Taking on the ocean can be a daunting prospect, and for those who rely on it to earn their living, the challenge is even tougher.
Marine corrosion is a significant issue that can cost a business a considerable amount. One such reference to this issue is choosing the type of metal used in seawater settings. Each option has its advantages and disadvantages; and includes such factors as effectiveness, cost, and overall suitability.
In most cases, repair is the more cost-effective solution for maintaining and protecting metal parts in a marine environment, and this is where VRC Metal Systems can help. Rather than go to the expense of replacing an entire component or item, fixes such as cold spray application can be completed in place, offering the part a new lease on life.
Just how does this work? Read on to discover everything you need to know about cold spray applications and how to transform the repair and maintenance expectations for your business.
What Causes Corrosion?
Corrosion caused by seawater is an aqueous corrosion mechanism. In the simplest terms, when any alloy or metal comes into contact with seawater, there is a specific corrosion potential or electric potential created. As a result, there is an oxidation reaction driven by the potential difference between the component and its surroundings.
The destruction is an electrochemical process. The process is also affected by the particular level of acidity or alkalinity in the water – also known as the pH.
Seawater is particularly corrosive, due to the high concentration of chloride ions contained in seawater. This fact means that those designing sea-going vessels and components need to be selective in their choice of materials.
Certain properties help to reduce the risk of corrosion significantly, and this depends on the overall electrochemical potential of a given material, as well as the characteristics of its oxide film. The oxide needs to be stable, self-healing, and tightly adherent in order to protect materials that otherwise would corrode more quickly.
An example of materials that are naturally resistant to corrosion is bronze and stainless steel, making these a perfect choice for the marine environment. However, other materials such as titanium or aluminum have excellent protective oxides, and so may also provide good performance in seawater.
The Best Materials
A few materials consistently come out on top when it comes to their suitability in ships, airplanes, pipelines, and essential components.
- Carbon Steel
Carbon steel is not necessarily the first metal you think of when it comes to corrosion-resistant materials. However, the amount of oxygen the item is exposed to directly correlates to its submersion depth. The less oxygen exposure, the more corrosion resistant the material becomes.
In addition, carbon steel is popular due to its ability to accept coatings, as well as its lower prices.
- Stainless Steel
Stainless steel is another popular choice, mainly due to its inherent corrosion resistance. Its corrosion resistance is generally brought about by high percentage additions of chromium to the steel.
However, there is still a risk of pitting corrosion. Increasing the chromium content will help manage this risk.
When it comes to a marine environment, certain alloys of aluminum perform better than others. Pure aluminum and many 5000 and 6000 series of aluminum alloys are commonly used for fresh and saltwater applications. Creating an anodized layer also helps to reduce the risk of corrosion.
- Copper-based alloys
Bronze, brass, and other copper-based alloys are great for resisting corrosion, and as a result, are often chosen as materials for the marine industry. Different combinations have different advantages.
Naval brass alloys, or admiralty brass, include 1% tin. Arsenical brass is another option. As the name suggests, it includes low amounts of arsenic to prevent corrosion.
In some cases, aluminum and/or nickel may also be added to boost resistance.
- Nickel-based alloys
A nickel-based alloy is one of the best weapons against corrosion, but its significant disadvantage is its high price tag. This pricing makes it less accessible to some businesses and individuals.
For this reason, it is more common to see nickel interspersed with other materials, such as bronze, brass, or other more cost-effective copper-based options.
Titanium has a strong reputation as one of the best anti-corrosives in the business. As a result, it is popular amongst marine design professionals.
It is considerably more expensive initially than other options. However, its longevity and resistance to seawater corrosion can make it a far more cost-effective option in the long term.
So What Can You Do?
If you are in the marine industry, the manufacture and repair of metal components will be what keeps your job going. Pipes, airplanes, and ships all require careful design and construction, and the choice of material is a key priority.
Wherever possible, repairing existing materials in place is often a more cost-effective solution for businesses than component replacement. This is where cold spray coatings can enter as a real game-changer.
All of the materials listed above can be deposited by cold spray. It can be used to either repair components with the same or similar material, or it can be used to apply a thin protective coating of a more expensive and corrosion-resistant material onto a corroding part.
What Is a Cold Spray Application?
As the name suggests, a cold spray coating is a process used to enhance existing material properties. Rather than constructing an entirely new part from titanium, add a titanium coating to the surface of the existing item. This provides the item with the anti-corrosive advantages of titanium, but at a fraction of the price.
Cold spray coatings come in a range of materials, including titanium, copper, and nickel. To construct a brand-new part solely from these can be very expensive.
So many engineers, repair personnel, and buyers search for a more affordable option. Cold spray can provide a lower-cost solution to increase the corrosion resistance and lifespan of these parts, offsetting the cost of a cold spray application.
We Can Help
VRC Metal Systems could be the answer you need. We manufacture and create the machines to get you started with cold spraying and supply essential components and services to get you in the game and keep your equipment running for years to come.
First, let VRC Metal Systems help you reduce your third-party outsourced costs when it comes to metal preparation and repair. Second, start saving by following the old adage – “an ounce of prevention is worth a pound of cure.”
Reduce the amount of corrosion that your product endures, and you can increase the lifespan of the item while saving your business’ hard-earned cash.
Cold spray technology allows you to utilize the best properties from the most expensive materials at a fraction of the price — a real game-changer. Contact VRC Metal Systems today for a free consultation, and see how you could take your marine-based business to the next level.