Q: We’ve been having trouble getting good 报道 in our immersion iron phosphate process before powder, 导致多次返工和不合规格的零件. 这个问题是在我们的供应商改用硬脂酸基润滑油的同时出现的, 所以我认为我们需要重新评估我们的清洁过程, 但不知道从哪里开始.

A. Iron phosphate chemistries and other pretreatment methods are designed to provide enhanced physical and performance properties to the finished part or surface. 这些 applications are employed in various industries — from automotive and aerospace to construction, 枪支, 以及其他-提高产品在现场的耐用性和可靠性. 而影响磷化涂层效果的因素有几个, adequate cleaning and surface preparation are paramount to ensuring that the coating is uniformly applied and effectively adhered.

The primary objective of any surface preparation is to ensure that the substrate is entirely free of organic and inorganic contaminates and otherwise address any characteristics hindering the development or quality of the impending phosphate application. Organic contaminants are characterized as carbon-based molecules; this includes natural and synthetic oils, 预先存在的防锈剂, 机械加工和金属加工液, 蜡, 润滑剂, 和更多的. Inorganic contaminants are another form of surface imperfection and a common inhibitor to effective coatings; these include mill and heat-treat scale, 母材表面氧化(腐蚀/生锈), 和污迹. The targeted removal of all present contaminants is a key aspect of a successful surface preparation and phosphate coating.

Cleaning and surface prep can be achieved mechanically, chemically, or through a combination of both. 机械方法包括喷砂和刷丝, 虽然这些都是有效的技巧, 对于许多澳门威尼斯人网上赌场来说，它们通常不实用或成本效益不高. Chemical applications use solvent or aqueous products to process and prepare parts at scale through batch or continuous cycles.

水性清洁剂种类繁多，配方和功能也各不相同, 通常是针对特定的应用或目的而设计的. 通常, the first level of classification or segregation would be based on the cleaner’s primary builder(s); consequently, 这也转化为它的相对酸度/碱度:

  • Acid-based cleaners are formulated using mineral and organic acids, resulting in pH levels <6. 这些清洁剂通常是, 但也不完全是, 用于有色金属基材应用，在除锈方面非常有效, 脱氧, 以及各种无机污染物的除垢.
  • 中性到温和碱性的清洁剂可以用大量的化学成分制成, 包括磷酸盐, 胺, 和硅酸盐. 这些清洁剂的pH值范围从大约6.5 to 10.5、一般都是多金属保险柜.
  • Caustic cleaners utilize sodium and/or potassium hydroxide and have pH levels >11; these are often very effective in cleaning ferrous substrates and are commonly used before phosphate coatings. Under the right operating conditions, these products can also effectively de-rust surface oxidation.

除了这些建筑商, aqueous cleaners possess a range of specialty components to address various contaminants. 有机土壤在水中的溶解度一般很低，甚至没有, so aqueous cleaning applications employ surfactant packages to increase their solubility and remove them from the substrate. 腐蚀性清洁剂还能促进皂化的化学反应, whereby larger organic molecules (soils) are cleaved into fatty acid salts or soaps. 另外, 清洁剂可以使用其他几种试剂来提供诸如螯合作用等特性, 封存, 轻度防腐, 光明, 和更多的.

除了清洁剂的化学成分, three vital operating parameters play a critical role in the cleaner’s performance: time, 温度, 和浓度. 这些 parameters are direct variables to balance the application’s needs and limitations. Phosphate baths typically use caustic-based cleaners as the substrates are customarily ferrous and caustic cleaners tend to be the most robust. Immersion time is typically in the range of 5-10 minutes but can extend as necessary. 温度也是多变的, with operating ranges from 150°F up to 200°F; 温度s at the top of that range can be required for more tenacious materials such as stearate lubes and polymeric compounds. 最后, concentration also influences the efficiency and activity — immersion cleaners typically run at 5-10% v/v but can be run at up to 20% v/v for applications where corrosion or extensive contamination is present. 修改这些参数中的任何一个都可以提高清洗性能, 反过来, 改善磷酸盐的晶体形成, 报道, 以及附着力.

其他 aspects worth assessment include the set-up and maintenance of the cleaning operation. 浸入式清洗剂可以是乳化的，也可以是油裂解的. Emulsifying cleaners are ideal for barrel-processed parts and are functional until the surfactant capacity is saturated. 相反, oil-splitting cleaners are preferred for racked parts and in applications where considerable organic contaminants are being removed. The fixturing with respect to the part’s geometry can also impact the cleaner’s performance as recessed areas and concavities need adequate solution contact and flushing action. Active filtration of the cleaning solution ensures that the bath does not become oversaturated with soil. 最后，洗浴保养无疑是不容忽视的. 每日检查体温, 浓度滴定, and visual inspection of the cleaning solution ensure that work is processed consistently according to your application’s specifications. Judicious care for the daily operations of the cleaner baths translates to mitigated periodic maintenance as bath quality is kept in spec, 导致很少的浴缸倾倒和水箱清洗. 这些, 等, are all influencing factors to be aware of in evaluating and troubleshooting a cleaner issue.

Considering the totality of the cleaning application and understanding the variables in effect is crucial to evaluating and troubleshooting any cleaning issue. 每个澳门威尼斯人网上赌场都是独一无二的, 从正在使用的设备, 零件的基材和几何形状, 到需要处理的污染物. 经常, a minor adjustment in the operating parameters or fixturing can address the issue; other times, 有更多实质性的变化, 您可能需要考虑更适合您的应用的替代化学品. Consult your chemical supplier for troubleshooting guidance and product input whenever in doubt.