The use of steel has not been any less impactful in the world of automotives. Its ability to be machined and manufactured in various shapes through different techniques makes it a practical, cost-effective, and durable option. The types of steel used in the automotive industry can be anywhere from stainless steel, high-strength steel, high-carbon, low-carbon, or galvanized steel.
These types of steel are used in the production of various vehicle and engine components. Some examples are the following: bushings, bearings, exhaust pipes, radiators, car frames, chassis, wheel rims, and many more. There’s no disputing that steel has etched itself in the history of manufacturing as one of the most reliable materials out there.
To gain a better appreciation of a widely available, yet handy material, we look deeper into the top uses of various steel grades found in all types of automobiles. All of which allow carmakers to create new and innovative features for vehicles. Read on to learn more.
A steel raw material or pre-fabricated product can only have the “stainless” designation if it contains at least 10.5% of chromium, 1% carbon, alongside other alloying compounds. One striking feature of this steel type is its ability to resist corrosive materials. Its lustrous and light-bodied design has been synonymous with durability and functionality in many industries, not just vehicle manufacturing.
It makes sense that stainless steel would be one of the go-to materials for crafting and assembling different vehicle components together. In fact, many vehicles comprise around 15 to 2 kilograms of stainless steel found in their exhaust systems.
Fuel-combustion engines, in particular, require the use of materials that don’t easily deform or melt under high temperatures. Stainless steel is a perfect candidate for this due to its extremely high melting point of more than 1500 degrees Celsius. As you may already be familiar, the average vehicle when in use generates around 90 to 104°C in engine temperature. Having stainless steel components not only protects the rest of the driver while in motion but also ensures the safety of surrounding car materials.
Modern steel innovations have led to the development of a new grade of steel, known as advanced-high-strength steel, or simply AHSS. Unlike the typical low carbon and mild steel, AHSSs are sophisticated and complex. It’s made out of carefully selected materials with specific chemical compositions. The result is a precisely heated steel product that is tough, ductile, and has an exceptional fatigue rating.
Despite the properties present in AHHSs, they’re a preferred choice for vehicle bodies, frames, car doors, bumpers, and undercarriages due to their lightweight. Many car manufacturers nowadays are coming up with effective solutions to engineering AHHSs into a dependable automotive material that satisfies safety, cost, and performance.
This type of high-strength steel can be further classified into different families — martensitic (MS), ferritic-bainitic (FB), transformation-induced plasticity (TRIP), and twinning-induced plasticity (TWIP), to name a few. TRIP and DP steels, for example, are suitable for engine crash zones, or portions that require high energy absorption. Meanwhile, MS is instrumental in improving vehicle safety and performance.
Steels with high-carbon content, known as high-carbon steel are alloys that have undergone a heat treatment method known as quenching. Whereas in traditional heat treatment of steel wherein the carbon content is dissolved into the heated iron, the rapid cooling applied in quenched steel “traps” the carbon and transforms steel’s structuring.
Unlike ordinary steel, high-carbon steel is less ductile and prone to brittleness. However, this is offset by its high resistance to wear and tear, which is why high-carbon is often fabricated into cutting tools or metal fasteners.
With these properties in mind, carmakers have also consistently chosen high-carbon steel to fashion vehicle frames, chassis, bushings, door panels, support beams, mufflers, and the like. Combined with other grades of steel, the high-carbon variety can be used in the production of a vehicle that meets safety standards, crash requirements, and even design.
Unlike its high-carbon counterpart, low-carbon steel has a much lower tensile strength and poorer yield-point runout. Also referred to as mild steel, low-carbon steel, however, has continued to find its way into many vehicle parts because it is cheap to produce and is useful for the production of smaller components.
Low-carbon steel can be found both in the interior and exterior of the vehicle. Some examples are clutch housings, suspension parts, control arms, brackets, and the like. Its decorative uses may also range from wheel rims, covers, screws, washers, bolts, nuts, fasteners, and the like. All of these are essential in maintaining the structure and stability of any given vehicle.
Cheaper than stainless steel, but more effective than aluminum, galvanized steel is another popular use of this alloyed metal in vehicle-making. Today, the use of galvanized steel is even considered a standard in any type of vehicle. Almost 80% of a car, truck, or motorcycle can be made up of galvanized steel. Coated with a thin layer of zinc coating, this type of steel can extend the life and function of the vehicle with minimal repairs and maintenance required.
Some benefits of galvanized steel are its low cost, improved durability, self-healing, and availability. In place of expensive steel grades such as AHSS and high-carbon, the galvanized steel option can offer long-lasting protection for any part of the vehicle it has been used in.
Different types of steel used in the automotive industry can be found in almost every part of a vehicle. As discussed, some of these steel can provide good strength qualities to any car — such as the case with advanced high-strength steel and high-carbon steel. Other types are more cost-effective in nature. Stainless steel, galvanized steel, and low-carbon steel, for example, still offer ample strength with very few drawbacks.
As the automotive and the steel-making industry continue to innovate, like Metal Exponents as a top steel-making organization in the Philippines no doubt that manufacturers from both fields will continue to engineer specialty steel parts and products, further solidifying the role that steel plays in both sectors.
5 Types of Steel Used in The Automotive Industry
We don’t normally see stainless steel cars but Tesla’s making their new Cybertruck out of stainless steel. This is another bold move from a company that likes to rip up the rulebooks. You can read all about the Cybertruck here.
But is it actually a good idea?
Why has only one other stainless steel car been mass-produced, and that ended in bankruptcy? Will it be different for Tesla, or is the new Cybertruck a big white elephant?
An English metallurgist, Harry Brearly, was trying to improve rifle barrels just before the first world war. He found that adding chromium to steel inhibited its natural tendency to rust. This is because of a chromium-rich oxide coating that seals the metal from the elements.
But it wasn’t until the 1930s that people thought of using stainless steel on cars. The Allegheny Ludlum Steel company approached Ford Motor Company with the idea of a car to help them sell more stainless steel.
Ford obliged and produced 6 unpainted Ford Model 68 Deluxes. Allegheny Ludlum loaned them out each year to their top salesmen. The cars were on the road for ten years and each one of them logged in over 200,000 miles.
The shiny bodies are still in excellent condition, of course, and have held up better than the rusting steel chassis! Why the chassis was not made from stainless steel is a mystery.
But here’s the first reason as to why we don’t see more stainless steel cars on the road. A retired Allegheny Ludlum employee revealed that when the cars were originally produced the dies were ruined by stamping out the stainless steel parts from the harder material.
So, to produce cars from stainless steel, carmakers must spend additional money. Making dies that could withstand stamping out stainless steel parts day in, day out. The Tesla Cybertruck uses cold-rolled stainless steel. And that’s even harder than regular stainless steel, and this makes the problem even worse.
Ford agreed to another collaboration with Allegheny Ludlum in 1960 to produce two Ford Thunderbirds. These original 1936 cars had been very shiny. But with the update, they went for a brushed finish, and I’m sure other motorists thanked them for it!
After the issue with dies with the 1936 cars. Ford waited until the end of the car’s production run before damaging the dies producing the stainless steel cars! Again, Allegheny Ludlum used it to help publicize stainless steel and they toured the USA drumming up business.
The new cars used stainless steel exhausts and mufflers. They must be the only 1960s cars still around today with their original exhausts! Ford and Allegheny Ludlum collaborated one last time with three stainless steel 1967 Lincoln Continental convertibles.
If you want to see all three in their glory, you can find them at the Crawford Auto-Aviation Museum in Cleveland, OH.By the 1950s mainstream car manufacturers were dabbling with stainless steel, making small car parts such as hubcaps. GM went one step further in 1958 with the Cadillac Eldorado Brougham which featured a stainless steel roof.
They did the same to the 1979 Cadillac Eldorado Biarritz. The European car Maserati made their 1971 Bora with a stainless steel roof along with stainless steel windscreen pillars. But each part was a simple shape, to make production easier.
It would take a maverick car company executive to build a whole car from stainless steel. And that person was John DeLorean. A young high-flying GM vice president who one day quit his job to start his own car company.
He decided his first, and only, car, the DMC DeLorean would be brushed stainless steel. The DeLorean Motor Company was probably the only car company without a paint shop!
Only three cars sold to customers would be anything other than plain brushed stainless steel, and those were plated with 24-carat gold!
Yes, a company mad enough to put gull-wing doors on a car decided it would be a good idea to make a car that was covered entirely in real gold!
The car’s finish looked a little rough up close. But it had the advantage that small scratches could be taken out with a non-metallic scouring pad. Never worry about getting your car “keyed” ever again!
However, some customers didn’t like the unfinished stainless steel look, so took their cars to a paint shop to get the color they wanted. GMC had a brief and turbulent history, ending in receivership and bankruptcy in 1982. Great Scott!
The fabled Gold Plated, Stainless Steel Delorean carBut stainless steel cars had several disadvantages that have kept them from wider adoption:
It seems silly to put this as a disadvantage, but to car companies who’ve built their entire business around selling you a new car every five years or so, having a car that doesn’t decay isn’t that great.
There are also Government incentives that encourage customers back to car dealers every few years. With tight profit margins, many car companies rely on things like leasing agreements to stay in business, and changing that may cause the business unforeseen financial problems.
Stainless steel is more expensive than regular steel, and when margins are so tight, why add extra cost to the vehicle?
As we talked about before, stainless steel is a harder metal, which makes it harder to form the final shape for the car. It’s also more difficult to weld.
With a steel car, if there’s a dent you can use filler and paint to hide the problem With stainless steel, especially unpainted stainless steel, the only option is to try to restore it to its original shape, which is hard enough with regular steel, but harder with tougher stainless steel.
Most stainless steel cars produced weren’t painted at all, because let’s face it, they didn’t need to be. But to many people, choosing the color of their car is a big part of the process. There’s a good reason why Fords come in more than black these days!
And if you’re going to paint the car, then the car looks no more different from normal car bodies that were becoming much more rust-resistant by the late 1970s. People don’t want to stand out, but they want to be individualistic, at least in a more subtle way.
Car companies did this by first getting better at rustproofing. Then they started galvanizing the metal, and companies like Audi started making their bodies from aluminum which doesn’t rust anyway, and it’s softer than steel so easier to form.
Aluminum welding is trickier, but over time they’ve found ways to master it. So, this brings us to Tesla’s Cybertruck. They’ve opted to go for an even harder form of stainless steel – a grade they’ll use on the SpaceX Starship – so let’s see how those same disadvantages stack up.
Tesla isn’t as affected by making a car that will last more than five years before needing to be replaced. As we mentioned before, steel car bodies don’t rust like they used to, and the other components of a Tesla look like they’ll last ten years or more. Tesla’s a company in expansion, so it’s less reliant on repeat business from its customers.
This will still impact Tesla, but they’ll use less metal as the stainless steel body will be used as a stressed member to make the car more rigid. And with a starting price of $40,000, it seems the added cost of stainless steel isn’t going to impact the final car price very much.
There’s a good reason the Cybertruck is all angles. Instead of bending the metal, it’s simply cut out and welded together. Tesla and SpaceX are learning to weld this material on an industrial scale, and like Audi with aluminum, they believe that they can solve the problem.
This one may be harder to solve. Tesla’s claiming the Cybertruck can withstand some major impacts, so maybe fender benders just won’t be a big issue. But larger repairs could be a major expense, and repair shops will need to learn a whole new set of skills.
That very strength could be an issue when the car’s released. Elon stated in the Cybertruck reveal that the body “is literally bulletproof to a nine-millimeter handgun”.
It’s likely that we start to see more exotic materials come into the mainstream, there are various alloys out there plus there’s carbon fiber, it’s been around for close to 60 years and there’s still no way to mass-produce the stuff for cars. But that could change soon.