If the angle bar often costs you too much to maintain. Has not been used for a long time, and has yellowed, rusted, and lost the aesthetics of the work. Not only that, but it also affects the safety of the project.
Then Hot Dipped Galvanized angle bar could be a good choice for you.
Let’s see what hot-dipped galvanized angle bar steel can do.
Advantages of hot-dip galvanized angle bar
Maybe many readers do not know what is hot-dip galvanizing.
Then hot dip galvanized is a form of base metal plating.
By alloying the surface of the base metal by immersing the metal in a bath of molten zinc at a temperature of about 450 °C (842 °F).
When exposed to the atmosphere, pure zinc (Zn) reacts with oxygen (O2) to form zinc oxide (ZnO). It further reacts with carbon dioxide (CO2) to form zinc carbonate (ZnCO3), which is usually dull gray (ash grey).
Readers can visualize this process according to the following chemical equations:
PTPU 1: 2Zn + O2 ➡️ 2ZnO
PTPU 2: ZnO + CO2 ➡️ ZnCO3
The rate at which the reaction takes place will largely depend on:
- The temperature where the angle bar is used
- Catalyst: Because the application of the angle bar is very diverse, it can be in an acidic environment, such as sea salt, …
- The larger the size of V, the larger the contact area, and the higher the rate of the OXH reaction.
- The concentration of corrosive substances: industrial gas H2S, acid, seawater, …
Advantages of hot-dip galvanized angle bar:
- The zinc coating is thick enough to protect the angle bar, protecting your building from the adverse effects of the environment. For example sea vapor, industrial gas, and the environment with toxic chemicals, …
- Good resistance is an advantage, especially in applications where the environment is harsh. This will help your business save quite a lot of maintenance costs.
Processing process of hot-dip galvanized angle bar
Includes the following jobs:
- Mechanical processing: The process gives the steel surface a high degree of uniformity and smoothness, making the plating strong and beautiful. However, it can cause the steel surface to be deformed, reducing the adhesion of the plating layer later. Therefore, it is necessary to activate the steel surface in dilute acid, and then immediately plated it.
- Degreasing: Steel after the production process often adheres to grease. Although it is very thin, it also makes the steel surface inaccessible to bleaching and plating solutions. The following substances can be used for bleaching: trichloroethylene (C2HCl3), tetrachloroethylene (C2Cl4), carbon tetrachloride (CCl4), etc. However, after the solvent evaporates, there is still a very thin grease film on the steel surface. => is not clean. It is necessary to continue bleaching in a hot alkaline solution of NaOH, with the addition of some emulsifiers such as Na2SiO3, and Na3PO4 …
- Rust removal: The surface of the base steel is usually covered with a thick layer of oxide, called rust. Chemical rust removal for black angle bars usually uses dilute H2SO4 or HCl or a mixture thereof. When bleaching usually takes place at the same time 2 processes: dissolve the oxide and the base metal.
- Electrochemical polishing: Helps angle bar surface have better shine.
- Light eraser: Also known as surface activation (flux immersion). To remove the very thin, invisible oxide layer that is formed during machining immediately prior to plating. When light bleaching is completed, the crystal structure of the substrate is exposed, and adhesion will increase.
Step 2: Galvanized
The angle bar is immersed in a molten zinc solution at a temperature of 450 degrees Celsius. Until the zinc layer has a standard thickness. Then remove the steel from the dip tank. And proceed to remove excess slag and zinc on the pipe by dipping the steel in chromate solution.
Step 3: Cool down and check the quality
Application of hot-dip galvanized angle bar
Hot dipped galvanized angle bar steel is used to:
- Used as bearing bars such as bars of the truss: by using 1 or 2-angle steel bars to form a T-section or a cross.
Used to bond with other steels to create composite structures. Like joining with steel plates to form hollow column sections, and I-beam cross-sections, …
- In particular, a hot-dip galvanized angle bar is always the preferred choice for projects with harsh environments.