What are the mechanical properties of steel?What are the indicators of steel performance?

What are the mechanical properties of steel?

The properties of metal materials are generally divided into two categories: process performance and service performance.

Process performance refers to the mechanical properties of metal parts in the process of cold and hot processing. The processing capability of metal materials determines its adaptability in forming process. Because of the different processing conditions, the technological properties required are also different, such as casting properties, weldability, malleability, heat treatment performance, machinability, etc.

Service performance refers to the performance of metal materials under conditions of use, including mechanical properties, physical properties and chemical properties. The performance and service life of metal materials depend on its performance.

In the mechanical manufacturing industry, the general mechanical parts are used in the normal temperature, normal pressure and non strong corrosive medium, and in the process of use, the mechanical parts will bear different loads. The mechanical properties of metal materials under mechanical loads are called mechanical properties.

The mechanical properties of metallic materials are the main basis for designing and selecting parts. The mechanical properties of metal materials will be different depending on the load characteristics (such as tensile, compression, torsion, impact, cyclic load, etc.). Commonly used mechanical properties include strength, plasticity, hardness, impact toughness, multiple impact resistance and fatigue limit.

What are the indicators of steel performance?

1. Strength

Strength refers to the performance of metal materials under static loading to resist breakage (excessive plastic deformation or fracture). The strength of load is divided into tensile strength, compressive strength, bending strength, shear strength and so on, as the loading mode has the form of tensile, compression, bending and shearing. There is always a certain connection between various intensities. Generally speaking, tensile strength is used as the basic strength indicator.

2. Plasticity

The metal material has the ability to have permanent deformation without producing defects under the load. The plastic deformation occurs when the stress of the metal material exceeds the elastic limit and after the load is removed, the material is deformed when a part or full load is retained.

3. HardnessDo you know what the metal hardness is.pdf

Hardness is a pointer to the hardness of a metal material. At present, the most commonly used method of measuring hardness is the pressure entry hardness method. It is pressed into the surface of the metal material under a certain load with a certain geometry, and the hardness value of the material is measured according to the degree of pressure.

The usual methods are Brinell hardness (HB), Rockwell hardness (HRA, HRB, HRC) and Vivtorinox hardness (HV).

4. Fatigue

The strength, plasticity and hardness discussed above are the mechanical properties of metal under static loading. In fact, many machine parts work under cyclic loading. Under this condition, parts will produce fatigue.

5. Impact toughness

Metal materials resist the impact of the impact load and not to be destroyed. Toughness refers to the metal material under the action of tensile stress, before the fracture has a certain plastic deformation characteristics. Gold, aluminum and copper are tough materials. They are easily drawn into wires.

Why is the mechanical properties of the forgings often superior to the castings?

Because the compactness of the forgings is better than that of the castings.

The forgings are cast blank by repeated rolling, the density is high, the shrinkage cavity and shrinkage are rolled, and the columnar dendrites are broken, and the mechanical properties are eliminated.The casting is a product formed by molten metal pouring into the mold after solidification. The tissue is large, and the interior is pinky.

Therefore, the mechanical properties of the forgings are better than those of the castings.