Q345B Angle Steel

Q345B Angle Steel

Q345B angle steel is a carbon structural steel that can withstand heavy loads and stresses. Like other steels in this grade, it can endure elongation before pulling apart, usually at 20 percent of its initial length.

Moreover, it can be used in all kinds of building structures and engineering structures, such as beams, bridges, transmission tower, lifting transportation machinery, ships, industrial furnace,container frame and warehouse shelves.

Mechanical Properties

Q345B angle steel can endure a lot of stress and pressure before it breaks or bends. This strength makes it a good choice for construction and infrastructure projects, as well as industrial machinery and equipment. It also has great low temperature performance, plasticity and weldability, making it ideal for fabrication applications.

The tensile strength of Q345B is rated at 470 to 660 Mega Pascals, which means it has great strength for its size. The Brinell hardness of this grade is measured by the depth of penetration of an indenter on the material’s surface. The higher the Brinell number, the harder the material.

When compared to Q235 grade steel, Q345B has greater strength and higher welding properties. It also has better fatigue resistance than its counterpart. It is important to note that the corrosion resistance of this grade of steel is less than other types.

The effect of repair welding on the evolution of microstructure and properties in SUS304-Q345B dissimilar steel weld was systematically studied through microstructure observation, mechanical properties tests, and corrosion resistance tests. It could be found that the USP treatment significantly improved the microstructure and properties of the weld in comparison to the un-USPed samples. The surface morphology of the USPed samples in Q345B angle steel 3.5 wt.% NaCl solution were different from that of the un-USPed samples, with minor abrasive traces and serious corrosion on their corroded surfaces.

Chemical Composition

Q345B is a low alloy steel with less than 0.2% carbon, and the rest of its composition is made up of silicon and several impurities (such as sulfur, nickel, and chromium). It has a low tensile strength, but its yield strength is much higher. This allows it to withstand large amounts of stress without breaking or becoming deformed.

The chemical composition of Q345B is different from that of 16Mn steel, which is why it is not used to replace one another directly. The difference in the yield strength between the two materials will cause a change in the allowable stress for the material of some thicknesses. This is why it is important to re-determine the allowable stress of the new steel grade according to the yield strength of the original steel.

Q345B is a low-alloy structural steel that offers good performance at low temperatures and good weldability. It is commonly used in oil tanks, bridges, vehicles, cranes, mechanical parts, and general metal constructions. It is also suitable for use in areas that will be exposed to high loads and cold environments. It is similar to ASTM A572 grade 50 in terms of its properties. In addition, it is easy to form and shape. However, it does not have good corrosion resistance. To improve the corrosion resistance of this grade, it can be strengthened with ultrasonic shot peening (USP). In this study, USPed samples were immersed in 3.5 wt.% NaCl solution for 3 days, and the surface morphology and roughness of the samples were studied.

Welding Properties

Q345B angle steel can be welded using both electric arc and gas welding. Its low temperature performance is excellent, and its welding hardness is high. It is often used in cold regions and for structural metal parts, such as bridges, vehicles, oil tanks, cranes, buildings, and pressure vessels.

The tensile strength of a material is the amount of force that can be applied to it before it fails, such as breaking or crushing. It is measured in units of force per cross-sectional area, known as Pascals (Pa).

Steel tensile strength can be affected by the welding process and by the type of welding equipment used. For this reason, it is important to follow proper welding procedures when working with this type of material.

In addition, the welding process can also affect corrosion resistance. When a weld is exposed to moisture, it can lead to pitting and cracking. Fortunately, this type of damage can be prevented by following proper welding techniques and by choosing an appropriate welding electrode.

The corrosion behavior of the welded specimens was studied by immersion testing in 3.5 wt.% NaCl solution for 3 and 7 days. The corrosion results showed that the welded specimens had a high corrosion resistance, which was due to the Cr and Ni alloying elements in the welding filler.

Corrosion Resistance

Q345B angle steel is a low-alloy high-strength structural steel manufactured with a minimum yield strength of 345 MPa. It has good welding and cold forming properties, as reinforcing bar well as corrosion resistance. It can be used in a variety of applications, including bridges, construction projects, and engineering structures.

This research was aimed at optimizing the process parameters of ultrasonic shot peening (USP) for improving both strength and corrosion resistance of Q345B steel. Different USP process variables were studied, such as the USP time, power and distance, in order to investigate their influence on the surface morphology of the sample, roughness and microhardness. The electrochemical test polarization curves of the samples were also recorded, and their corrosion potentials and current densities were determined.

The results indicated that the corrosion resistance of welds R1 and R2 was superior to that of base material BMSUS304, and this improvement was attributed to the finer grain size and better d-ferrite morphology in the welds. In addition, the corrosion resistance of R1 weld was remarkably improved after repair welding, whereas that of R2 weld was worse, mainly due to a pro-eutectoid austenite and coarsening pearlite.

Q345B is a Chinese standardized low-alloy medium-tensile strength manufacturing steel grade, with carbon less than 0.55 percent and silicon and several impurities, such as sulfur, phosphorus, and chromium. It is widely used in a variety of metal constructions that are subject to high-loads, such as bridges and vehicles, and in cold regions.

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