How to Prevent Rust

We’ve all seen rust, whether it’s the dirty-orange flaking off a fence or swing set and marking up your children’s clothes, to the brownish water flowing in houses with old plumbing. But rust isn’t just an annoyance with its unsightly appearance and tendency to stain. For iron equipment and structures, rust can become a real danger when allowed to progress unchecked. In cases such as the Genoa bridge collapse in August 2018, a lack of maintenance to prevent rust and corrosion can lead to deadly consequences.

When it comes to iron corrosion, the equation is simple: oxygen from air or water + iron = rust. The longer iron is left exposed to oxygen, the more quickly and completely it will rust. So when it comes to rust prevention, the best solution is to somehow attempt to keep these elements apart. These methods include:

Materials

A common choice is to attempt to avoid the issue from the start by using steel alloys, weathering steels, or other alloys which contain virtually no iron. These materials are either naturally resistant to rust, or manufactured to be as rust-free as possible. Stainless steel contains at least 11% chromium, which forms a protective film of chromium oxide preventing any further corrosion. Weathering steels may include up to 21% alloying elements like chromium, phosphorus, nickel and copper. In comparison to stainless, weathering steel will form a patina and begin to look to look orange and rusty. However, appearances can be deceiving: unlike the damaging rust formed on iron structures, the rust formed on weathering steel is actually beneficial. The alloying elements stop any internal corrosion with the rust as an outer layer.

Organic coatings

A simple and cost-effective method of preventing rust is paint. Covering a metal item in an overall coat of paint creates a physical barrier between the metal and oxygen. Oil-based paints are usually the preferred option since they contain no water. It’s also appealing because the oil paint adheres better, is durable, and will dry to a more even finish.

Powder coatings

Like paint, a powder coating creates a protective layer to prevent rust. Powders are commonly applied to the steel by using a compressed air sprayer. Once the powder particles are clinging to the object’s surface in an even layer, it’s ready to be heat-cured. This involved placing the object in a hot oven, which will melt and fuse the powder particles into a continuous coat. So while this method involves more time and expense than painting, the biggest advantage of powder coating is its durability. Not only is it rust-resistant, it’s more resistant to chipping, scratching and other wear due to the thermal bonding of the curing process.

Galvanization

Steel is galvanized by applying a layer of zinc, which provides two benefits: it forms a strong physical barrier, and if corrosion does occur, it will affect the outer zinc rather the metal underneath. For items such as car exteriors that will later be painted, electroplating galvanization is used to bond the zinc to the steel. The process will leave the metal with a soft, even shine. For hot-dipping galvanization, the steel is immersed in a bath of molten zinc and dries to a flat finish. Hot-dipped galvanized steel is often preferred for construction projects because the resulting zinc layer may be up to 5 to 10 times thicker with this process. With each layer of zinc comes more protection against rust.

Maintenance

No matter what material is chosen or coating applied, the best protection against rust will always involve continued routine maintenance. Any deposits and dirt on the metal should be cleaned on a regular basis. If any rust does form on the surface, it should be removed it as quickly as possible, with a protective coating applied or re-applied to the item. Neglect means even a structure as strong as a bridge can be destroyed from the corrosive effects of air, water and salt rusting the steel.

What is the Difference between Annealing and Tempering?

At first glance, it might be difficult to distinguish annealing from tempering. Both are heat treatments designed to alter the physical and mechanical properties of a metal, and both involve heating that metal and gradually cooling it. So what makes the annealing steel different, and what are the advantages of this process?

When it comes to annealing, it’s important to remember how dependent the process is on precision and control. Like tempering, annealing involves reheating quenched steel and then allowing it to cool. However, at each stage of the annealing process, careful oversight is crucial to producing the most high-quality result possible.

Annealing involves three separate stages:

  1.  Recovery: simply put, this is applying heat to soften the metal. To ensure the most even heat distribution, air should be allowed to circulate freely around the items being annealed. For this reason, the heating is most often done in large ovens which can be tightly sealed, raised to the desired temperature, and closely monitored. Recovery then occurs when the heat breaks down dislocations and other irregularities within the metal’s structure.
  1. Recrystallization: during this stage, the heat is raised to above the metal’s recrystallization temperature while still remaining just below its melting point. This means that new smaller grains are formed within the steel, replacing older grains with pre-existing stresses. So while the finished product will be less hard then it was before, the uniform structure of the new grains will give the steel more strength and resiliency.
  1.  Grain growth: this is the cooling stage of the annealing process. In contrast to tempering, which allows the steel to cool naturally at room temperature, the cooling of annealed metals must be highly controlled. To do this, cooling is often done by immersing the hot steel into a low-conductivity environment such as burying it in sand or ashes. It can also be done by switching off the oven and allowing the metal to slowly cool within the machinery’s fading heat. Whatever the method used, the aim is to have as slow and gradual a cooling process as possible. When fully cooled, the steel will now possess a more refined micro-structure. In real terms, this means it has more elasticity, so that it can take the stress of machining or grinding with far less risk of cracking.

While all heat treatments result in a strengthened alloy, annealing is crucial for items that have previously been cold worked. Cold working produces stresses within the metal, which annealing then helps to reverse by bringing it closer to the metal’s original properties. That means the benefits of annealing are twofold: eliminating as much residual stresses as possible while restoring its strength and ductility. So while tempering is used for products such as structural beams, the more ductile steel produced through annealing is found in items like mattress springs, wiring, and tools.

What is the Tempering Process?

Steel is a term we consider synonymous with strength. Having a steely glare, being tough as steel: both expressions used to describe someone who is hard, strong, and determined.

So then, it may surprise you to learn that untempered steel can be nearly as fragile as glass! Without the tempering process, any steel produced will be extremely hard but also quite brittle. If it remains this way, it would be too prone to breakage to use in most applications.

Tempering is a method of heat treatment used to increase the resilience of iron-based alloys such as steel. After an initial heat treatment has been done to boost the steel’s hardness, tempering then reduces some of that hardness to help improve its strength. The end result is a steel which is less brittle, with increased ductility and abrasion resistance.

The tempering process begins after the steel has gone through an initial hardening treatment. With hardening, steel is brought to very high temperatures just short of melting, and quenched to cool it as quickly as possible. This quenching essentially locks the steel’s crystal structure and creates a very hard material. Tempering is then done immediately afterwards; if left to sit after quenching, the risk of cracking within the material will increase. To temper the steel, it involves reheating it once again to a high temperature and cooling, but in a less extreme or abrupt way than with hardening. Once exposed to the desired temperature, the steady heat application helps to relieve any internal stresses within the steel. Finally, the metal is removed and allowed to cool naturally in still air. So perhaps the best way to imagine tempering is as though you were baking a cake: you’ll have the best result if you are careful to set the right temperature, length of time, and gradual cooling.

Adjusting the peak temperature for tempering allows you the opportunity to create a product for a specific need. There are 3 temperature range categories when tempering steel:

  1. Low temperature: this tempering will somewhat reduce the metal’s brittleness, while retaining its hardness. Steel produced this way is often used for case hardening components and cold work tools.
  1. Medium temperature: the heat used in this range will produce a more elastic product. This means it’s now a more machinable and formable metal, which can be shaped and worked without losing the original shape. This steel is often used to manufacture knives.
  1. High temperature: the higher the temperature used during the tempering process, the greater toughness that is given to the steel. This combination of resiliency and toughness makes it a good choice when producing structural steel and machine components.

Overall, it’s a rule that any hardened steel must be tempered. And without tempering, your stainless steel and other alloys won’t have the high level of ductility and weldability that we’ve come to expect from high quality materials.

Reliance Steel & Aluminum Co. Launches FastMetals E-Commerce Platform

LOS ANGELES, Feb. 19, 2020 (GLOBE NEWSWIRE) — Reliance Steel & Aluminum Co. (NYSE: RS) today announced the launch of its new e-commerce business, FastMetals, Inc. (www.fastmetals.com), which offers a catalogue pricing model for a diverse selection of metal products including carbon, stainless, aluminum and specialty alloy steels. Located in Massillon, Ohio, FastMetals ships nationwide and has direct access to Reliance’s vast network of metals service center locations which carry over 100,000 products.

“FastMetals was created in response to the growing demand for digital purchasing solutions from metalworkers of all backgrounds,” commented Jim Hoffman, President and Chief Executive Officer of Reliance. “Consistent with Reliance’s core business strategy, FastMetals specializes in small orders with quick-turn around and best-in-class customer service. We are excited to launch this new, innovative venture that differs from our traditional sales model as simply another option for customers to purchase metal from us. Many of our existing service centers presently offer online capabilities and continue to receive inquiries via phone, email or other means based on the individual customer’s preference. FastMetals is yet another channel to experience Reliance’s unique, customer-focused service.”

FastMetals’ model is tailored to smaller, specialized end-users including artists, fabricators, machine shops, hobbyists, and do-it-yourself practitioners. Customers can choose from standard shapes and sizes or select specific dimensions to satisfy unique project requirements. FastMetals provides instant pricing, same-day shipping, no minimum order quantity and direct fulfillment to the individual customer.

About Reliance Steel & Aluminum Co.
Reliance Steel & Aluminum Co. (NYSE:RS), headquartered in Los Angeles, California, is the largest metals service center company in North America. Through a network of more than 300 locations in 40 states and thirteen countries outside of the United States, Reliance provides value-added metals processing services and distributes a full line of over 100,000 metal products to more than 125,000 customers in a broad range of industries. Reliance focuses on small orders with quick turnaround and increasing levels of value-added processing. In 2018, Reliance’s average order size was $2,130, approximately 49% of orders included value-added processing and approximately 40% of orders were delivered within 24 hours. Reliance Steel & Aluminum Co.’s press releases and additional information are available on the Company’s website at www.rsac.com.


Brenda Miyamoto
Investor Relations
(213) 576-2428
investor@rsac.com

or Addo Investor Relations
(310) 829-5400