20CrNi2Mo (diameter 6mm round steel) (hot rolled) low-magnification structure and non-metallic inclusions

Introduction

20CrNi2Mo (diameter 6mm round steel) (hot rolling) is a low-alloy steel which is widely applied in the field of vehicle, shipbuilding, and other structural parts. It has good plasticity and weldability, high strength, and good corrosive resistance. The alloy steel is also suitable for medium and low temperature tempering and has the features of strong resistance to impact, fatigue strength, and good hardenability.

Chemical Composition

20CrNi2Mo (diameter 6mm round steel) (hot rolling) is a low-alloy steel containing chromium, nickel, and molybdenum. It is composed of the following elements:

C: 0.17-0.24%, Si: 0.17-0.37%, Mn: 0.60-0.90%, Cr: 0.70-1.20%, Ni: 0.85-1.20%, Mo: 0.15-0.30%, P: 0.040%, S: 0.040%.

Heat Treatment

20CrNi2Mo (diameter 6mm round steel) (hot rolling) is heat treated primarily for the purpose of setting the materials mechanical properties and microstructure. The alloy steel can be subjected to a quenching process, which involves heating the material to a certain temperature and subsequently cooling it quickly by immersing it in water or oil. This process will give 20CrNi2Mo a strength, hardness, and wear resistance.

Non-Metallic Inclusions

A significant feature of 20CrNi2Mo (diameter 6mm round steel) (hot rolling) is non-metallic inclusions. These non-metallic inclusions are components added to the alloy steel during the manufacturing process and are present in the materials microstructure. Non-metallic inclusions in 20CrNi2Mo can adversely affect the materials mechanical properties. The presence of non-metallic inclusions can limit the materials ductility, impact strength, and fatigue strength.

Low-Magnification Microstructures

The microstructure of 20CrNi2Mo (diameter 6mm round steel) (hot rolling) mainly consists of a variety of complex grains. Generally, the intergranular area is small, the micro-segregation is not obvious, and the morphology of the carbides is discrete. The carbides in 20CrNi2Mo (diameter 6mm round steel) (hot rolling) are mainly Ti(C,N), MC, M6C or M3C, etc., of which the TiC is in a spherical or elliptical shape.

Conclusion

In conclusion, 20CrNi2Mo (diameter 6mm round steel) (hot rolling) is a low-alloy steel with good plasticity, weldability, and strength. After heat treatment, it additionally gains hardness, wear resistance, and strength. The 20CrNi2Mo alloy steel contains non-metallic inclusions, which are components present during the manufacturing process and are present in the materials microstructure. Low-magnification microstructures of the material reveal a variety of complex grains and dispersed carbides such as Ti(C,N), MC, M6C or M3C, which mainly appear in a spherical or elliptical shape.

The 20CrNi2Mo steel (diameter 6mm round steel) hot rolled low magnifications and non-metallic inclusions are common components of the alloy. In general, the 20CrNi2Mo alloy contains a certain amount of C, Si, Mn, Cr, Ni and Mo, and some may contain other alloy elements, such as Nb, Ti, Al and V.

The 20CrNi2Mo steels hot rolled low magnifications are hypoeutectoid in nature, meaning they contain a high percentage of ferrite at lower temperatures. This stage of transformation makes the material hard, tough and ductile. In general, there is a decrease in ductility as the steel transitions in temperature, which is why higher temperatures cause the hardness and strength to increase.

The non-metallic inclusions present in the 20CrNi2Mo steel are normally silicates, alumina, and sulfides. Non-metallic inclusions serve two main purposes: increasing the strength of the steel, and reducing its ability to crack or fatigue. Non-metallic inclusions work like fibres within the lattice structure of the steel. These fibres act as obstacles for the movement of dislocation, preventing displacement and the formation of cracks. The presence of ceramic particles also provides selective abrasion and wear protection.

The magnitude and frequency of non-metallic particles in the 20CrNi2Mo steel can affect the fracture surface and strength. In higher magnifications, large, heavy particles can render the steel brittle and prone to fracture. Smaller and finer particles, however, can actually increase the strength by creating more obstacles for dislocation.

In conclusion, the 20CrNi2Mo steel hot rolled low magnifications and non-metallic inclusions are necessary components of the alloy. Low magnifications create a harder and tougher material while non-metallic particles provide the steel with strength and the ability to resist fatigue. When used appropriately, these mechanisms can ensure that the 20CrNi2Mo steel is suited for a variety of applications.