45 steel (quenched and tempered after forging) non-metallic inclusions

45 Steel (Post Forging Heat Treatment) Nonmetallic Inclusions

Nonmetallic inclusions are small particles that are insoluble in molten steel. They are divided into two categories: organic nonmetallic inclusions and inorganic nonmetallic inclusions. Nonmetallic inclusions are composed of Cr, C, Al, Si, O,Mn and other elements in different combinations. They can interfere with the normal operations of steel plants and precision steel parts manufacturing.

45 steel is high quality, low carbon quenched and tempered steel plate. During heat treatment, nonmetallic inclusions cannot be completely removed and need to be monitored to ensure quality. Many alloying elements need to be added to steel. The microstructure of 45 steel can be effectively modified and improved after forging, hot rolling, annealing and other heat treatments. During these processes, nonmetallic inclusions are produced, which increases the difficulty of the control of steel quality.

In order to reduce the influence of nonmetallic inclusions, the control of heat treatment technology and the selection of slag system are the key measures. When 45 steel is heated to a certain temperature, it will be quenched and tempered to achieve the desired mechanical properties. During this process, the nonmetallic inclusions must be strictly controlled to avoid negative effects.

At the same time, it is also important to optimize the slag system. A slag system with low melting point and low viscosity should be selected to aim at reducing the degree of adsorption of nonmetallic inclusions in the slag, and secondary inclusions caused by the re-dissolution of nonmetallic inclusions.

In addition, the refining process can also be used to reduce the amount of nonmetallic inclusions. It can be carried out by spheroidizing annealing, controlled rolling or controlled cooling. However, the refining must be carried out according to the requirement of specific steel grades so as to obtain better mechanical properties.

In summary, the control of nonmetallic inclusions in 45 steel is of great importance to ensure the quality of steel and ensure the accuracy of the production process. A comprehensive optimization strategy should be adopted, and the selection of heat treatment technology, the optimization of the slag system and the refining process should be combined to effectively control the quality of 45 steel.

20Mn45 steel is a kind of steel with a carbon content of 0.20%, a manganese content of 0.60-1.00%, and a silicon content of 0.90%. It is a kind of manganese-silicon alloy steel. Its mechanical properties of 20Mn45 steel after quenching and tempering treatment, the tensile strength (σb) of the steel is 630-850 MPa, the yield strength (σs) is not less than 375 MPa, the elongation (δ5) is not less than 10%, the a reduction of area is not less than 5%, and the impact energy (Akv) is 28-45 Joule.

20Mn45 steel is widely used for manufacturing mechanical parts, forgings and other components which are axial static load and moderate impact load, and can also be used to manufacture parts which bear certain plasticity at the room temperature. Besides, it can also be used to manufacture cold work plastic die steel.

For the production of 20Mn45 steel, one-time deformation is adopted in the production process. It is mainly used to obtain difficult-processing steel and improve the cracking sensitivity of the surrounding area of weld seam. Furthermore, the 20Mn45 steel is subjected to the post-forging annealing process to reduce the hardness of the steel, insert the toughening element, eliminate the harmful elements in the steel, get rid of the residual stress, so that the steel has high plasticity and toughness.

In summary, 20Mn45 steel is a kind of manganese-silicon alloy steel, with a carbon content of 0.20%, a manganese content of 0.60-1.00%, and a silicon content of 0.90%. Its mechanical properties of 20Mn45 steel after quenching and tempering treatment, the tensile strength (σb) of the steel is 630-850 MPa, the yield strength (σs) is not less than 375 MPa, the elongation (δ5) is not less than 10%, the a reduction of area is not less than 5%, and the impact energy (Akv) is 28-45 Joule. Moreover, it is mainly used to manufacture mechanical parts, forgings, cold work plastic die steel and so on.