Forged wheels. How stamped (steel) wheels are made

How are they made? And why are they so common in our country. I thought, “why not”, I’ll write an article, plus there will be a detailed video of the manufacturing process. It will be interesting, so read on...

Stamped wheels are indeed the most popular type now, because they are installed on budget trim levels of almost all cars. They also cover almost 90% of the market commercial vehicles, that is, they are installed on trucks, large or small buses, etc.

Why are they so popular?

So what explains this demand? It's simple - THIS IS THE PRICE, they are the cheapest of all types of wheels for cars, if you compare them with forged or cast ones, the price will be 2 to 5 times lower. That’s why they are so widely installed on budget car models.

They are also quite durable and elastic. If a cast or forged disk, under heavy loads (heavy weight in the car body or flew into deep hole), they can simply break, which is very dangerous at speed. Then this disc will simply get dented and then it can be restored relatively easily, we just “roll” it in a tire shop and ride on.

Of course, they do not have beauty, I would even say on the contrary, they are not beautiful at all. But let's say on a truck or a large bus, there is no time for beauty.

What are they made from?

The main material is a special elastic but strong steel. However, no one can tell you for sure; every manufacturer keeps the grades of steel or their mixtures secret.

As I wrote above, the big advantages are that this steel is a relatively elastic material. But the disadvantages are also obvious here:

She's rusting
It is heavier than cast or forged alloy wheels
Less susceptible to balancing
Not aesthetic appearance

Actually, these are all the disadvantages, but the main ones, in my opinion, are rust and weight.

How is it made?

Now the production process is automated to the maximum, because of this the cost is not so high.

A stamped disk is made from two main blanks - a “plate” and a “rim” (some call it a “cylinder”).

The “plate” is made of a round sheet of steel; stiffening ribs and holes are pressed into it using a special press, which serve to cool the disk. Next, holes are drilled for bolts or studs, and all excess is cut off from the disc rim. It is worth noting that the plate is almost never made flat, it is always made using stiffening ribs, so the weight withstand and the margin of safety are much higher.

Rim (or cylinder) - made from a flat and long sheet of steel. It is cut to size and bent into a circle using special shafts. Then the joint is welded and cut off weld in such a way that there is no roughness, that is, the rim is smooth on all sides.

After this, the already welded cylinder falls under the press, where it is compressed and it practically takes the desired shape. In general, there can be up to three or four presses, each giving the necessary bends and shapes. After this, all unnecessary protruding parts are cut off and the rim is sanded.

Then the main stage is connecting the “plate” and “rim”. The plate is placed inside and the cylinder is heated with a burner from the outside, after which it “falls” into special place fastenings

To fix it, the plate and rim are welded with a torch, then the seam is processed, thus obtaining an almost finished product.

All that remains is to drill holes for the nipple and paint the disc with special corrosion-resistant paint.

This is actually the entire manufacturing process.

Now we are watching a short video.

I’ll finish this, I think it was useful. Read our AUTOBLOG

The number of forged wheel manufacturers is not that large. Literally all forged wheels are quite expensive. And the cost of some exclusive discs differs tenfold from the cost of discs for ordinary consumption. All this is due to the expensive technology used to produce forged wheels. And not all companies consider it economically feasible to produce forged wheels.

There are several well-known companies, both domestic and foreign, that produce forged wheels. Moreover, they not only produce them, but also often develop exclusive models. And such exclusive discs have their own designers. And the disks not only differ in design, but have certain specifications, which will ideally fit a particular suspension of a particular car.

Here is a list of companies that make forged wheels, both in our country and abroad:

Slik;
VSMPO;
SMK (Aviation Technologies);
KraMZ;
BKMPO;
Beneventi;
Rocksroad;
Solomon Alsberg;
AGForged.

Moreover, what is interesting is that all foreign manufacturers of forged wheels developed as manufacturers of various components for cars. Those. this process was completely natural. But domestic manufacturers used technologies that were characteristic of the military-industrial complex (military-industrial complex). Namely, it was in these industries that all advanced technologies were most developed. And then these technologies, where possible, flowed into ordinary peaceful industry.

Forged rim wheels

There is a special category of disks that, with a very big stretch, can be considered forged. Such discs are produced only abroad and domestic manufacturers do not produce just such discs. The essence of such discs is that they only have a reinforced rim. The disc is produced using conventional casting technology, and then it is sent to a line where the surface of the rim is hardened by pressure. Hardening occurs due to compression of metal grains.

Formally, it turns out that the forging procedure seems to exist. But only one part of the disk is forged, and the rest, relatively speaking, remains raw. Therefore, such wheels cannot be considered forged. Although some unscrupulous sellers try to present them as such.

Domestic manufacturers of forged wheels do not use this technology and produce only forged wheels, in the classical sense of the term.

How are forged wheels made?

Forged wheels are wheels that are hot stamped. The materials used for forged wheels are exactly the same as for cast wheels. And the initial operation of making a blank is very similar to the casting operation. And then the differences begin.

The workpiece arrives at automatic line, where it is hot stamped using presses. Moreover, pressing to the desired state does not occur in one operation. At the first stage, the lowest-power press is used. The next stage is when the workpiece falls under a press, which creates greater force. Next, another press with even greater effort. And so on.

Typically, the press cycle ends at the third press. But in some cases, both the fourth and fifth press can be used. For domestic producers It is typical to use three presses in one line with different power and pressure.

After this, the forged workpiece is subjected to two types of heat treatment: hardening and tempering or metal aging. Tempering is needed in order to relieve internal stresses inside the metal that appear as a result of pressure treatment and as a result heat treatment(hardening).

Next, the workpiece is processed on a milling machine. During this processing, the disc acquires its final appearance and shape. Next, the disc can be subjected to galvanic operations, for example, chrome plating or bluing.

We invite the reader to take a break from reading and watch a video about the production of forged wheels:

What is the difference between domestic forged wheels and imported analogues?

First of all, there is a difference in price. Domestic wheels are significantly cheaper than foreign-made forged wheels. But at the same time, they are in no way inferior to them in mechanical qualities. But we must admit that the lineup domestic disks are still limited. Imported forged wheels have a lot of design solutions that make the wheels completely unique. This trend is not observed in the domestic disc industry.

It’s been a while since we addressed the topic “Made in Tolyatti”. But the current reason is very significant. Today we will look at how forged wheels are made at the Tolyatti company Slik.
Why forging?

Strictly speaking, forged wheels are not exactly forged. “Forging” is a common name; we will use it for convenience in this material. Correctly, the method of their manufacture is called hot stamping in closed dies. The disks obtained by this method are made from aluminum alloy of group AB, but disks from magnesium alloys are also known. Magnesium disks are light, durable, but very susceptible to corrosion - if the paint and varnish coating is damaged, the disk is destroyed literally before our eyes. Aluminum, with almost the same advantages, resists corrosion much better than magnesium (AB group alloys have a low content of iron, copper and other impurities), they can be used without coating at all, and at the same time they are cheaper.

The strength of a forged disc is higher than that of a cast one. The point here is both in the material and in the manufacturing method itself: during forging (hot stamping), the grains in the alloy structure are deformed, crushed and stretched in a certain direction. This gives the alloy a fibrous structure, and the final product can be made more “openwork” and lighter without critical loss mechanical properties. Simple numbers: the wall thickness of a forged wheel is on average 20% less than that of a cast wheel.
So, strength with low weight. What is the result? Reducing unsprung wheel weights, improving vehicle handling and dynamics. And also - elasticity at moderate impact loads and plasticity at peak values: when the “casting” is already destroyed, the “forging” is just beginning to deform. It is this “indestructibility”, coupled with ease, that you pay for when you buy forged wheels. They cost significantly more than cast ones, and this, again, is due to technology: it implies a very low metal utilization rate, which is only 30-40% in best case scenario. The rest during the manufacturing process of the disk turns into chips and is sent for remelting.

Background

Russia is a unique country in the production of forged wheels, as in many other issues. In the rest of the world, “forging” is a very expensive technology, almost hi-tech. But in Russia, conditions have historically developed that allow this technology to be used not only by athletes and owners of supercars, but also by “mere mortals.”

The fact is that forged car wheels are distant relatives of aircraft chassis and tank rollers! At the end of the 80s, it turned out that so many aircraft and other serious equipment of the empire, lying on its side, were no longer needed, and many factories defense complex turned out to be out of work. The conversion led to the fact that they began to produce anything, even kitchen utensils. But the unique technologies available at these factories made it possible to establish commercial production of forged car wheels. The price of the final product was several times less than foreign analogues, and the quality is at least no worse. The pioneer in this business was the Moscow defense enterprise VILS. The speaking and prophetic name, consonant with the English “weels” (wheels), stands for “All-Russian Institute of Light Alloys”.
At VILS we have mastered both the production of workpieces and their processing. Thus, in 1991 the first forged wheels were born. Russian production. Within four years, several more enterprises managed to put the Soviet legacy into the right direction: the Stupinsky, Samara, Belokalitvinsky and Krasnoyarsk metallurgical plants began to produce automobile “forging”. The cornerstone of the production of forged wheels is a press that develops a force of at least 10,000 tons. That's a lot. The listed enterprises had such presses (and only them), and all other preparations for production were a matter of technology.

Where is this from in Togliatti?

Over its almost 20-year history, Slik has managed to cooperate with all of these metallurgical plants. But for 13 years now, the Krasnoyarsk Metallurgical Plant has been a constant partner of Tolyatti residents. This plant produces blanks, which generally come in two types: with a three-dimensional pattern obtained directly by hot stamping and the so-called “blind”, a smooth “pan”, which is subsequently milled to obtain a disk with the final design. Initially, Slik worked with both types of blanks, and soon they began to receive blanks from Krasnoyarsk, made according to their own drawings, initially incorporating the wheel design into the blank. Over time, advanced milling machining centers were added to universal milling machines, which now makes it possible to obtain a disk with an original design of any complexity from the initial “blind rat.” The design of the new slick wheels is carried out by the company's in-house design engineers.

And the topic of forged wheels appeared in our city thanks to motorsport. After all, it is unthinkable without light and durable wheels, and in Russia, strictly speaking, “forging” was first produced exclusively “for athletes.” A forged wheel with its almost limitless strength life is almost impossible to destroy: there are often cases when, at rally competitions, crews, having damaged a tire, ride on a bare wheel (!), thereby saving the result. Neither stamped steel nor light alloy cast wheels can do this, because in racing conditions, with a missing tire, they are destroyed instantly. In a word, it is not surprising that as soon as the forged wheel technology took off, Togliatti racing drivers became interested in its localization in their homeland.
The founders of the Slik company were guys from the AvtoVAZ rally team. Just a few names that will tell a lot to a motorsports fan - Semyon Barulin, Alexey Popov, Viktor Shkolny. Actually, this is why the Slik company still has close ties with the world of motorsport - its products can be seen on the vast majority of domestic racing cars in recent years.

So, on the initiative of racing drivers, this company, which has amazing production, appeared in Tolyatti and subsequently entered the mass market. It is stunning not in size or volume of production. First of all, something else is surprising: somewhere in the wilds of the northern side of AVTOVAZ they manufacture products of the highest world level for the general consumer and sell them at prices that are absolutely ridiculous for the world level. Now Slik products are developing in several directions at once: the number of design options is increasing, their shape is becoming more complex, and new standard sizes are appearing: 18, 19, 20, 22 inches... If you are not closely connected with this industry, you hardly know that every year Slik releases 3 or 4 new products! Yes, yes, in Togliatti, with a design that corresponds to global trends and with excellent quality.

The geography of supplies of branded discs from Tolyatti is truly immense - this is made possible by the online store operating on the company’s official website. A batch of Slik discs can be ordered in almost any corner of Russia. In addition, discs are available in stores of official dealers, of which there are now more than 15 throughout the country - from Vladivostok to Belgorod.

Process

In our story, we have already touched upon the technology for producing forged wheels. And broadly speaking, it can be divided into two stages. First: obtaining a workpiece (the so-called “pan”) from an aluminum alloy. First, at the Krasnoyarsk Metallurgical Plant, an aluminum column comes out of a huge vertical furnace - a rod with a diameter of 180-250 millimeters and a length of about 6 meters. Needless to say, this is a normal “rod”...

The rod undergoes homogenization and is cut into “ingots”. Next you need to get a blank from it. Note that aluminum alloy of group AB cannot be cast in ready-made form, but it is perfectly susceptible to plastic deformation at elevated temperatures (about 700 degrees Celsius), and this is exactly what is needed.

An aluminum “ingot” of cylindrical cross-section is driven through three presses, pressing with different forces, heating, cooling and heating again, successively bringing it closer to a shape that already resembles a wheel with a rim. Now the AB alloy workpiece can be subjected to hardening followed by aging to remove residual stresses and to make the disk more elastic and durable. At the end of these processes, the same “pan” is obtained that will end up in Tolyatti.

Well, the second part of the process, taking place in the workshops of the Tolyatti company Slik, is presented in photographs. A workpiece purchased in Krasnoyarsk undergoes turning, consisting of two or two or three stages - various surfaces of the future disk are sharpened. Then comes milling, that is, just obtaining the final design of the wheel. The mounting holes are drilled and the burrs are cleared. Then the surface of the disc is prepared for painting: degreasing, etching, brightening, washing and drying are carried out, sequentially immersing batches of discs in huge baths. Painting also occurs in three stages - priming with powder primers, coating with liquid metallic and, finally, liquid varnish.
The almost finished wheel comes with a plug and a “Slik” sticker. Packed in a bag and a branded box - and sent to the customer, official dealer or to a warehouse, from where it will reach the store and the buyer.

And one more interesting fact. The blank for a 15-inch wheel received from Krasnoyarsk weighs about 15 kilograms. And the weight of the finished wheel is only about 5-6 kilograms! 10 kilograms of expensive metal goes into shavings, which need to be melted down in order to be put back into production. We cannot even approximately estimate, for example, the loss of electricity in the process of obtaining a forged disk, but losses due to chips are perfectly illustrated by our photographs - after removing the disk from milling machine a gigantic “cake” remains underneath... Isn’t it true, now it becomes clear why a forged wheel is somewhat more expensive than a cast one?

Let's just say that a forged wheel is for those who understand. For a non-mass, demanding client. Sometimes this is even piece production - the Slik company works from an order for four wheels. In principle, you can get absolutely unique forged wheels that only fit on your car.

1. Preparing wheels for painting.

2, 3. Already painted wheels

Forging or casting?

Perhaps this is one of the most interesting questions for the consumer: is it possible to distinguish by appearance whether this is “forging” or “casting”? In theory, it's simple: a forged wheel typically has flatter surfaces that don't have large roundings. But you can also make a cast disc this way. On the other hand, a forged wheel can have an advanced design with many grooves, complex grooves and roundings. Therefore, simply appearance is a weak distinguishing factor.

There is another way - the weight of the wheel. A forged wheel is often as much as a quarter lighter than a cast wheel of the same size. In absolute values, the following is obtained: if a 15-inch “forging” weighs about 6 kilograms, then the same cast disc will already weigh 7-8 kilograms. Perhaps, without a certain skill, it is difficult to catch such a difference (although the spread between “casting” and “forging” can be up to 5 kilograms, if it is a large standard size), but it is even more difficult to calculate “forging”, for example, by the sound of tapping on a disk - Only a pro can do this. But there is another option - there is, so to speak, the other side of the coin.

The back surface - the one that is adjacent to the hub - is not the same for forged and cast wheels. On a cast disk, it usually has a complex relief, with many indentations. Thus, on a cast disk, even at the stage of obtaining the workpiece, they strive to reduce weight. While the “wrong side” of a forged disc is always simple, consisting of flat surfaces. As we already know, the low weight of the wheel is achieved in the case of “forging” using completely different methods. But in general, the “wrong side” of a cast disk can be made smooth and flat. Therefore, the 100% way to identify a branded forged wheel is marking. Below is a story about her.

Beware of fakes!

Needless to say, the Tolyatti company Slik is the most authoritative manufacturer of forged wheels in Russia and, of course, deserves to be included in our “Made in Tolyatti” section. Slik is closely associated with motorsports, supplying its products to a wide variety of domestic racing series, and the average consumer throughout Russia has long appreciated the benefits of these forged wheels. We are proud that such a company is located in our city.

And now - extremely important information. The reader must remember: Slik branded wheels are “forging”, and only that. Therefore, if you are offered a suspiciously cheap product with a Slik sticker on the iron market, you are probably looking at a cast counterfeit of a famous brand.

All disks produced in accordance with the requirements of the standard are marked. Inside the rim, the wheel size, wheel mount, offset size, manufacturer, production date, and the sign of the PCT standardization body are indicated. The correct disk has a stamp on the inside containing all this information, and the stamp itself is under the varnish and therefore cannot be damaged. All Slik wheels are certified and tested on stands.
If you think about it, the price for the quality and excellent properties of the original Slik disk is not so high: in a company store a 14-inch disk costs about 3,500 rubles. There really is a point in going there to get new tires - here you definitely won’t get “leftist”, they will unobtrusively and reasonably select best option, they will equip your car with it, and while this is happening, you will be treated to coffee. The store address can be found at

Without this seemingly ordinary part, not a single car will be able to drive. A wheel for any car can be compared to shoes for a person. We always try to make sure that our shoes are comfortable and beautiful, but doing the same with rims is quite difficult. Incorrectly selected boots can threaten us with minor troubles; at the most, incorrectly selected discs can threaten life.

There are three types of car wheels: stamped, cast and forged..

Stamped ones are most often made of steel, while casting and forging are performed mainly from aluminum. Forged wheels best meet the requirements of safety, reliability and visual appeal. True, their cost is more expensive than all other types of rims.

Forged wheels are made from aluminum smelted from alumina, which in turn is obtained from aluminum ore bauxite. The mined red clay (bauxite) is sent to alumina refineries, where alumina is separated from it, separating various impurities and producing a white powder (aluminum hydroxide). The resulting powder is then sent to aluminum smelters. The most large plant aluminum production is located in the Republic of Khakassia.
At the plant, the desired metal is separated from aluminum hydroxide by hydrolysis. The aluminum production workshop consists of several hundred baths sequentially connected to each other in a multi-kilometer chain. The hydrolysis process occurs with enormous energy consumption (several gigawatts per hour), so large that in order to provide it with the necessary amount of energy, it requires its own power plant and not just a power plant, but such as the Sayano-Shushenskaya hydroelectric power station, which was built specifically to provide energy aluminum production. In this regard, it becomes clear why raw materials for aluminum production are transported so far across half the country, specifically to the plant in Khakassia.

The separated metal is then sent for maturation to gas furnaces, in which it is placed along with alloying elements (such as iron, titanium). Iron is added to aluminum to give it greater strength, and titanium for ductility. As a result, mature “modified” aluminum is already coming out of the gas furnace. Then samples must be taken finished product for check chemical composition. Then, if the test is successful, the aluminum is poured into special molds and cooled in them.

The cooled aluminum is sent to disc production plant, there it is again melted in a hot furnace, where other elements are also added to obtain the alloy that will ultimately make up the disk: magnesium, manganese and a little copper. During the mixing process, unnecessary impurities are slagged off, and the pure alloy is sent to a billet casting machine, in which six-meter aluminum pillars are first made, then they are cut into individual small pieces. Then the alloy is again checked for compliance with the standard.

At the next stage of production, the blanks are stamped; this process involves squeezing under pressure the blanks obtained at the previous stage, which, as a result of squeezing, acquire amazing strength and have the shape of pancakes. Then, under the influence of a press, so-called pans are obtained from the pancakes, which are heated to a certain temperature and sent under the next press, where wheel blanks are obtained. They are hardened: heated to 550 degrees and abruptly placed in cold water, this is done 3 times. After such hardening, the metal becomes fine-grained, and therefore very durable.

At the final stage, the discs are machined, after which they acquire their final presentation. First, the designer draws the appearance of the disk, the drawing is transferred to a special program, with the help of which the machine’s computer refines the disk to the desired appearance.
In the process of giving the disk the desired look, a lot of aluminum shavings are produced, which is waste. This is why the price of a forged wheel is high.
Then 1 disc is removed from each batch for very strict control. If the selected sample does not pass the control, then the entire batch is rejected.