Normal Temperature

A: Phosphating agent is a chemical agent used for metal surface treatment. It mainly forms an insoluble phosphate film (phosphating film) on the metal surface through chemical reaction, which plays a role in rust prevention, improving coating adhesion and wear resistance. It is widely used in pre-treatment processes in the automotive, machinery, home appliance and other industries.

A: The main components include phosphates (such as zinc salts, manganese salts, iron salts), acids (mainly phosphoric acid), accelerators (nitrates, nitrites, etc.), complexing agents and additives. Different types of phosphating agents have different composition ratios. For example, zinc-based phosphating agents are mainly zinc phosphate, while iron-based phosphating agents are mainly ferrous phosphate.

A: When the phosphating agent comes into contact with the metal surface, it dissolves the metal through acid etching to produce ferrous ions; at the same time, phosphate reacts with metal ions to form insoluble phosphate crystals, which are deposited on the metal surface to form a porous phosphate film. The film layer forms a chemical bond with the metal substrate and subsequent coating to enhance the protective performance.

A: The service life of the phosphating solution depends on factors such as the processing volume, metal material, and process control. Under normal circumstances, the medium-temperature zinc-based phosphating solution can process 200-500㎡/m³. If sediment or concentration imbalance occurs frequently, the tank liquid needs to be replaced.

A: Store in a cool and dry place, avoid direct sunlight and high temperature (temperature ≤ 40℃).
Store in a sealed container to prevent water evaporation or impurities from mixing.
Different types of phosphating agents should be stored separately to avoid mixing.
The name, concentration and production date of the reagent barrel must be marked, and the first-in-first-out principle must be followed.

A: Phosphating agent protects by forming a phosphate film, which is porous and has strong bonding with the coating; chromium-free passivating agent (such as silane, zirconium salt) forms a nano-scale passivation film, which is more environmentally friendly, but its corrosion resistance and bonding with the coating are slightly inferior to phosphating film, and it is suitable for scenes with extremely high environmental protection requirements.