How Much Do You Know About The Letter Symbol Of Welding Rod?

Aug 15, 2019

Welding materials for manual arc welding electrode: internal steel core and outer coating

1. The steel core mainly conducts electricity and forms a deposited metal with a certain composition at the end of the electrode. Require the core to minimize the content of harmful elements, limit S, P, some welding rod requirements control As (arsenic), Sb (antimony), Sn (tin) and other elements.

2. The coating, also known as coating, ensures that the deposited metal has a certain composition and performance. Using oxide, carbonate, silicate, organic matter, fluoride, ferroalloy and chemical products and other hundreds of raw materials powder, according to a certain proportion of formula mixed.

Functions of various components in the skin:

1) arc stabilizing agent: all easily ionized substances can stabilize the arc. Alkali metal and alkaline earth metal compounds, potassium carbonate, sodium carbonate, marble, etc.

2) slagging agent: form dissolved slag, cover the molten metal surface, protect the molten pool and improve the weld forming.

3) deoxidizer: reduce oxygen content and improve mechanical properties. The main deoxidizer is ferromanganese, ferrosilicon, titanium iron.

4) gasifier: decompose gas at high temperature to protect arc and molten pool and prevent oxygen and nitrogen from intruding into the air.

5) alloying agent: to compensate the burning loss of alloying elements and transfer alloying elements to the weld, so as to ensure the chemical composition and properties of the weld.

6) plasticizing lubricant: increase the plasticity, slippage and fluidity of the powder in the process of welding rod compression coating, so as to improve the quality of welding rod compression coating and reduce eccentricity.

7) adhesive: make the coating powder have a certain viscosity in the process of pressing and coating, and secure the welding core, and make it have a certain strength after drying.

Welding electrode usage:

Acid electrode and alkaline electrode are classified by alkalinity of slag.

Acid electrode welding technology is good, forming neat, easy to remove slag, not easy to produce pores and slag inclusion. However, the oxidation strength of the coating leads to a large loss of alloying elements and low mechanical properties (impact toughness). Acid electrode can be used in general ac or dc power supply. A typical acid electrode is J422.

The welds with alkaline electrode have good mechanical properties, especially high impact toughness, which is mainly used for the welding of important structures. Fluoride dust harmful, should strengthen the field ventilation exhaust, in order to improve working conditions. Typical alkaline electrodes are J507.

According to the main components of electrode coating classification

Titanium-calcium type occurs when the skin contains more than 30% titanium dioxide and less than 20% calcium and magnesium carbonate.

Carbon steel welding rod model number

In E4315, "E" means electrode; The first two digits represent the minimum tensile strength of the deposited metal, and the unit is 1/10 of the MPa value. The third digit represents the welding position of the electrode, "0" and "1" for all-position welding (horizontal, vertical, vertical and horizontal), "2" for flat and fillet welding, and "4" for downward vertical welding; The combination of the third and fourth digits indicates the type of welding current and skin type.

The common used electrode

A. titanium calcium electrode type E4303, E5003. Mainly used for more important carbon steel structure.

B. E4315, E5015 low sodium hydrogen electrode type, mainly used for important low carbon steel structure and low alloy steel structure, also used for welding high sulfur steel and painted steel

C. E4316, E5016 electrode low hydrogen potassium type, stable arc, mainly used for important low carbon steel and low alloy steel structure.

Low alloy steel electrode type E5018-A1, suffix letter for the chemical composition of deposited metal classification code

Stainless steel electrode type e308-15, the letter E stands for welding rod, the number after "E" stands for the classification code of chemical composition of deposited metal, and the two Numbers after short "-" represent the type of electrode coating, welding position and welding current type.