Corrosion resistance of AISI 304 and 444 stainless steel pipes in sanitizing solutions of clean-in-place process

Abstract

Stainless steel (SS) is successfully used in food industries due to the characteristics of its surface, which is essential for the maintenance of the properties of food. Tanks and stainless steel pipes, which come into direct contact with food and drink, undergo a process of cleaning and disinfecting called CIP (Clean-in-Place). This method consists of automatic recirculation of a detergent solution for a controlled time followed by a rinsing with water, and finally a cleaning and sanitizing solution immersion. This work consists of investigating the corrosion resistance of stainless steels used in the food industry using sanitizing solutions employed in the CIP procedure, and using electrochemical techniques such as potentiodynamic anodic polarization and electrochemical impedance spectroscopy.

Bioinspired Aryldiazonium Carbohydrate Coatings: Reduced Adhesion of Foulants at Polymer and Stainless Steel Surfaces in a Marine Environment

“…In the case of SS316 and N6, surfaces were preactivated prior to functionalization. SS316 surfaces were preactivated in caustic hypochlorite (bleach) solutions; this treatment is known to have cleaning and oxidizing effects on SS316 surfaces. − N6 surfaces were pretreated by immersion in formaldehyde solutions, which are known to activate amide groups in polyamides via formation of N -methylol groups. ,, Preactivation treatments were found to increase surface hydrophilicity, as evident from a marked change in water contact angle (Figure ). The WCA of SS316 decreases from 69.8 to 44.5°, as expected from oxidative cleaning of adventitious organics and exposure of a hydrophilic oxide film .…”

“…SS316 surfaces were pre-activated in caustic hypochlorite (bleach) solutions; this treatment is known to have cleaning and oxidising effects on SS316 surfaces. [38][39][40] N6 surfaces were pre-treated by immersion in formaldehyde solutions, which are known to activate amide groups in polyamides via formation of N-methylol groups. 36,41,42 Pre-activation treatments were found to increase surface hydrophilicity as evident from a marked change in water contact angle ( Figure 2).…”

Efficiency of cationic gemini surfactants with 3-azamethylpentamethylene spacer as corrosion inhibitors for stainless steel in hydrochloric acid

“…Corrosion in acidic environments is a serious problem in petrochemical, marine or chemical production [37,38] due to the use of hydrochloric acid solutions [29] for cleaning, pickling, descaling or oil well acidification [26,39]. Every year corrosion results in huge economic losses, decreasing operation efficiency and increasing the risk of accidents [40].…”

Study of imitative micro pit morphology evaluation

“…In the food and beverage industries, a wide variety of tanks and piping is used for the hygienic manufacture of food products. Most of this equipment is fabricated from austenitic stainless steel [1][2][3] and is usually built or produced from thin sheet stainless steel [4,5]. In the production process for food processing, it is essential to use clean-in-place (CIP), a method of cleaning the interior surfaces of pipes, tanks, processing equipment, filters, and associated fittings without disassembly to remove fouling deposits, which is essential to help avoid the cross-contamination of food when various products come into contact with the same surfaces as well as to prevent the growth of microorganisms.…”

“…To eliminate bacteria from surfaces and equipment, it is imperative to adopt effective cleaning and sanitization programs. Most sanitizers are corrosive to metals [5]. Pitting corrosion can occur when the local breakdown of the passive film layer occurs in an aqueous solution.…”