Which galvanized sheet should I choose for outdoor steel structures (such as guardrails and billboard brackets)?
Answer: Choose "hot-dip galvanized sheet," with a zinc layer weight of ≥80g/m². Reasons: Outdoor environments are subject to rain and sun, and hot-dip galvanized sheet has a thicker zinc layer, stronger adhesion, and far superior corrosion resistance to electro-galvanized sheet. For coastal areas, "zinc-aluminum-magnesium sheet" (resists salt spray corrosion) is recommended.
What type of galvanized sheet is used for automotive body parts (such as doors and frames)?
A: Choose "hot-dip galvanized alloyed sheet" (iron is added to the zinc layer to form a zinc-iron alloy layer). Reasons: The alloyed layer has strong adhesion, making it suitable for automotive stamping and welding processes; it has high corrosion resistance, meeting the 5-10 year service life requirements of a vehicle; and it has a smooth surface, making it easy to paint (automotive topcoat adhesion is good).
Can galvanized sheet be used in food contact applications (such as food processing equipment housings)?
A: Directly using ordinary galvanized sheet is not recommended, as the zinc layer may fall off and contaminate food (excessive zinc intake is harmful to the human body). If necessary, choose "food-grade galvanized sheet" (the zinc layer is high-purity and free of heavy metal impurities), and apply a "food-grade coating" (such as a polytetrafluoroethylene coating) to isolate the zinc layer from the food.
Besides price, what other parameters should I consider when choosing galvanized sheet?
Answer: There are four core parameters to pay attention to: one is the type and weight of the zinc layer (hot-dip/electroplating, zinc layer weight); the second is the substrate material (such as Q235, SPCC, which affects strength and processing performance); the third is the surface treatment (whether it is passivated, the type of passivation, which affects corrosion resistance); and the fourth is the mechanical properties (yield strength, tensile strength, bending performance, to match processing requirements).