Welding Electrodes E308L-16

Welding rods are consists of one core rod and flux coating.

Usually, the tip end of the welding rod has a chamfer, and a part of the welding core rod exposed at the tip end .

Some welding rods have arc starting agents dipped at the end which make it easier to start the ARC. like, blue tip end, green tip end, yellow tip end ,etc

The welding rod grade nos are printed on the coating near the clamping end, like AWS E308L-16,AWS E308L-15, AWS E308H, AWS E308-16
The metal core covered by the coating in the welding rod is called the welding core.

During doing the arc- welding, an electric arc is generated between the welding core and the workpiece, which melts into the filler metal of the weld seam. The soldering core is both an electrode and a filler metal.

According to the AWS standards A5.14"Stainless Steel Wire for Welding", specialized metal wires (called welding wires) used for welding cores are divided into three categories: carbon structural steel, low-alloy structural steel, and stainless steel.

The composition of the welding core will directly affect the composition and properties of the deposited metal.

The welding cores (steel wires) used for various types of welding rods are shown as below .

Mild steel welding rods	Core rods: H08A,etc
Stainless steel welding rods	Core rods: stainless steel rods,like 308,316,309
Cast iron welding rods	Core rods:nickel alloy rods ,like Ni 55%, Ni 99%
Hardfacing welding rods	Core rods : Carbon steel rods ,stainless steel rods,
Non-Ferrous welding rods	Core rods: various of non-ferrous core rods, like RBCUZN-C

 

The effective ingredient applied to the surface of the solder core is called coating flux .

Welding rod coating is a layer of coating applied to the surface of the welding core by pressing a certain proportion of raw materials such as ore powder, iron alloy powder, organic matter, and chemical products.

Its function is to:
1. Mechanical protection
After the melting or de-composition of the electrode coating, gas and slag are generated, and the air is isolated to prevent the molten droplets and molten pool metal from coming into contact with the air. The solidified slag shell covers the surface of the weld seam, which can prevent the high-temperature weld metal from being oxidized and nitrided, and can slow down the cooling rate of the weld metal.
2. Metallurgical processing
Through welding metallurgical reactions such as deoxidation, desulfurization, dephosphorization, dehydrogenation, and alloying using slag and ferroalloys, harmful elements can be removed, useful elements can be added, and the weld seam can have good mechanical properties.
3. Improve welding process performance
The coating can ensure that the arc is easy to ignite and steadily burns continuously; Simultaneously reducing splashing, improving droplet transfer and weld formation.
4. Infiltration alloy
The coating of welding rods contains alloy elements that melt and transition into the molten pool, which can improve the properties of the weld metal.