Hardox steel: features, characteristics, advantages of use

For more than seven years, the Artmash plant has been using Swedish sheet steel Hardox 500 in the manufacture of its own equipment. This material was chosen as the most wear-resistant and durable material, taking into account the specifics of the operation of our shredders and other products. How does Hardox 500 differ from other abrasion-resistant steels on the market?

Summary of the article

To get started, we recommend watching a video of testing a body made of Hardox steel. In addition to abrasion resistance, which is important for us, the ability to recover from deformation, impact resistance, resistance to vibration destruction, compressive strength and other parameters were tested here.

SSAB began producing Hardox wear resistant steel products in 1983. For the past 38 years, the company's technologists have been constantly working to improve the product, thanks to which it surpasses its counterparts in terms of the combination of hardness and ductility. Manufacturing facilities are located in Sweden, Finland and the United States. Therefore, we, as consumers, can not be afraid of the deterioration in quality, which is observed when transferring production to third world countries.

Today, sheets with a thickness of 0.7 mm to 16 cm are available on the market. All of them are easily recognizable by the traditional red anticorrosive primer and the HARDOX in my body mark.

Research has shown that 6.5 mm Hardox sheet has the same service life as common structural steel with 80 mm sheet thickness. The checks were carried out under the same wear conditions. The use of HARDOX steel allows you to reduce the thickness of the metal used by more than 12 times!

The service life of Hardox products is twice as long as that of similar products from other grades of steel with the same hardness. This means that the user does not have to spend time and money on frequent replacement of worn-out consumables or repair of parts.

Mechanical properties of Hardox steel

We are confident in the durability of this material, as it is hardened throughout its entire thickness. At the same time, in the central region, the hardness is reduced by no more than 10% in comparison with the surface one.

Brinell hardness (HBW) is tested in SSAB laboratories in accordance with EN ISO 6506-1. The control is carried out at least once per 40 tons of products.

Hardox sheet steel has a hardness of 450-540 HBW Brinell, which corresponds to 47-54 HRC Rockwell. For comparison, bearing hardness starts at 55 HRC.

One of the verification stages is demonstrated in the video.

SSAB also carefully controls sheet thickness, length and width. They always comply with the requirements of the standards EN 10 029 for class A (flat products) and EN 10 051 (for coils).

The flatness of wide class D sheets even exceeds the requirements of EN 10 029. The flatness of coils is controlled according to class A, which is more stringent than the standard EN 10 051.

No less attention is paid to the surface quality of the sheets. They are guaranteed to meet the requirements of EN 10 163-2 for class A, subclass 1.

When using Hardox steel for the manufacture of shredder hoppers, bending properties are also important to us. The manufacturer guarantees that they meet the G-class for wide sheets and the C-class for rolls. Practice has proven that the material does not lose flexibility even at low temperatures, therefore it retains its integrity and appearance in the event of a fall or impact.

Chemical composition of Hardox steel

SSAB says the secret to their steel's reliability lies in the correct chemistry and high water pressure. The table shows the percentage of elements used. The manufacturer emphasizes that this steel has a fairly simple chemical composition.

Hardox 500 steel has a fine grain structure. The table shows the maximum possible percentage of each element. Carbon, Silicium, Mangan, Chromium, Nichol, Molybdenum and Boron are alloying additives.

Based on the components used, the carbon equivalent is calculated. The table shows the limit and average values ​​for different sheet thicknesses.

Due to all the described chemical and mechanical properties, Hardox steel is very workable. Therefore, parts of complex shapes can be welded from it in strict accordance with the drawing. Finished parts look better, last longer and mate properly with other structural elements.

Mechanical testing of Hardox steel

To control the quality of rolled metal at SSAB factories, random samples are constantly tested for compliance with standards in such parameters as:

• Stretching (ISO 6892-1).
• Stretching in thickness (EN 10 164).
• Strength (EN ISO 6506-1, 6508-1, 10 083).
• Impact strength (ISO 148-1).

The video demonstrates tensile tests. As you can see, tremendous forces are required to break, which are not generated under standard operating conditions.

Tests and calculations show that under a constant friction load against granite, Hardox steel products serve 30-50% longer than abrasion-resistant steels of other grades and 85-100% longer than other common steels. The comparison was carried out with materials with a similar Brinell hardness - 400 units. Tests for resistance to abrasion with coal, iron ore, sand, glass, debris with metal impurities and other abrasives also demonstrated a significant advantage of Hardox steel.

Other Methods for Testing Hardox Steel

To check steel for cracks, irregularities and impurities, ultrasonic flaw detection is carried out at SSAB factories with a thickness of 6 mm or more. Typically, metal is allowed for sale that meets the EN 10 160 standard in class E1 and S1 (if the thickness is more than 10 cm). By agreement with the client, the plant also produces steel, the parameters of which are brought to other standards: SEL 072, ASTM 435, EN 10 160, ASTM 578 ...

When purchasing Ukrainian-made metal, from time to time we encounter manifestations of hidden cracks or inclusions both during the processing of blanks at the factory and after the sale of the finished product. In such cases, we will replace the defective part at our own expense.

Buying Hardox steel, we can be sure that we will not incur losses due to metal defects and will not cause trouble for our customers.

Application of Hardox steel

Due to its high abrasion resistance, Hardox steel is often used for the manufacture of:

At the Artmash plant, the Hardox 500 steel is used for the production of hammers and rotors of crushers, and, at the request of the client, for bins and cyclones of other equipment.

It is important for the end user that Hardox makes it possible to:

To date, there is no steel on the market that would have comparable abrasion resistance (would withstand constant abrasion by abrasives), would not crack from strong impacts in the cold and would provide a similar service life of products. That is why Hardox 500 is used at the Artmash plant.