The characteristics of U8 steel, as well as other grades of tool type, are due to the fact that such a substance as carbon is in the composition. The main difference between this material and other alloys is that parameters such as wear resistance, strength and hardness are at a higher level.
Material marking
Before proceeding to consider the marking of steel U8, it is worth noting that in each state its own standards and the same material can be designated in different ways. As for the Russian Federation, then the GOST indicates the marking precisely U8. It is also worth noting that there is a slightly modified composition, which is designated as U8A.
- The first thing that goes in the description is the letter "U". It only indicates that steel belongs to the tool class. It does not indicate the content of any substance or component.
- The number, in this case 8, will indicate the concentration of the main substance in this class of steel. The main substance is carbon, and its content is indicated in tenths of a percent. That is, in U8 steel, the carbon content is 0.8%. Neither more nor less.
- As for the modified type of steel U8A, then everything is quite simple. The presence of the letter “A” is only a general designation, which indicates that some harmful impurities were removed from the composition, which allowed to slightly improve the quality of the starting material.
Additions
It is important to add here that the marking is completely missing any other designations. However, the chemical composition of the steel provides for the presence of many other components. For example, this includes substances such as silicon and manganese. In addition, some harmful impurities are also present in the structure. Among them, one can distinguish, for example, phosphorus and sulfur, as the most common. Naturally, the quality of steel will directly depend on the concentration of these substances. The higher their content, the worse the performance of the material.
Brief description of the substance
The characteristics of steel U8, like U8A, are most suitable for making various tools from it. That is why it belongs to the group of instrumental. It should be noted right away that in the manufacture of this product, such a procedure as alloying is not carried out. The absence of this operation does not allow to improve the required parameters, for example, hardness or strength, but it does not increase the price of the material, which is very important.
Key product properties
Steel U8 has the following main parameters:
- As mentioned earlier - a high indicator of strength and hardness. This is necessary so that the manufactured tools can serve long enough without additional sharpening operations.
- Heat resistance. During any machining, friction occurs, due to which the temperature of the material rises. If too fast and / or too strong heating of the steel occurs, then this will lead to poor performance. A defect such as increased ductility and rearrangement of the crystal lattice will occur. Such a parameter as heat resistance determines the ability of the steel to undergo any mechanical stress and not heat up. If the material is still heated, then the steel will not lose its strength. As for steel U8, this indicator is not too high for her.
- Low susceptibility to sticking or welding. During processing, the feed rate, for example, can be quite high. This will lead to the fact that different metals will begin to interact with each other, and this, in turn, will cause adhesion. Naturally, the quality of such steel will ultimately be deteriorated.
- Another important parameter for U8 steel is resistance to cracking. Quite often, such a situation occurs that during mechanical processing the material is subjected to mechanical shock or strong vibration. If the stability is too low, this will cause the formation of microcracks in the structure of the material, which will lead to a significant increase in fragility.
- The last characteristic is the level of viscosity of the alloy. This parameter is very important for those steels from which objects will be made that are subject to future shock loads. Therefore, for tool alloys, this parameter is very important.
Material application
Most often, U8 steel according to GOST 2283-79 is used to obtain cutting surfaces of various tools. It should be noted that this material resists thermal stresses well. However, at the same time, it is still most often used for those elements that during operation will not be exposed to heat. Most often, steel is used to make a chisel, chisel, saw, ax, hammer, etc. In other words, we can say that the main use of steel of this brand is the production of metalwork and assembly tools.
Material Composition
As mentioned earlier, the composition includes not only carbon. Almost 97% is Fe. Then follows C - 0.76-0.83%. The content of a substance such as Si and Mn is 0.17-0.33%. In addition to these components, P, S, and Ni also enter the structure. The content of these substances is quite small and does not exceed 0.25%. Here you can add that the hardening of U8 steel is carried out at a temperature of about 780-800 degrees Celsius. For vacation, plain water is used. The tempering temperature of the metal is approximately 240-270 degrees Celsius. Time for vacation is allocated approximately 30-40 minutes.
Reviews about steel for the U8 knife are all quite positive. The owners claim that if the device is used correctly and does not expose it to too strong shock loads, then it is able to serve for a long time. Steel itself is quite sharp and, if you do not cut substances that are characterized by a very dense structure, then the sharpness will remain for a long time.