Zinc Plating Vs. Powder Coating In Extreme Application Environments

Steel Part With Zinc Plating

Sheet metal products serve a vast array of purposes in modern society and are a common fixture in the manufacturing, industrial, and transportation industries. Among other beneficial properties, sheet metal displays excellent strength, durability, and longevity. Yet in certain environments, those properties can be compromised by corrosion and other forms of structural degradation.

Manufacturers frequently apply a surface coating to protect sheet metal from unwanted oxidation. Two of the most common protective strategies are zinc plating and powder coating. This article takes a closer look at what each of these methods entails, as well as the relative merits to consider when choosing between the two.

Zinc Plating

Zinc plating, one type of galvanization, involves applying a thin layer of zinc metal onto the surface of another metal through a process known as electrodeposition. The zinc forms a protective layer, physically preventing oxidative forces from corroding the surface of the base metal; this is often referred to as the substrate.

Many people mistakenly assume that the zinc itself remains completely immune to corrosive action. This is not the case, however. Zinc instead offers what is known as cathodic protection. In other words, the zinc makes itself available to corrosion, thus protecting the underlying substrate.

That said, zinc has a higher degree of natural corrosion resistance than steel. This resistance has to do with zinc’s ability to form basic carbonate films. The actual corrosion rate of zinc depends on environmental factors such as the amount of moisture present, how quickly the surface dries, and any industrial pollution that may be present.

The Zinc Plating Process

Zinc plating is a complex, multi-step process requiring a large amount of specialized equipment. The first step involves preparing the substrate with a thorough surface cleaning. If any debris, rust, or contaminants remain present, the zinc may fail to adhere properly. Substrate cleaning is usually accomplished with an alkaline detergent solution followed with an acid treatment to remove any corrosion.

The actual coating process takes place in an electrolyte solution known as the plating bath. This bath consists of the zinc itself—present as an ionic solution—as well as various other needed chemicals. The substrate is introduced to the plating bath in one of two ways. So-called barrel plating involves placing loose pieces directly in a barrel, where they encounter the plating bath.

Barrel plating offers quick and consistent results. Yet some parts are either too large or too fragile for this method. In that case, the substrate pieces are affixed to a rack plating system and immersed in the bath. In either case, an electrical current is then introduced to the plating bath, causing the electrodeposition process to lay down a layer of zinc on the substrate.

Powder Coating

Powder coating takes a much different approach to protect a substrate against corrosion. Whereas zinc plating works through cathodic protection, powder coating utilizes barrier layer protection. In other words, powder coating involves the formation of an impenetrable outer layer, which prevents water and other oxidizing materials from accessing the susceptible metal.

Powder coat is made up of a paint-like, organic material consisting of pigment and resin. These finely ground particles are given an electrostatic charge and then sprayed onto the substrate. The charge allows the particles to adhere to the surface. Heat is then applied in order to melt the particles, fusing them together in a continuous, uniform layer.

The Powder Coating Process

As with zinc plating, the powder coating process begins with a thorough chemical cleaning of the substrate. The goal is to remove any dust, grease, oil, rust, or other contaminants and ensure optimal adherence. Once the substrate is clean, the powder is applied using an electrostatic spray gun.

A pumping device sends powder from the feed hopper, through a series of hoses, to the spray gun. Not only does the spray gun direct the flow of powder, but it also imparts the electrostatic charge that allows the particles to stick to the metal. The application process usually happens inside a spray booth. A built-in powder recovery system collects any overspray and routes it back to the feed hopper.

Once the sheet metal substrate has been completely coated, the powder must be cured. This commonly takes place inside either convection or an infrared oven. At a certain temperature, the powder melts, flowing together into a continuous film. Chemical crosslinking soon follow before the coating hardens into a stable layer.

Zinc Plating and Powder Coating Compared

With the above overviews of the zinc plating and powder coating processes in mind, it’s time to take a closer look at the particular advantages and disadvantages of each method relative to one another.

Cost

Of the two methods, powder coating tends to be less expensive—at least in terms of material costs. Simply put, the organic materials used in powder coating don’t carry as high a price tag as the zinc used in plating. The process itself is also somewhat simpler, thus helping to keep equipment and maintenance costs down.

If durability and longevity of the finish are of primary importance, zinc plating proves to be the long-term cost-effective solution. This ultimately reduces future costs associated with either re-coating or outright component replacement.

Time of the Process

Zinc plating has a slight advantage over powder coating when it comes to processing time. Both techniques require similar time investments in terms of substrate preparation. Yet once the base metal is ready to go, the zinc plating process can proceed from start to finish in just a few minutes. After the component has been dipped in the zinc bath, it only needs to be rinsed and dried before it is ready to go.

Powder coating, by contrast, does require more of a time investment. Not only does the powder have to apply to the entire surface carefully, but the sheet metal must then be cured. Curing alone tends to require between 10 and 15 minutes. While this may not seem like a huge amount of time, it can significantly increase processing time over the course of a large batch of components.

Service Life and Durability

Neither powder coating nor zinc plating will prove ideal for every application. In protected environments, powder coating can provide protection nearly indefinitely. Yet if powder coating becomes cracked or otherwise damaged, corrosion will quickly set in. Even a small scratch will leave the underlying steel without any protection.

Zinc plating by contrast will continue to provide protection even if the surface becomes scratched or damaged. The nearby zinc will continue performing its role of cathodic protection, attracting corrosive agents and sparing the steel.

Does your application involve steel in high-temperature situations? In such cases, powder coating may deliver more reliable protection. To learn more about what it takes to design, manufacture, and protect high-quality sheet metal products, please contact the industry pros at Staub Manufacturing.

/by

Your Ultimate Guide to Different Types of Steel

types of steel

Steel in its various types is a vital component of the United States economy. As of January 2020, domestic steel production was at 1,928,000 tons — making steel one of the most widely consumed domestic manufacturing products. From buildings to medical equipment and vehicles, the world literally runs on steel products. But not all steel materials are made alike.

There are multiple steel types and alloys that each have unique properties — making them each suited to specific production goals. Some steels are sturdy and heavy, while other steels are ductile and versatile.

Frequently, our customers approach us regarding the best type of steel for their application. We put together this quick guide to help you navigate the language of steel. Of course, you may still have questions regarding the application. Feel free to reach out to us with any unique property needs so that we can help you find the right steel and manufacturer for your needs.

Carbon Steel

Technically, carbon steel is a metal alloy that contains both iron and carbon. But in the manufacturing industry, carbon steel is often defined in multiple ways. Both of the following constitutes a “carbon steel” in the metals market.

  • Steel that contains up to 2% carbon
  • Steel that does not contain any standard amounts of elements that would classify it as an “alloy steel” (e.g., cobalt, nickel, tungsten, molybdenum, titanium, zirconium, vanadium, chromium, etc.)

You may also notice the term “carbon steel” applied to steels with less than 0.4% copper or steels that have certain magnesium to copper contents, though those definitions are contested across industries. For the purposes of this, we’re talking about the first two definitions.

There are three ways that carbon steel is classified — low, medium, and high

Low Carbon Steel

Low carbon steel (or “mild carbon steel” or “plain carbon steel”) refers to carbon steels that have up to 0.30% carbon content. This is, by far, the most common type of steel on the metals market. There are a few reasons for this. For starters, low carbon steel is relatively inexpensive. Also, since the carbon content is lower than medium and high steels, low carbon steel is easy to form and is perfect for applications where tensile strength isn’t an immediate issue, such as structural beams.

Another benefit of low carbon steel is that its properties can be improved relatively easily by adding additional elements, such as magnesium. Low carbon steel is also an ideal choice for carburizing, which improves case hardness without impacting ductility or toughness.

What are some common uses for low carbon steel?

  • Structural components
  • Machinery
  • Pipes
  • Domestic appliances
  • Automobile components
  • Surgical instruments
  • Medical equipment
  • Wires
  • Bolts
  • Stampings
  • etc.

Core properties of low carbon steel:

  • Low cost
  • Low hardness
  • Mild strength
  • High machinability
  • Very high toughness
  • High ductility
  • High weldability

Medium Carbon Steel

Medium carbon steel refers to carbon steels that have between 0.31% and 0.60% carbon content and between 0.31% and 1.60% magnesium. One of the biggest benefits of medium carbon steel is its strength. However, that comes with some tradeoffs. Medium carbon steel has low ductility and toughness — making it more difficult to form and weld.

What are some common uses for medium carbon steel?

  • Machinery parts
  • Pressure structures
  • Cranks
  • Gears
  • Railway tracks

Core properties of medium carbon steel:

  • Low hardenability
  • Medium ductility
  • Average toughness
  • Medium strength
  • Medium weldability
  • Average machinability

High Carbon Steel

High carbon steel refers to carbon steels that have between 0.61% and 1.50% carbon content and between 0.31 and 0.90 magnesium. When it comes to hardness and toughness, high carbon steel is the carbon steel of choice. However, this comes at a tradeoff. It’s very difficult to weld, cut, or form high carbon steel.

What are some common uses for high carbon steel?

  • Railways
  • Bars
  • Spring steel
  • Plates
  • etc.

Core properties of high carbon steel:

  • Low hardenability
  • Low ductility
  • Reduced weldability
  • Low machinability
  • High toughness
  • High strength

Stainless Steel

While carbon steel is typically defined by its carbon content, stainless steel is defined by its 10.5% minimum chromium content. Like carbon steel, stainless steel also contains carbon and iron, but the extra chromium is the key that gives it its unique properties. One of the biggest benefits of stainless steel is that it protects the steel for oxidization — which degrades metals over time. Stainless steel is also identified by its sheen, a property provided by the chromium. You will often see stainless steel utilized in cookware, knives, and medical equipment.

Like carbon steel, there are various types of stainless steel, each with a unique market price and properties.

Austenitic Alloys

Stainless steel austenitic alloys are, by far, the most common types of stainless steel metals on the market. They resist oxidation, provide a unique look, and are non-magnetic (though they can become magnetic in certain circumstances).

There are two common austenitic alloy grades:

  • Grade 304
  • Grade 316

Grades of austenitic alloys also include 301, 302, 303, 309, and 321.

Ferritic Alloys

Stainless steel ferritic alloys are another semi-common stainless steel alloy. Unlike austenitic alloys, they are magnetic — lending them to applications where magnetism is necessary. These are typically the cheapest stainless steel alloys due to their relatively low nickel content.

There are two common ferritic alloy grades:

  • Grade 430
  • Grade 434

Martensitic Alloys

Stainless steel martensitic alloys are the least common stainless steel alloy. These alloys have incredible hardiness and toughness, but they have poor oxidation properties, making them only suited for applications that require incredible hardiness.

There is one common martensitic alloy grade:

  • Grade 420

Alloy Steels

The widest and most diverse range of steel alloys is “alloy steels.” These are made by combining carbon steel with various alloying elements to provide unique properties to each steel. There is an incredibly wide range of alloy steels, but some of the most common include:

  • Chromium
  • Cobalt
  • Molybdenum
  • Nickel
  • Tungsten
  • Vanadium

Due to the incredible variety of alloy steels, you can create steels with almost every possible property using alloy elements. That being said, some of these steels are relatively expensive.

Tooling Steels

The final steel group is tooling steels. These are steels used for tooling activities such as drilling. Commonly made up of molybdenum, vanadium, tungsten, and cobalt, tooling steels are heat-resistant, durable, and strong.

There are 6 grades of tool steel:

  • Air-hardening
  • Water-hardening
  • D-type
  • Hot-working
  • Shock-resisting types
  • Oil-hardening

Do You Need Steel?

Staub Manufacturing offers services using most of the steels listed above. If your company needs best-fit steel parts to manufacture high-quality products, contact us. We’re American ISO 9001:2105 certified manufacturers who are ready to help you deliver superior fabricated steel products.

/by

5 Reasons to Source Your Sheet Metal Products from an ISO 9001:2015 Certified Company

Operation Of Hydraulic Bending Machine With Forming Die By Skilled worker; ISO certified

Ensuring the sheet metal fabrications in your supply chain are sourced and manufactured through tight quality controls is crucial for manufacturers in today’s hyper-competitive production ecosystem. According to a Geodis survey, 28% of manufacturers are pressured by global competition, and a further 27% are having trouble adapting to consumer demands.

Consumers crave higher-quality products, and manufacturers demand quality controls that ensure regulatory compliance and consistency. To help combat these needs, the International Organization for Standardization (ISO) utilizes an international standard for quality management systems (QMS) that allows manufacturers and customers to find high-qualified manufacturers that follow best-practice QMS principles.

This standard — ISO 9001:2015 — is awarded to businesses that showcase a commitment to quality control principles and a willingness to iteratively improve their processes, year-over-year, to deliver a superior product. For OEMs and Tier 1 manufacturers looking to source sheet metal products in today’s demanding and increasingly-transparent supply chain, ISO 9001:2015 has become a beacon of hope.

What is ISO 9001:2015?

Established in 1987, ISO 9001 is a certification that acknowledges a company’s adherence to certain quality management system (QMS) standards. The International Organization for Standardization (ISO) — a national standards body comprised of over 160 countries — administers ISO certifications to businesses that emulate best-of-breed practices and the highest quality of management.

5 Reasons You Should Choose an ISO 9001:2015 Certified Sheet Metal Product Supplier

1. Standardized Quality

An integral component of ISO 9001:2015 is standardization. The road to achieving certification can take months — indeed, even years. Every business must prove its ability to produce and provide consistent products and services to its customers. To start, all processes under the ISO framework have to have a well-documented quality management system (QMS). From processes to procedures and work productions, ISO certified manufacturers follow strict quality control procedures that are consistent and standardized.

For the steel sheet consumers, this standardization means that OEMs and T1 manufacturers can expect high-quality products consistently — reducing headaches in the supply chain. You want to work with a manufacturer that can deliver a consistent product that allows you to create your own processes. Any inconsistencies in quality and production can quickly cripple your output and breed agitation between your business and your clients or customers.

2. Overall Reliability

ISO’s highly-structured framework provides built-in processes for data management, strategy execution, and quality control on both broad and granular matters in the process chain. This means manufacturers adhering to ISO frameworks consequently reduce waste and achieve objectives. Through robust and highly-architectured processes, ISO certified manufacturers have a clear pipeline of delivery that involves data analysis from the start and plans for failures.

This ability to adjust processes on the fly gives manufacturers the ability to provide superb reliability. Do you need additional orders placed? Do you have a new revenue stream that requires a significant sheet metal product commitment? ISO certified manufacturers have the processes in place to handle those rapid adjustments.

3. Constant Improvement

ISO certifications aren’t permanent. Not only do you have to identify weaknesses and implement better processes to become ISO certified, but the certification ensures that you have QMS in place to consistently improve upon those processes. We all want to work with supply chain players that are committed to long-term improvements — not just in-the-moment deliverables.

You want a relationship that lasts for years. Establishing solid partnerships can help you predict and react to changes in your industry without worrying about procurement.

4. Better Shipping Logistics

As consumers demand faster shipping, getting materials to your manufacturing plant on time is essential. But not all suppliers use the same shipping and logistics strategies. While many supply chain players are trying to reinvent the wheel and implement faux “Industry 4.0” strategies, ISO 9001:2015 provides frameworks for highly-tested and highly-repeatable processes. This means better shipping procedures backed by technology and smart data analysis.

5. Higher Levels of Credibility and Trust

ISO 9001:2015 is a globally recognized standard of quality for businesses. When you work with an ISO-certified manufacturer, you’re working with a company with the highest level of credibility and trust. For example, Staub would have never been able to maintain ISO certification if it wasn’t absolutely dedicated to creating best-of-breed production, procurement, and shipping. ISO certification should be the first thing you ask for when you’re evaluating a new sheet metal product supplier.

If they have the certification, you know that they’ve (at the very least) created systems to ensure quality. Of course, some ISO certified companies have superior production and material quality than others; the ISO certificate is the handshake that opens the door.

Staub Manufacturing is an ISO 9001:2015 Certified Sheet Metal Product Manufacturer

Do you want to work with a credible manufacturer you can trust to work hard, constantly improve, and provide you best-in-class customer service? Staub Manufacturing is an ISO 9001:2015 certified manufacturer that you can rely on. For us, ISO certification is just the beginning. Correspondingly, we go above-and-beyond our certification requirements, and we’re the hardest working sheet metal fabrications providers in the business. Are you ready to call us your supply chain partner? Contact us today to learn more about how we can help you help your clients.

/by