Knowledge about the mechanical properties of steel channel iron

In recent years, the market demand for steel channel iron in my country has been increasing day by day, the scope of application has been expanding, and the market prospect is very broad.Let’s talk about the knowledge about the mechanical properties of steel channel iron.

Yield point of steel channel iron (σ s )

When the steel section or sample is stretched, when the stress exceeds the elastic limit, even if the stress does not increase, the steel section or sample continues to undergo obvious plastic deformation, which is called yielding, and the minimum stress when yielding occurs value is the yield point. Let Ps be the external force at the yield point s, and Fo be the cross-sectional area of the sample, then the yield point σ s =Ps/Fo(MPa), MPa is called MPa, which is equal to N (Newton)/mm2, (MPa=106Pa, Pa: Pascal=N/m2)

Yield strength of steel channel iron (σ 0.2 )

The yield point of some metal materials is extremely inconspicuous, and it is difficult to measure. Therefore, in order to measure the yield characteristics of the material, the stress when the residual plastic deformation is equal to a certain value (usually 0.2% of the original length) is specified, which is called conditional yielding. Strength or simply yield strength σ 0.2 .

Tensile strength of steel channel iron (σ b )

The stress value that a material reaches during the stretching process, from initiation to fracture. It indicates the ability of the steel channel iron to resist fracture. Corresponding to the tensile strength, there are compressive strength, flexural strength, etc.

Let Pb be the tensile force achieved before the material is broken, and Fo be the cross-sectional area of the specimen, then the tensile strength σ b = Pb/Fo (MPa).

Elongation of steel channel iron (δ s )

After the material is broken, the percentage of its plastic elongation length to the original sample length is called elongation or elongation.

Yield-to-tensile ratio of steel channel iron (σ s/σ b )

The ratio of the yield point (yield strength) to the tensile strength of a steel channel iron is called the yield ratio. The larger the yield ratio, the higher the reliability of the structural parts. Generally, the yield ratio of carbon steel is 0.6–0.65, that of low-alloy structural steel is 0.65–0.75, and that of alloy structural steel is 0.84–0.86.

Hardness of steel channel iron

Hardness indicates the ability of a material to resist the pressing of a hard object into its surface. It is one of the important performance indicators of metal materials. Generally, the higher the hardness, the better the wear resistance. Commonly used hardness indicators are Brinell hardness, Rockwell hardness and Vickers hardness.

⑴Brinell hardness (HB)

Press a hardened steel ball of a certain size (generally 10mm in diameter) into the surface of the material with a certain load (generally 3000kg) and keep it for a period of time. After the load is removed, the ratio of the load to its indentation area is the Brinell hardness value ( HB) in kilogram force/mm2 (N/mm2).

(2) Rockwell hardness ( HR )

When HB>450 or the sample is too small, the Brinell hardness test cannot be used and the Rockwell hardness measurement is used instead. It uses a diamond cone with an apex angle of 120° or a steel ball with a diameter of 1.59 and 3.18mm, which is pressed into the surface of the tested material under a certain load, and the hardness of the material is obtained from the depth of the indentation. According to the different hardness of the test material, it is expressed in three different scales:

HRA: It is the hardness obtained by using a 60kg load and a diamond cone indenter, and is used for extremely hard materials (such as cemented carbide, etc.).

HRB: It is the hardness obtained by using a 100kg load and a hardened steel ball with a diameter of 1.58mm. It is used for materials with lower hardness (such as annealed steel, cast iron, etc.).

HRC: It is the hardness obtained by using a 150kg load and a diamond cone indenter, and is used for materials with high hardness (such as hardened steel, etc.).

⑶ Vickers hardness (HV)

Use a load within 120kg and a diamond square cone indenter with an apex angle of 136° to press into the surface of the material, divide the surface area of the material indentation pit by the load value, which is the Vickers hardness value (HV)

Steel Channel Iron Supplier — XAK

XAK is a professional manufacturer of cold-formed profiles and metal stamping parts. The company mainly produces steel channels, elevated KBK light rails, rigid guide rails, support grooves and their general accessories. Except for conventional shapes such as C, U, Z, L, Furring Hat, etc., mainly OEM steel profiles and accessories according to drawings. Our products are sold all over the world and are trusted and praised by customers all over the world. If you have stainless steel, carbon steel and other materials to be processed, please feel free to contact us.