Container Anti-corrosion Coatings

I. Importance of Corrosion Protection for Containers

Containers, as the primary equipment for global transportation, play a crucial role in international freight transport. Ocean transport is one of the main methods for container transportation. Containers used in ocean transport are exposed to the marine environment for extended periods, especially those loaded on the decks of container vessels, which are susceptible to corrosion from the marine atmospheric environment. This can shorten the service life of containers and increase maintenance costs.

Based on the characteristics of the marine atmospheric environment and an analysis of the principles of metal corrosion in this environment, the use of coatings for corrosion protection helps reduce the corrosive effects of the marine atmosphere on ocean transport containers. This serves to protect the container equipment and extend its service life.

Reference Standards

I. Reference Standards

Current national standards, relevant regulations, and mandatory standard provisions;

"Code for Construction and Acceptance of Building Anti-corrosion Engineering" (GB50212-2002)

"Standard for Corrosion and Rust Removal Levels of Steel Surface Before Coating" (GB8923-1988)

"Safety Regulations for Coating Operations and Safety Management Rules" (GB6514-1995)

"Quality Requirements for Anti-corrosion Coatings" (GB6514-1991)

"Safety Regulations for Coating Operations, Paint Process Safety, and Ventilation Purification" (DJ/T6931-1999)

"Code for Construction and Acceptance of Industrial Equipment and Pipeline Anti-corrosion Engineering" (HGJ229-91)

"Safety Regulations for Coating Operations and Safety of Surface Preparation Process" (GB7692-87)

"Noise Limits at Construction Sites" (GB12523-90)

ISO9001 Quality Management System Documents

ISO14001 Environmental Management System Documents

GB/T28001 Occupational Health and Safety Management System Documents

Design Basis

I. Design Basis

Environmental Conditions: The corrosion level of atmospheric environments on steel structures can be determined according to Table 1.

Atmospheric Corrosivity Classification and Typical Environmental Cases
Corrosivity Level	Mass and Thickness Loss per Unit Area (After one year of exposure)				Typical Environmental Cases in Temperate Climate (For Reference Only)
	Carbon Steel		Zinc		External	Internal
	Mass Loss	Thickness Loss	Mass Loss	Thickness Loss
	/g·m2	/um	/g·m2	/um
C1 Very Low	≤10	≤1.3	≤0.7	≤0.1	/	Interior of heated buildings with clean air, such as offices, shops, schools, and hotels
C2 Low	＞100-200	＞1.3-25	＞0.7-5	＞0.1-0.7	Atmosphere with low pollution level, mostly rural areas	Non-heated buildings with potential for condensation (such as warehouses, gyms, etc.)
C3 Medium	＞200-300	＞25-50	＞5-15	＞0.7-2.1	Urban and industrial atmospheres with moderate sulfur dioxide pollution and low salinity coastal areas	Production plants with high temperature and some air pollution, such as food processing plants, laundries, wineries, dairy factories, etc.
C4 High	＞400-650	＞50-80	＞15-30	＞2.1-4.2	Industrial areas with medium salinity and coastal regions	Chemical plants, swimming pools, coastal ships, and shipyards
C5 Very High	＞650-1500	＞80-200	＞30-60	＞4.2-8.4	Industrial areas with high humidity and harsh weather, and high salinity coastal areas	Buildings and areas with condensation and high pollution occurring continuously
CX Extreme	＞1500-5500	＞200-700	＞60-180	＞8.4-25	Offshore areas with high salinity and tropical/subtropical industrial areas with extremely high humidity and aggressive atmosphere	Industrial areas with extremely high humidity and corrosive atmosphere
Note: The loss values used to define the corrosivity levels are the same as those given in ISO 9223.

Energy Storage Cabinet / Energy Storage Container

I. Corrosion Protection for Energy Storage Containers

The corrosion threats faced by energy storage containers mainly originate from two aspects: first, natural environmental factors such as humidity, temperature fluctuations, ultraviolet radiation, and salt spray corrosion, which accelerate the oxidation process of metal surfaces; second, mechanical stress and chemical medium contact during use, which further exacerbates the corrosion process. These factors interact with each other like the sands in an hourglass, silently eroding the safety barrier of the equipment.

Table 1: Corrosion Protection for the Interior Surface of Energy Storage Containers

The corrosion protection process for the interior surface of energy storage containers should follow the following steps: first, the steel surface should be pre-treated, including sandblasting to ISO 8501-1, Sa2.5 standard, with surface roughness controlled at Rz 25-40μm. Next, the steel should be degreased to ensure good paint adhesion. After sandblasting, remove surface dust and residues. During painting, control the spray gun distance and movement speed to ensure uniform film thickness. Typically, an epoxy zinc-rich primer and epoxy topcoat system is used, with the primer providing rust protection and the topcoat meeting food hygiene safety requirements. After construction, allow leveling at an appropriate temperature for solvent evaporation. Finally, carefully inspect and repair any paint defects. This series of steps ensures long-term corrosion protection and safe use of the interior surface of the container.

Design Basis	ISO12944-5:2017 Protective Paint Systems for Steel Structures against Corrosion
Environment	C5 Very High; Internal: Condensation and high pollution continuously occurring and existing in buildings and areas
Design Lifespan	M Mid-term
Surface Treatment	ISO 8501-1 Sa2.5: Thorough blasting or shot blasting. The steel surface should be free of visible grease, dirt, scale, rust, paint coatings, and other contaminants, with any residual traces being light spots or streaks.
Coating Location	Interior Surface

Coating	Paint Type	Paint Name	Color	Thinner	A:B Ratio	Film Thickness
First Coat	DreamZinc	Graphene Zinc Powder Primer DreamZinc 30 Gns	Graphite Gray	Special Thinner DreamThinner 17 Gns	30.8:3.2	80
Second Coat	DreamCover	Graphene Low Surface Treatment Primer DreamCover 220 Gns	Gray, Light Gray	Special Thinner DreamThinner 17 Gns	25:5	120
Total						200

Table 2: Corrosion Protection for the Exterior Surface of Energy Storage Containers

During operation, energy storage containers may encounter chemical corrosion and electrochemical corrosion. Chemical corrosion is caused by direct chemical reactions between the metal surface and surrounding substances, such as the impact of acid rain and organic gases on metals. Electrochemical corrosion involves metal contact with electrolyte solutions, causing electrode reactions, especially in damp and cold environments. The main areas of corrosion include tank walls (affected by industrial atmosphere and impurities in the medium) and the tank bottom (one side in contact with the medium, the other side in contact with the soil, where sulfides, chlorides, oxygen, and other substances in the sediment water react with the metal). Localized corrosion is also common in tank roof depressions, weld seam recesses, areas prone to water ingress in insulation layers, and at the windproof ring and tank wall connections, where water tends to accumulate, leading to severe localized corrosion. To address these issues, energy storage containers should be designed and manufactured with corrosion protection measures, such as using corrosion-resistant materials, proper surface treatment and coating systems, and regular inspection and maintenance to ensure the long-term stable operation and safety of the containers.

Design Basis	ISO12944-5:2017 Protective Paint Systems for Steel Structures against Corrosion
Environment	C5 Very High; Internal: Condensation and high pollution continuously occurring and existing in buildings and areas
Design Lifespan	H Long-term
Surface Treatment	ISO 8501-1 Sa2.5: Thorough blasting or shot blasting. The steel surface should be free of visible grease, dirt, scale, rust, paint coatings, and other contaminants, with any residual traces being light spots or streaks.
Coating Location	Exterior Surface

Coating	Paint Type	Paint Name	Color	Thinner	A:B Ratio	Film Thickness
First Coat	DreamCover	Graphene Low Surface Treatment Primer DreamCover 220 Gns	Gray, Light Gray	Special Thinner DreamThinner 17 Gns	25:5	220
Second Coat	DreamDur	Acrylic Polyurethane Topcoat DreamDur 550	Customizable Color	Polyurethane Thinner DreamThinner 10	21.4:3.6	80
Total						300

Land Transport Containers: Main Frame, Inner Surface, Outer Surface Anti-Corrosion

Table 1: Corrosion Protection Scheme for the Main Frame and Inner Surface of the Road Transport Container

Design Basis	ISO12944-5:2017 Protective Paint Systems for Steel Structures against Corrosion – Paints and Varnishes
Environment	C4 high; Internal: chemical plants, swimming pools, coastal shipbuilding areas, etc.
Design Service Life	M Medium-term
Surface Preparation	ISO 8501-1 Sa2.5: Very thorough blasting or shot blasting to remove rust. The steel surface should be free of visible grease, dirt, mill scale, rust, paint layers, or any other contaminants. Any remaining marks should be light, spot-like or linear.
Coating Area	Main frame and inner surface

Coating	Paint Type	Paint Name	Color	Thinner	A:B Ratio	Film Thickness (µm)
First Coat	DreamCover	Graphene Low Surface Preparation Primer DreamCover 220 Gns	Grey, Light Grey	Special Thinner DreamThinner 17 Gns	25:5	180
Total						180

Table 2: Corrosion Protection Scheme for the Outer Surface of the Road Transport Container

Design Basis	ISO12944-5:2017 Protective Paint Systems for Steel Structures against Corrosion – Paints and Varnishes
Environment	C4 high; External: Medium-salinity industrial and coastal areas
Design Service Life	M Medium-term
Surface Preparation	ISO 8501-1 Sa2.5: Very thorough blasting or shot blasting to remove rust. The steel surface should be free of visible grease, dirt, mill scale, rust, paint layers, or any other contaminants. Any remaining marks should be light, spot-like or linear.
Coating Area	Outer surface

Coating	Paint Type	Paint Name	Color	Thinner	A:B Ratio	Film Thickness (µm)
First Coat	DreamZinc	Graphene Zinc Powder Primer DreamZinc 30 Gns	Graphite Grey	Special Thinner DreamThinner 17 Gns	30.8:3.2	100
Second Coat	DreamDur	Acrylic Polyurethane Finish DreamDur 550	Supports RAL and National Standard Coloring	Polyurethane Thinner DreamThinner 10	21.4:3.6	80
Total						180

Marine Shipping Containers

I. Corrosion Characteristics of Marine Atmosphere

The marine atmosphere contains a high level of salt mist, which has a strong corrosive effect on metals. From the perspective of corrosion, the marine atmosphere environment can be divided into five corrosion zones: marine atmosphere zone, splash zone, tidal zone, fully immersed seawater zone, and seabed soil zone. Among them, the marine atmosphere zone, which is close to the splash zone, has the greatest impact on metal corrosion. The ocean-going transport containers are in this zone; therefore, corrosion protection for these containers is particularly important.

II. Analysis of Corrosive Environment for the Inner Surface of Shipping Containers

The marine atmosphere is rich in a large amount of sea salt particles, forming an environment with high salt content gases, which is a key difference from other atmospheric environments. The salt particles dissolve in the water film on the metal surface, turning the film into a highly corrosive electrolyte, thus accelerating corrosion. Compared to the condensation water film in clean air, air saturated with sea mist can increase the corrosion rate of metals several times.

Table 1: Corrosion Protection Scheme for the Main Frame and Inner Surface of Shipping Containers

Design Basis	ISO12944-5:2017 Protective Paint Systems for Steel Structures Against Corrosion
Environmental Conditions	CX Extreme; Interior: Industrial areas with high humidity and aggressive atmospheric conditions
Design Life	VH Long-term
Surface Treatment	ISO 8501-1 Sa2.5: Very thorough shot-blasting or abrasive cleaning. No visible grease, dirt, mill scale, rust, paint coatings, etc., on the steel surface. Any residual marks are only slight, localized, or strip-like color spots.
Coating Location	Main frame, inner surface

Coating	Coating Type	Coating Name	Color	Diluent	A:B Mix Ratio	Film Thickness (μm)
First Layer	DreamZinc	Graphene Zinc Primer DreamZinc 30 Gns	Graphite Gray	Graphene-specific Diluent DreamThinner 17 Gns	30.8:3.2	80
Second Layer	DreamCover	Epoxy Zinc Rich Intermediate Paint DreamCover 150	Light Gray Mica Oxide	Epoxy Diluent DreamThinner 17	25.2:6.8	200
Total						280

Table 2: Corrosion Protection Scheme for the Outer Surface of Shipping Containers

Design Basis	ISO12944-5:2017 Protective Paint Systems for Steel Structures Against Corrosion
Environmental Conditions	CX Extreme; Exterior: Marine areas with high salinity and tropical and subtropical industrial regions with high humidity and aggressive atmosphere
Design Life	VH Long-term
Surface Treatment	ISO 8501-1 Sa2.5: Very thorough shot-blasting or abrasive cleaning. No visible grease, dirt, mill scale, rust, paint coatings, etc., on the steel surface. Any residual marks are only slight, localized, or strip-like color spots.
Coating Location	Main frame, inner surface

Coating	Coating Type	Coating Name	Color	Diluent	A:B Mix Ratio	Film Thickness (μm)
First Layer	DreamZinc	Graphene Zinc Primer DreamZinc 30 Gns	Graphite Gray	Graphene-specific Diluent DreamThinner 17 Gns	30.8:3.2	200
Second Layer	DreamDur	Polyurethane Finish Paint DreamDur 550	Support for Raul and National Standard Colors	Polyurethane Diluent DreamThinner 10	21.4:3.6	80
Total						280

Coating Solutions from mengneng product

Container Anti-Corrosion Solve