钢铁锌系磷化液变黑原因分析及预防措施

Cause analysis and preventive measure of zinc series phosphating solution for iron and steel blackening

分析钢铁锌系磷化液在生产中变黑的原因和磷化液变黑的危害。磷化液变黑的主要原因是溶液成分配比不合理,工作负荷偏大,工作温度偏低,游离酸度偏高,促进剂浓度偏低和Fe2+浓度偏高等。给出预防磷化液变黑的措施:(1)设计时多配备1个磷化槽,以防止磷化液超负荷工作;(2)通入空气或加强磷化液搅拌;(3)对磷化液进行加热;(4)加强溶液的管理和溶液工艺参数的控制。

To analyze the cause of zinc series phosphating solution for iron and steel blackening in production and the dam- age of phosphating solution blackening. The primary cause of phosphating solution blackening is solution composition ratio is not reasonable, working load is heavy, working temperature is low, free acidity is high, promoting agent is low and iron ion concentration is high etc. The measures to prevent phosphating solution blackening were given： （ 1 ） to prepare one more phosphating bath when it is designed to prevent phosphating solution overloading production; （2） to blow air into the solution or strengthen phosphating solution mixing; （3） to heat the phosphating solution; （4） to strengthen solution man- agement and control of solution process parameters.