Do coating materials protect the concrete matrix in a chloride ion environment?

Furthermore, it can be observed that, for all samples, the use of coating materials extended the appearance of corrosion products, thus protecting the concrete matrix in a chloride ion environment. Figure 12 presents EP, BR, and BW concrete samples after the aging process, revealing visible physical damage in the coating materials.

Does chloride corrode stainless steel?

Chloride levels can further exacerbate pitting corrosion rates on stainless steel, including when using ferric chloride (FeCl3) as a flocculating agent or to reduce sulphides. Type 304 and 316 stainless are prone to excessive pitting corrosion with chloride levels >300 ppm, even in neutral pH solutions.

How do coatings & pretreatment suppliers help?

Coatings and pretreatment suppliers can assist this process by providing salt spray and other forms of physical property testing. Chemical suppliers offer a variety of aqueous cleaners and conversion coatings designed to prepare metal parts to receive powder coatings. These metal treatments are most typically applied in a multi-stage spray washer.

Does RO water improve coating performance?

RO water can improve coating performance and reduce pretreatment chemical usage when used as make-up water for chemical baths. However, DI water is preferable as a final rinse, because the typical purity of RO water falls short of levels required for best coating performance.

How does water saturation affect coatings?

When the coatings are subjected to water saturation, the moisture can gradually penetrate the material, causing it to undergo physical changes. The water may seep into the coating, leading to a swelling effect and subsequently causing the material to expand.

How much sulfate & chloride should be added to water?

Additionally, the total of combined chlorides and sulfates should not exceed 100 ppm. Although these recommended levels of water purity yield satisfactory performance for many applications, the research that follows will show that superior performance is possible with lower TDS.