High strength steel

The use of high-strength quenched steel with a higher wear resistance to manufacture and repair steel structures and machine components has numerous advantages:

• Reduced weight of products and structures while maintaining strength characteristics

• Increased payload capacity

• Reduced cost of transportation, assembly and installation

• Reduced cost of repair and maintenance

• Combined wear, crack and deformation resistance

Given the aforementioned properties, high-strength steel delivered in a quenched and tempered condition is widely used in heavy engineering, construction and other industries. The manufacturing of heavy-duty above-ground, underground and lifting machinery accounts for more than 70% of quenched steel plate consumption.

High-strength steel allows for significantly longer service life of equipment and machines, less frequent replacement and repairs of machinery, and less downtime.

The advantages of thermomechanically rolled products come from their key properties, such as low carbon equivalent, high strength and high impact toughness. Compared with conventional steels, ТМСР rolled products demonstrate greater efficiency during processing: reduced costs for welding consumables, no need for preheating steel and additional heat treatment, reduced overall steel intensity of structures, and shorter project implementation time.

High-strength steel is used mainly in the construction and different engineering industries.

Using high-strength thermomechanically rolled steel instead of regular structural steel grades substantially reduces the steel intensity of civil structures due to the use of columns with thinner walls and flanges, yet the same compression strength performance. For example, the use of TMCP plates to make welded columns of modern commercial high-rise buildings enables 20-30% savings in rolled steel products. When used in open wagon structures, TMCP plates make them lighter (and increase their payload capacity correspondingly) by 30-35%.

High-strength steel delivered in a quenched and tempered condition is manufactured in accordance with the standards EN 10025-6, DSTU EN 10025-6, ASTM A514/А514М, ASTM A517/А517М, GOST 19281, etc, as well as manufacturers' internal regulations.

High-strength steel delivered in a thermomechanically rolled condition is manufactured in accordance with EN 10025-4, DSTU EN 10025-4 and EN 10149-2, as well as other regulatory documents and under own brands of manufacturers.

High-strength steel is manufactured in reversing mills by hot deformation of semi-finished steel products such as continuously cast or rolled slabs. Plates undergo strengthening treatment either in the final stages of rolling and cooling in the mill or by heat treatment offline.

Quenching is heating steel above the temperature of phase transformation with consequent quick cooling at a speed above the critical (in water, oil, polymer or ether mix, etc). A heating temperature and cooling medium are selected based on the chemical composition and required structural condition of steel. After quenching, steel acquires non-equilibrium metastable structure and has greater strength (up to 2,500 MPa), hardness (up to 600-650 Vickers), wear resistance and brittleness. Quenching can involve the dedicated heating of steel after rolling or the use of rolling heat (known as direct quenching).

The thermomechanical controlled process (rolling; TMCP) requires meticulous control of the plate temperature and deformation during rolling. Properties obtained after TMCP cannot be accomplished by normalising or other types of heat treatment. The final fine-grained microstructure of steel is obtained by micro-alloying, rolling in a certain temperature range and controlled cooling (as well as accelerated cooling using an air-water mix).

Due to their high strength, weldability and resistance to brittle cracking, TMCP steel products can be applied in structures with operating temperatures of up to -50 °C with guaranteed values of impact strength.
 

Buy high-strength steel from the manufacturer

Metinvest produces low-alloy and alloyed high-strength steel in accordance with the requirements of international standards and customers' specifications. The products can be delivered after special types of rolling (controlled, thermomechanical and normalised rolling) and heat treatment offline (quenching and tempering, normalising, etc). High-strength steel can be purchased through the global sales network of 38 sales offices in Europe, Asia, Africa and America, as well as 16 metal service centres in Ukraine, and authorised dealers.