Characteristics of Hadfield steel: composition, application

The metallurgical industry is one of the most important components of the GDP of each country, and it also produces unique and useful materials. Without manu- facturing products, humanity could not do without. Steel is one of them. There are different types of this material that are used in many industries. Steel, which has a high plasticity and degree of wear, it is also Hadfield's steel, is a unique alloy. Requirements for it are regulated by GOST 977-88 and foreign analogs (USA, England, Germany, China, Japan, Finland, Spain, Korea).

History of Hadfield's Steel

Based on the name, it can be argued that it was Robert Hadfield who received this alloy. Who was this developer? Robert Gadfield is an English metallurgist who received an alloy with increased strength in 1882. Quite quickly this steel became widespread and turned out to be a very unique material.

After Hadfield developed a unique steel, the military became interested in its development. This is not surprising, since such an alloy is an integral component for the creation of protective equipment for the military.

Infantry helmets of increased strength - the first protective equipment, which is based on Hadfield's steel. Such helmets were used by soldiers of the British army, then the US military was interested in developing and started their production. Until the 80's the technology of Hadfield's steel did not change. But since the 80s an organoplastic was developed, which was not inferior in strength to the material developed by the British metallurgist, but it was much easier.

Helmets for infantry are not the only application of Hadfield's steel. The British company Vickers was the first to use this high-quality steel for other purposes. The caterpillar tank track was started from the Hadfield alloy in the 1920s. Steel increased the range of tank trucks from 500 to 4,800 kilometers. During the First World War, this increase in mileage was almost a miracle. Steel Hadfield became indispensable for tank building. Soon this alloy was used not only in tank building, but also in other industries. In the USSR, Hadfield's steel began to melt in 1936.

Hadfield steel: composition

Analyzing the chemical composition, in particular the percentage of carbon and manganese, you can see that this is austenitic steel. This structure increases wear resistance and strengthens the alloy. Thus, steel is resistant to deformation processes, having a high degree of plasticity and toughness. Metallurgists claim that this alloy was the first alloy steel, which began to be mass produced.

Properties of Hadfield Steel

Due to its properties, austenitic steel could not be treated with cutting tools, since it has a high viscosity. For the manufacture of products from this material, only casting can come up.

The Hadfield alloy has a high ability to hard work, which is significantly higher than that of similar steel alloys. Austenitic steel has a low hardness, but also high wear resistance at impacts, high pressure and at temperature differences. Based on these characteristics, we can say that the steel of a British metallurgist is suitable for work in aggressive environments.

Features of the welding technology of Hadfield's steel

The thermal conductivity of austenite is significantly lower than that of other steels, 4-6 times. The coefficient of thermal expansion is several times greater than that of low-carbon steels - 1.9 times. These are very important characteristics of the metal, since it affects the possibility of cold cracks in the temperature range.

There is a significant likelihood and hot cracks, which is due to the foundry shrinkage of the alloy, which is 1.6 times larger than the low-carbon metal. A high temperature transforms the austenitic structure into a martensitic structure, which increases the risk of cracking in the region of exposure to high temperatures.

Spheres of application of Hadfield's steel

Due to its chemical composition, characteristics and characteristics, austenite is used in many industries. Using steel products, you can be sure of their reliability and highest strength.

Wear-resistant steel is a fairly popular material. A huge number of industrial enterprises that produce high-strength products use Hadfield's steel. The following products are made from this alloy:

• Machine-building production.
• Tracks of caterpillar tanks.
• Tractors.
• Railway crossings.
• Turnouts, capable of working in severe impact loads and abrasion conditions.
• Prison bars on the windows.
• Components of crushers.

It is interesting to produce prison grills from austenite. Many believe that this is a form of mockery of prisoners who are attempting to escape. According to the classics of the genre, many relatives carry hacksaws for prisoners who, in the hope of freedom, begin to cut the window grilles.

In the case of using conventional metal, there is a possibility of escape. But Hadfield's alloy is a wear-resistant steel, which can not be sawed with an ordinary hacksaw. If we begin to saw the grids from the Hadfield alloy, then the work hardening begins, which entails hardening of the austenite. Hacksaw increases the hardness of the grate to hardness of the hacksaw and higher. Therefore, we can talk about the unreality of escape.

Steel 110G13L

The steel grade 110G13L is alloyed, which is used for castings and has special properties. This steel has a high wear resistance for impacts or pressure drops.

Application of the steel grade 110Г13Л

This brand was used in the manufacture of the following materials:

• Heavily loaded parts, which must be abrasion-resistant.
• Cone crusher.
• Teeth, walls of excavators.
• The body of ball, vortex mills.

Steel grade analogues

Such a steel is produced by many countries.

Properties of the steel grade 110Г13Л

Technological and mechanical properties of the material are given in the tables.

Mechanical properties at Т = 20 о С of the steel grade 110Г13Л

Heat treatment

The thermal treatment of Hadfield's steel directly depends on the level of carbon in the alloy. The higher the level of carbon, the higher the temperature. For example, if in an alloy it is at a level of 1%, then the temperature should be at least 900 degrees. If the carbon is 1.5%, then processing is possible at 1000 degrees. If the alloy is at the level of 1.6% in the alloy, then the temperature should be above 1050 degrees. Then, cooling with water follows.

A high temperature is necessary for the complete dissolution of carbides, which impair the quality of the casting, and for the growth of austenite grains. The life of the casting depends on its thickness. So, a thickness of 30 millimeters requires an exposure of 4 hours, and 125 millimeters - in 24 hours.

The wear resistance of Hadfield steel in the cast state is the same as after quenching. The austenite structure is surrounded by a carbide net and behaves under wear conditions in the same way as a uniform hardened alloy. That is why it can be argued that cast austenite in some microvolumes has the same viscosity and wear resistance as hardened steel. Its increased brittleness is explained by the influence of a carbide net, which causes a strong concentration of internal stresses.

Hadfield's steel was developed several decades ago. Today, alloy steel is an integral part of the production of many products in various industries. Without it, such industries as machine building, oil and gas, chemical, food, energy industries could not function properly. Do not forget about the construction, tank building and the development of new weapons that use the new achievements of the metallurgical industry. However, engineers and metallurgists do not fully understand all the properties, characteristics and characteristics of alloy steels.